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ERRORLESS MATERIAL
2025-26

STANDARD

11
BIO-ZOOLOGY
BOOK BACK
Q/A
N.SENTHILKUMAR
PGT IN ZOOLOGY
GBHSS,THALAIVASAL(TK)
SALEM (DT)

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Chapter -1
The Living World
9.Differentiate between probiotics and pathogenic bacteria.

Probiotics Pathogenic Bacteria

1.Beneficial bacteria. 1.Harmful bacteria.
2.They maintain gut health and take 2.They cause severe illness which
care of the gastrointestinal tract. needs prevention and treatment.
3.Curd is one of the best sources of
3.Example – M.tuberculosis
probiotics. Example - Lactobacillus sp.

10. Why mule is sterile in nature?

 Crosses between Male Donkey and Female Horse results in Mule
 Mule gets one set of chromosomes (32) from male donkey and one set of
chromosomes (31) from female horse.
 These two sets of chromosomes do not match with each other and cannot
produce gametes by meiosis. Hence mule is sterile in nature.

11. List any five salient features of the family Felidae.

 They are commonly called as wild cat family
 They have adaptations to detect and hunt prey.They are carnivores.
 They have cutting teeth to shear meat. Canine teeth are large and sharp.
 They have acute sense of hearing, smell, vision and touch.
 They have well padded toes with powerful claws and flexible bodies.Eg: Cat.

12. What is the role of Charles Darwin in relation to concept of species?

 In 1859 Charles Darwin in his book Origin of species explains the
evolutionary connection of species by the process of natural selection.
 Darwin defined evolution as "descent with modification," the idea that
species change over time, give rise to new species, and share a common
ancestor.

13. Why elephants and other wild animals are entering into human living
area?
 Elephants and other wild animals enter into human living area because of
the loss of their habitat, deforestation, mono-culture vegetation by
destroying forests.

14. What is the difference between a Zoo and wild life sanctuary?

Zoo Wildlife sanctuary

1.Zoo is a place where animals are 1.Sanctuaries are protected regions where
maintained for public display. wild animals live in natural habitats.
2 It is a collection of animals
gathered from all around the 2.It contains animals native to that area.
country .
3.It is an artificial habitat. 3.It is a natural habitat.
4.They are small areas where 4.They are large areas where animals are
animals are kept in cages. free to move anywhere.

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15. Can we use recent molecular tools to identify and classify organisms?
 Yes.
 DNA barcoding (short genetic marker in an organism’s DNA to identify it as
belonging to a particular species)
 DNA hybridization (measures the degree of genetic similarity between pools
of DNA sequences)
 DNA fingerprinting (to identify an individual from a sample of DNA by looking
at unique patterns in their DNA)
 Restriction Fragment Length Polymorphisms (RFLP) analysis (difference in
homologous DNA sequences that can be detected by the presence of fragments
of different lengths after digestion of the DNA samples)
 Polymerase Chain Reaction (PCR) sequencing ( to amplify a specific gene, or
portion of gene,) are used as taxonomical tools.

16. Explain the role of Latin and Greek names in Biology.

 Greek or latin language is also referred to as the dead language, meaning that
no changes can be done in the language ,it remains constant and no new
words are added.
 To maintain the uniformity of scientific names all throughout the world,
latin/greek is used in biology.
Chapter -2
Kingdom Animalia
22. Why are spongin and spicules important to a sponge?
 Spongin and spicules are important to a sponge because they provide support
and structure and protect the sponge from predators.

23. What are the four characteristics common to most animals?

 Cell structure, movement, consumer habits and reproduction habits.

24. List the features that all vertebrates show at some point in their
development.
 Notochord, dorsal hollow nerve cord, pharyngeal gill slits, ventral heart and
post-anal tail.
25. Compare closed and opened circulatory system.
Closed circulatory system Open circulatory system
1.It is found in vertebrates and a few 1.It is primarily found in
invertebrates like earthworms. invertebrates.
2.This system has vessels that 2.Blood flows freely through cavities
conduct blood throughout the (haemolymph) since there are no
body vessels to conduct the blood.
Eg. All mammals Eg. Insects

26. Compare Schizocoelom with enterocoelom.

Schizocoelomates Enterocoelomates
1.In these animals the body cavity is 1.The body cavity is formed from the
formed by splitting of mesoderm. mesodermal pouches of
archenteron.
Eg.Annelids and arthropods. Eg.Hemichordates and chordates.

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27. Identify the structure that the archenteron becomes in a developing

animal.
 The archenteron becomes the cavity of the digestive tract.

28. Observe the animal below and answer the following questions.
 Identify the animal- Sea anemone.
 What type of symmetry does this animal exhibit? -Radial symmetry.
 Is this animal Cephalized? -No.
 How many germ layers does this animal have? Two (ectoderm and
endoderm)
 How many openings does this animal’s digestive system have? -One.
 Does this animal have neurons?- No (Have a nerve net)

29. Choose the term that does not belong in the following group and explain
why it does not belong?
Notochord, cephalisation, dorsal nerve cord and radial symmetry.

 Radial symmetry- Radial symmetry is a characteristic of Invertebrates such

as starfish and sea anemones.
 It refers to a body that can be divided into two similar halves by passing a
plane across it at any angle.
 Notochord, cephalization, and dorsal nerve cord are characteristic features of
chordates, which are animals with bilateral symmetry.

30. Why flatworms are called acoelomates?

 Flatworms are called acoelomates because they do not have a body cavity.
 Their body is solid without a perivisceral cavity, this restricts the free
movement of internal organs.

31. What are flame cells?

 Flame cells are specialized excretory cells which help in osmoregulation
and excretion. Eg. Platyhelminthes

32. Concept Mapping - Use the following terms to create a concept map that
shows the major characteristic features of the phylum nematoda:
Round worms, pseudocoelomates, digestive tract, cuticle, parasite,
sexual dimorphism.

33. In which phyla is the larva trochopore found?

 Annelida and Mollusca

34. Which of the chordate characteristics do tunicates retain as adults?

 Pharyngeal gill slits

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35. List the characteristic features that distinguish cartilaginous fishes with
living jawless fishes.
Cartilaginous fishes Jawless fishes
1.All members of cyclostomata
1.They are marine fishes with are primitive, poikilothermic,
cartilaginous endoskeleton. jawless aquatic vertebrates and
Notochord is persistent throughout life. are ectoparasites on some
fishes.
2 .Skin is tough covered by placoid scales 2.Body is slender and eel-like
and the caudal fin is heterocercal bearing six to fifteen pair of gill
slits for respiration.
3.Mouth is located ventrally and teeth 3.Mouth is circular without jaws
are modified placoid scales and suctorial. Heart is two
chambered and circulation is of
closed type.
4.Respiration by lamelliform gills without 4.No paired appendages.
operculum (gill cover).
5.Excretory organs are mesonephric 5.Cyclostomes are marine but
kidneys. Two chambered heart is migrate to fresh waters for
present. spawning (anadromous
migration).
6.Ureotelic,poikilothermic and 6.External fertilization.The larvae
viviparous. Sexes are separate. In (ammocoete) after
males pelvic fins bear claspers to aid in metamorphosis returns to the
internal fertilization. ocean.
Eg.Scoliodon (Shark) Eg. Petromyzon (Lamprey)
36. List three features that characterise bony fishes.
 Bony endoskeleton and spindle shaped body.
 Air bladder helps in gaseous exchange and buoyancy.
 Skin is covered by ganoid, cycloid or ctenoid scales.
 Respiration is by four pairs of filamentous gills and is covered by an
operculum. They have a ventrally placed two chambered heart
 Excretory organs are mesonephric kidneys and are ammonotelic.
 Presence of well developed lateral line sense organs.
 Sexes are separate, external fertilization is seen and most forms are oviparous

37. List the functions of air bladder in fishes.

 Air bladder is present with or without a connection to the gut.
 It helps in gaseous exchange (lung fishes) and for maintaining buoyancy in
most of the ray finned fishes in most of the ray finned fishes.
38. Write the characteristics that contributes to the success of reptiles on
land.
 They are mostly terrestrial animals and their body is covered by dry, and
cornified skin with epidermal scales.
 Reptiles have three chambered heart but four chambered in crocodiles.
 Reptiles breathe entirely through their lungs
 All are cold blooded amniotes (poikilotherms).
 Most reptiles lay cleidoic eggs (oviparous) with extra embryonic membranes
like amnion, allantois, chorion and yolk sac. Internal fertilization
 Excretion by metanephric kidneys and are uricotelic.
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39. List the unique features of bird’s endoskeleton.

 The endoskeleton is fully ossified (bony) and the long bones are hollow with
air cavities (pneumatic bones).

40. Could the number of eggs or young ones produced by an oviparous and
viviparous female be equal? Why?
 Not equal.
 The numbers of eggs produced by an oviparous mother will be more than
the young ones produced by a viviparous mother.
 This is because, in oviparous animals, the development of young ones takes
place outside the mother's body.

Chapter -3
Tissue Level of Organisation

6. Some epithelia are pseudostratified. What does this mean?

 Pseudo-stratified epithelial cells are columnar, but unequal in size.
 Although the epithelium is single layered yet it appears to be multi-layered
because the nuclei lie at different levels in different cells.

7. Differentiate white adipose tissue from brown adipose tissue.

White adipose tissue Brown adipose tissue
1.‘White fat’ or white adipose tissue 1.‘Brown fat’ or Brown adipose tissue
contain abundant mitochondria
2.It is used to heat the blood stream
2.White fat stores nutrients to warm the body. It produces heat
present under the skin. by non-shivering thermo genesis in
neonates.

8. Why blood is considered as a typical connective tissue?

 Blood is the fluid connective tissue containing plasma, red blood cells (RBC),
white blood cells (WBC) and platelets.
 It functions as the transport medium for the cardiovascular system, carrying
nutrients, wastes, respiratory gases throughout the body.

9. Differentiate between elastic fibres and elastic connective tissue.

Elastic fibres Elastic Connective Tissue
1.Fibres and fibroblasts are 1.It contains high proportion of elastic
compactly packed in the dense fibres.
connective tissues.
2.Dense regular connective tissues
primarily contain collagen fibres 2.It allows recoil of tissues
(Fibroblast)
3.It attaches muscles and bones 3.It maintains the pulsatile flow of
and withstands great tensile blood through the arteries and the
stress when pulling force is passive recoil of lungs following
applied in onedirection. inspiration.

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4.This connective tissue is present in 4.It is found in the walls of large

tendons, that attach skeletal arteries ligaments associated with
muscles to bones and ligaments vertebral column and within the
attach one bone to another. walls of the bronchial tubes.

10. Name any four important functions of epithelial tissue and provide at
least one example of a tissue that exemplifies each function.
 Protection, absorption, excretion, secretion.
 Simple squamous epithelium: Allows the easy passage of gases by diffusion
and fluids by filtration
 Simple cuboidal epithelium: Helps in secretion and storage
 Columnar epithelium: Concerned with absorption and secretion
 Ciliated pseudostratified columnar epithelium: Allows the movement of
particles, which helps in the excretion of foreign particles and the secretion of
mucus

11. Write the classification of connective tissue and their functions.

 Loose connective tissue
 Dense connective tissue
 Specialized connective tissue
 Loose connective tissues- The cells and fibres are loosely arranged in a semi
fluid ground substance. They are classified as
1.Areolar connective tissue- It lies beneath the skin, Acts as a support for
epithelium. Acts as reservoir of water and salts for the surrounding body
tissues. Hence it is called tissue fluid.
2.Adipose Tissue
Found below the skin. 90% of the tissue contains Adipocytes or fat cells.
Richly vascularised and supplies energy to the body while fasting.
(i) White fat : (White adipose tissue) Found in subcutaneous tissue
surrounding kidneys, eye ball etc. It Store nutrients.
(ii) Brown fat : (Brown adipose tissue) contains abundant mitochondria. Used
to heat the blood stream to warm the body.
Reticular connective tissue : Matrix is filled with fibroblasts called reticular
cells. Forms an internal framework that supports the blood cells in the lymph
nodes, spleen and bone marrow.
 Dense connective tissues
Fibres and fibroblasts are compactly packed based on orientation of fibres it is
divided into:
1. Dense regular connective tissues-Primarily collagen fibres are arranged
in rows between parallel bundles of tissues and few elastic fibres.
Fibroblast is the major cell type.
Present in tendons that attach skeletal muscles to bones and ligaments.
Bones are attached to one another by ligaments. The tissue withstands tensile
strength when pulling force is applied in one direction.
2. Dense irregular connective tissues- Have bundles of thick collagen fibres
and fibroblasts arranged irregularly. Fibroblast is the major cell type.
Functions: The tissue can withstand tension exerted in many directions. Some
elastic fibres are also present.

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3. Elastic connective tissue- It contains high proportion of elastic fibres and

allows recoil of tissues following stretching. Eg: Walls of arteries.
 Specialised connective tissues-Classified as cartilage, bones and blood.
1.Cartilage
Intercellular material is solid and pliable and resists compression. Cells of this
tissue matrix secreted by them. Eg: Cartilage in ear pinna, Tip of nose etc.
2.Bones
Hard and non pliable ground substance rich in calcium salts and collagen
fibres which gives strength. cells or osteocytes are present in spaces called
lacunae.Bones support and protect softer tissues and organs. Bone marrrow
is site of production of blood cells.
3.Blood
Fluid connective tissue containing plasma, RBC, WBC and platelets.
Transport medium for the cardiovascular system carrying nutrients, wastes,
respiratory gases throughout the body.
12. What is an epithelium? Enumerate the characteristic features of
different epithelia.
 Epithelial tissue is a sheet of cells that covers the body surface. It occurs in
the body as a covering, as a lining epithelium and as glandular, epithelium.
 Functions: Protection, absorption, filtration, excretion, secretion and
sensory reception.
I)Simple Epithelium : Single layer of cells found in organs of absorption,
secretion and filtration. They are classified into
1. Squamous epithelium : Single thin layer of flattened cells with irregular
boundaries.It forms a diffusion boundary and help in filtration.
2. Cuboidal epithelium : Single layer of cube like cells. Functions are
absorption, secretion of mucus etc.
3. Columnar epithelium: Composed of single layer of tall cells with round
to oval nuclei at base. Function are absorption, secretion of mucus etc.
4. Ciliated epithelium: Propels mucus by ciliary actions and occur in
bronchi, uterus etc. Non-ciliated type is seen in gall bladder.
5. Pseudo-stratified epithelium: Columnar cells but unequal in size.
Although epithelium is single layered, it appears to be multilayered because
the nuclei lie at different levels in different cells. Functions are protection,
secretions, movement of secretions from glands etc.
6.Some of the cuboidal or columnar epithelial cells get specialized for
secretion.
i).Unicellular Isolated glandular cells. Eg: Goblet cells of alimentary canal.
ii) Multicellular Cluster of cells. Eg. Salivary glands.
7.The secretions of exocrine glands are carried by tubes/ducts.
8. The secretion of endocrine glands are poured into blood steam.

II.Compound epithelium:
Multilayered tissue. -Protection against chemical and mechanical stresses.
They occur in dry surface of the skin, moist surface of buccal cavity etc.,
Compound epithelium is divided into the four types.
1. Stratified squamous epithelium :
a). Keratinized type Eg: Dry epidermis of the skin.
b). Non keratinized type Eg: Moist lining of the oesophagus, mouth,

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conjunctiva of the eyes and vagina.

2. Stratified cuboidal epithelium Eg:Ducts of sweat glands.
3. Stratified columnar epithelium Eg:Pharynx.
4. Transitional epithelium Eg:Urinary bladder.

Chapter -4
Organ and Organ Systems in Animals
14. What characteristics are used to identify the earthworms?
 It is light brown in colour with purple tinge at the anterior end ,long and
cylindrical narrow body, bilateral symmetry and segmented body.

15. What are earthworm casts?

 The undigested particles along with soil are passed out through the anus,
as worm castings or vermicasts.

16. How do earthworms breathe?

 Respiration takes place through the body wall.
 Body wall is richly supplied with blood capillaries which aid in the diffusion of
gases.(O2 and CO2).The skin is kept moist by mucous and coelomic fluid.

17. Why do you call cockroach a pest?

 Cockroach carry harmful germs of various bacterial diseases like cholera,
diarrhoea, tuberculosis, and typhoid and hence are known as “Vectors”

18. Comment on the functions of alary muscles?

 The triangular muscles that are responsible for blood circulation in the
cockroach are called alary muscles (12 pairs).
 One pair of these muscles is found in each segment on either side of the heart.

19. Name the visual units of the compound eyes of cockroach.

 Each eye is formed of about 2000 simple eyes called the ommatidia through
which the cockroach can receive several images of an object.
 This kind of vision is known as mosaic vision with more sensitivity but less
resolution.

20. How does the male frog attracts the female for mating?
 The male frog has a pair of vocal sacs.
 Vocal sacs assist in amplifying the croaking sound of frog to attracts the
female.

21. Write the types of respiration seen in frog.

 Cutaneous respiration by skin.
 Buccal respiration by buccal cavity.
 Pulmonary respiration by lungs.

22. Differentiate between peristomium and prostomium in earthworm.

 The mouth is found in the centre of the first segment of the body, called the
peristomium.

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 Overhanging the mouth is a small flap called the upper lip or prostomium.

23.Give the location of clitellum and spermathecal openings in Lampito

mauritii.
 Clitellum - From 14th-17th segments.
 Spermathecal openings - 6/7, 7/8 and 8/9 segments.(Three pairs)

24. Differentiate between tergum and a sternum.

 In cockroach the sclerites of the dorsal side are called tergites, those on the
ventral side are called sternites.

25. Head of cockroach is called hypognathous. Why?

 The head of cockroach is small, triangular lies at right angle to the
longitudinal body axis.
 The mouth parts are directed downwards so it is hypognathous.
 It is formed by the fusion of six segments and shows great mobility in all
directions.

26. What are the components of blood in frog?

 The blood consists of plasma [60%] and blood cells [40 %] which includes red
blood cells, white blood cells, and platelets.
 RBCs are loaded with red pigment, nucleated and oval in shape. Leucocytes
are nucleated, and circular in shape
27. Draw a neat labeled diagram of the digestive system of frog.

28. Explain the male reproductive system of frog.

 The male frog has a pair of testis which are attached to the kidney and the
dorsal body wall by folds of peritonium called mesorchium.
 Vasa efferentia arise from each testis. They enter the kidneys on both side
and open into the bidder’s canal.
 Finally, it communicates with the urinogenital duct that comes out of
kidneys and opens into the cloaca.

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29. Explain the female reproductive system of frog.

 Female reproductive system consists of paired ovaries, attached to the
kidneys, and dorsal body wall by folds of peritoneum called mesovarium.
 There is a pair of coiled oviducts lying on the sides of the kidney.
 Each oviduct opens into the body-cavity at the anterior end by a funnel like
opening called ostia.
 Female frog has separate genital ducts distinct from ureters.
 Posteriorly the oviducts dilated to form ovisacs before they open into cloaca.
Ovisacs store the eggs temporarily before they are sent out through the cloaca.
Fertilization is external.

30. Differentiate between male and female cockroach?

S. No Character Male cockroach Female cockroach

1. Abdomen Long and narrow Short and broad
In the abdomen, nine In the abdomen, seven
2. Segments
segments are visible segments are visible
3. Anal styles Present Absent
7th tergum covers 8th 7th tergum covers 8th
4. Terga
tergum and 9th terga

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Brood
5. Absent Present
pouch
6. Antenna Longer in length Shorter in length
Extends beyond the tip of Extends up to the end of
7. Wings
abdomen abdomen

Chapter -5
Digestion and Absorption
17. Why are villi present in the intestine and not in the stomach?
 Because digestion of carbohydrate, protein and lipid is not completed in
stomach.
 The stomach stores food temporarily and helps in partial digestion of
proteins while the small intestine absorbs nutrients through villi.

18. Bile juice contains no digestive enzymes, yet it is important for

digestion. Why?
 Bile helps in emulsification of fats. Bile salts reduce the surface tension of
fat droplets and break them into small globules.
 Bile also activates lipases to digest lipids.

19. List the chemical changes that starch molecule undergoes from the time
it reaches the small intestine.
 Salivary amylase(ptyalin) partially digests starch into maltose.
 Pancreatic amylase in the pancreatic juice breaks down starch into maltose,
a disaccharide.
 Maltase, an enzyme secreted by the small intestine, converts maltose into
glucose.

20.How do proteins differ from fats in their energy value and their role in
the body?
 The caloric value and physiological fuel value of one gram of protein are 5.65
Kcal and 4 Kcal respectively.
 Proteins are source of amino acids required for growth and repair of body
cells. The daily requirement 1gm per 1 kg body weight.
 Fat has a caloric value of 9.45 Kcal and a physiological fuel value of 9 Kcal
per gram.
 Lipids stored in our body which is used for production of energy.

21. Digestive secretions are secreted only when needed. Discuss.

 Sight, Smell, Taste as well as the mechanical stimulation of food in the
mouth, triggers a reflex action which results in the secretion of saliva and
digestive enzymes.
 The passage of food into the stomach, Duodenum, and small intestine,
stimulate the secretions and there by facilitate digestion.

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Chapter -6
Respiration
17. Respiratory organs of
Flatworm-Body surface Earthworm- Moist skin Fish- Gills
Prawn- Gills Cockroach-Trachea. Cat-Lungs.

18. Name the enzyme that catalyses the bicarbonate formation in RBCs.
 Carbonic anhydrase

19.Air moving from the nose to the trachea passes through a number of
structures. List in order of the structures.
 External nostrils, nasal cavity, pharynx and larynx.

20.Which structure seals the larynx when we swallow?

 Epiglottis
21.Resistance in the airways is typically low. Why? Give two reasons.
 The diameter of most airways is relatively large.
 For smaller air ways there are many in parallel, making their combined
diameter large.
 Air has a low viscosity.

22.How the body makes long–term adjustments when living in high altitude.
 The kidneys accelerate production of the hormone erythropoietin, which
signals the bone marrow to produce more RBCs.

23. Why is pneumonia considered a dangerous disease?

 Inflammation of the lungs due to infection caused by bacteria or virus is
called pneumonia.
 The common symptoms are sputum production, nasal congestion,
shortness of breath, sore throat etc.

24. Diffusion of gases occurs in the alveolar region only and not in any other
part of the respiratory system. Discuss.
 The alveolar region is highly vascular. Each alveolus is made up of highly
permeable and thin layers of squamous epithelial cells.
 The barrier between the alveoli and the capillaries is thin and diffusion of
gases take place from higher partial pressure to lower partial pressure.

25.Sketch a flow chart to show the path way of air flow during respiration.
 External nostrils→nasal cavity→ pharynx→larynx→trachea→ primary
bronchi→secondary bronchi→tertiary bronchi → bronchioles →alveoli.

26.Explain the conditions which creates problems in oxygen transport.

 When a person travels quickly from sea level to elevations above 8000ft,
where the atmospheric pressure and partial pressure of oxygen are lowered.
 It cause acute mountain sickness (AMS)– headache, shortness of breath,
nausea and dizziness due to poor binding of O2 with haemoglobin.

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 To overcome this situation for long–term basis kidneys accelerate production

of the hormone erythropoietin, which stimulates the bone marrow to
produce more RBCs.
 When a person descends deep into the sea, the pressure in the surrounding
water increases which causes the lungs to decrease in volume and Increases
partial pressure of the gases within the lungs.
 This effect can be beneficial, because it tends to drive additional oxygen
into the circulation, but this benefit also has a risk, the increased pressure
can also drive nitrogen gas into the circulation lead to a condition called
nitrogen narcosis.
 When the diver ascends to the surface too quickly a condition called ‘bends’
occurs and nitrogen comes out of solution while still in the blood forming
bubbles.
 Small bubbles in the blood are not harmful, but large bubbles can lodge in
small capillaries, blocking blood flow or can press on nerve endings.
 Leads to pain in joints and muscles and neurological problems including
stroke.It is common in scuba divers.

Chapter -7
Body Fluids and Circulation
15. Distinguish between arteries and veins.
Arteries Veins
1.The blood vessels that carry blood The blood vessels that carry blood to
away from the heart are called heart are called veins.
arteries.
2.The arteries usually lie deep inside Veins have thinner walls and a larger
the body. The largest artery, the lumen and hence can be easily
aorta stretched.
3.The walls of the arteries are thick,
The blood pressure is low and the lumen
non- collapsible to withstand high has a wide wall which is collapsible.
pressure
4.Tunica externa,Tunica media, Tunica externa,Tunica media,Tunica
Tunica intima are present intima are present.
5.Tunica media is thicker in arteries Tunica media is thinner in veins.
6.Valves are absent and have a Presence of valves that prevents
narrow lumen backflow of blood.
7.All arteries carry oxygenated blood, They carry deoxygenated blood
except the pulmonary artery except, the pulmonary vein.

16. Distinguish between open and closed circulation.

Open circulatory system Closed circulatory system

1)It has haemolymph as the
1)Blood is pumped by the heart
circulating fluid and is pumped by
and flows through blood
the heart, which flows through blood
vessels.
vessels into the haemocoel.
Eg. Arthropods and most Molluscs. Eg. Annelids and Vertebrates.
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17. Distinguish between mitral valve and semi lunar valve.

 The opening between the left atrium and the left ventricle is guarded by the
mitral valve or bicuspid valve.
 Semi lunar valves are paired valves of the heart at the bases of the aorta and
the pulmonary artery.
 The valves of the heart allow the blood to flow only in one direction.
 It prevents backward flow of blood.

18. Right ventricular wall is thinner than the left ventricular wall. Why?
 The left ventricle needs to generate more pressure to pump blood
throughout the body, so its wall is thicker.
 The right ventricle only needs to pump blood a short distance to the lungs,
so its wall is thinner.

19. What might be the effect on a person whose diet has less iron content?
 Iron deficiency leads to anemia, tiredness and shortness of breath.

20. Describe the mechanism by which the human heart beat is initiated and
controlled.
 The heart in human is myogenic, rhythmic depolarisation that initiates
contractions.
 Pacemaker located in the right sinuatrial node.(SA node)
 On the left side of the right atrium is a node called auriculo ventricular
node (AV node).
 Two special cardiac muscle fibres originate from the auriculo ventricular
node and are called the bundle of His which runs down into the
interventricular septum and the fibres spread into the ventricles. These
fibres are called the Purkinje fibres.
 Early depolarisation is slow and takes place by sodium influx and reduction
in potassium efflux.
 Minimum potential is required to activate voltage gated calcium (Ca+)
channels that causes rapid depolarisation which results in action potential.
 The pace maker cells repolarise slowly via K+ efflux.

21. What is lymph? Write its function.

 The fluid inside the lymphatics is called lymph.
 It contain large number of lymphocytic cells

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 The lymph nodes that filter the lymph from the lymphatic vessels of the
skin are highly concentrated in the neck.
 The lymph nodes successfully prevent the invading microorganisms from
reaching the blood stream.
 Lymph collects fluids from your tissues and returns them to your blood. It
carries nutrients and proteins to your cells and tissues
 Fats are absorbed through lymph in the lacteals present in the villi.

22. What are the heart sounds? When and how are these sounds produced?
 During each cardiac cycle two sounds (lub-dub) are produced.
 The first heart sound (lub) is associated with the closure of the tricuspid and
bicuspid valves whereas second heart sound (dub) is associated with the
closure of the semilunar valves.

23. Select the correct biological term.

 Disc shaped cells which are concave on both sides- Erythrocytes
 Most of these have a large, bilobed nucleus- Leucocytes
 Enable red cells to transport blood- Haemoglobin
 The liquid part of the blood- Plasma
 Most of them move and change shape like an amoeba- Phagocyte
 Consists of water and important dissolved substances- Plasma
 Destroyed in the liver and spleen after circulating in the blood for four
months- Erythrocytes
 The substances which gives red cells their colour- Haemoglobin
 Another name for red blood cells- Erythrocytes
 Blood that has been changed to a jelly- Blood clot.
 A word that means cell eater- Phagocyte
 Cells without nucleus- Erythrocytes/Platelets
 White cells made in the lymphatic tissue- Lymphocytes
 Blocks wound and prevent excessive bleeding- Blood clot
 Fragment of cells which are made in the bone marrow- Platelets
 Another name for white blood cells- Leucocytes
 Slowly releases oxygen to blood cells- Haemoglobin
 Their function is to help blood clot in wounds- Platelets

24. Name and Label the given diagrams to show A, B, C, D, E, F, and G

A-Aorta B-Left pulmonary artery C- Left pulmonary vein
D-Semilunar valve E-Left ventricle F- Right ventricle
G-Inferior venacava
Chapter-8
Excreation
13. Arrange the following structures in the order that a drop of water
entering the nephron would encounter them.
(a) Afferent arteriole
(e) Glomerulus
(b) Bowman's capsule
(g) Proximal tubule
(f) Loop of Henle

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(d) Distal tubule

(c) Collecting duct
(h) Renal pelvis

14.Name the three filtration barriers that solutes must come across as they
move from plasma to the lumen of Bowman’s capsule. What components
of the blood are usually excluded by these layers?
 Glomerular capillary endothelium.
 Basal lamina or basement membrane.
 Epithelium of Bowman's capsule.
 Blood corpuscles and plasma protein are excluded by these layers.

15.What forces promote glomerular filtration? What forces opposes them?

What is meant by net filtration pressure?
 The glomerular blood pressure promote glomerular filtration (approximately
55 mmHg)
 Two opposing forces-Colloidal osmotic pressure (30 mmHg) and the
Capsular hydrostatic pressure (15 mmHg)
 Net filtration pressure = 55 mmHg -(30 mmHg + 15 mHg)=10mmHg

16.Identify the following structures and explain their significance in renal

physiology?
a. Juxtaglomerular apparatus
 Juxta glomerular apparatus (JGA) is a specialized tissue in the afferent
arteriole of the nephron that consists of macula densa and granular cells.
 The macula densa cells sense distal tubular flow and affect afferent arteriole
diameter, whereas the granular cells secrete an enzyme called renin.
 A fall in glomerular blood flow granular cells to release renin to increase
blood preasure.
b. Podocytes
 The external parietal layer of the Bowman's capsule is made up of simple
squamous epithelium and the visceral layer is made of epithelial cells
called podocytes.
 The podocytes end in foot processes which cling to the basement
membrane of the glomerulus.
 The openings between the foot processes are called filtration slits.
c. Sphincters in the bladder
Internal sphincter
 Located at the base of the bladder, this sphincter is made of smooth muscle
and is under involuntary control.
External sphincter
 Located lower down the urethra, this sphincter is made of striated muscle
and is under voluntary control.

17. In which segment of the nephron most of the re-absorption of

substances takes place?
 The proximal convoluted tubule (PCT) of the nephron .

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18. When a molecule or ion is reabsorbed from the lumen of the nephron,
where does it go? If a solute is filtered and not reabsorbed from the
tubule, where does it go?
 When a molecule or ion is reabsorbed from the lumen of the nephron, it goes
into the bloodstream through the peritubular capillaries and systemic
venous circulation.
 If a solute is filtered and not reabsorbed from the tubule, it goes along with
urine.

19. Which segment is the site of secretion and regulated reabsorption of

ions and pH homeostasis?
 The distal convoluted tubule is the segment of the nephron that regulates
reabsorption and secretion of ions and PH homeostasis.
 In this segment, the concentrations of sodium, potassium, and other
electrolytes are adjusted, along with the pH of the tubular fluid.

20. What solute is normally present in the body to estimate GFR in

humans?
 Creatinine is the solute that is normally present in the body to estimate
glomerular filtration rate (GFR) in humans.

21. Which part of the autonomic nervous system is involved in micturition

process?
 The parasympathetic nervous system is the part of the autonomic nervous
system that is involved in the micturition process.

22. If the afferent arteriole of the nephron constricts, what happens to the
GFR in that nephron? If the efferent arteriole constricts what happens to
the GFR in that nephron?
 If the afferent arteriole of a nephron constricts, the glomerular filtration rate
(GFR) decreases.
 If the efferent arteriole constricts, the GFR increases

23.Identfiy the biological term

 A liquid which gathers in the bladder- Urine
 Produced when blood is filtered in a Bowman’s capsule- Glomerular filtrate
 Temporary storage of urine- Urinary bladder
 A ball of inter twined capillaries- Glomerulus
 Removal of unwanted substances from the body- Excretion
 Each contains a glomerulus- Bowman’s capsule
 Carry urine from the kidneys to the bladder- Ureters
 Scientific term for urination- Micturition
 Regulation of water and dissolved substances in blood and tissue fluid-
Osmosis
 Consists of the kidneys, ureters and bladder- Urinary system
 Removal of useful substances from glomerular filtrate-Reabsorption.
 What solute the blood contains that are not present in the glomerular filtrate-
Proteins.

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24. With regards to toxicity and the need for dilution in water, how different
are ureotelic and uricotelic excretions? Give examples of animals that
use these types of excretion?

 Ureotelic and uricotelic animals differ in the toxicity of their excretions and
the amount of water needed to dilute them.
 Ureotelic-These animals excrete urea, which is less toxic and requires less
water than ammonia or uric acid. Examples include mammals, some bony
fish, and adult amphibians.
 Uricotelic-These animals excrete uric acid, which is the least toxic and
requires the least water. Examples include birds, snakes, lizards, and
terrestrial arthropods like insects.

25. Differentiate protonephridia from metanephridia

Protonephridia Metanephridia
1.It is a simple tubular excretory organ 1.It is a tubular excretory
seen in phyla like –Platyhelminthes, organ seen in phyla like –
Nematodes and Chordata (Amphioxus). Arthropoda (Insects),
Annelida and Mollusca.
2.They have either Flame cells 2.They have either
(Platyhelminthes),Solenocytes Malpighian tubules
(Amphioxus) and Rennette cells (Insects) and Green glands
(Nematodes). (Prawns).
26.What is the nitrogenous waste produced by amphibian larvae and by the
adult animal?
1) Amphibian larvae-Ammonia 2) Adult Amphibian-Urea

27. How is urea formed in the human body?

 The nitrogenous waste formed as a result of breakdown of amino acids is
converted to urea in the liver by the Ornithine cycle or urea cycle.

28. Differentiate cortical from medullary nephrons.

Cortical nephrons Juxta medullary nephrons
Loop of Henle is too short and Very long loop of Henle that run
extends only very little into the deep into the renal medulla.
renal medulla.
It produce dilute urine It produce concentrated urine

29. What vessels carry blood to the kidneys? Is this blood arterial or
venous?
 The renal arteries carry arterial blood to the kidneys.

30. Which vessels drain filtered blood from the kidneys?

 The renal vein is the blood vessel that drains filtered blood from the kidneys.

31. What is tubular secretion? Name the substances secreted through the
renal tubules.
 Tubular secretion- Substances such as H+, K+, NH4+, creatinine and
organic acids move into the DCT from the peritubular capillaries.

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32. How are the kidneys involved in controlling blood volume? How is the
volume of blood in the body related to arterial pressure?
 The kidneys are the primary organ responsible for regulating blood volume
by controlling the amount of water and solutes in the blood.
 The kidneys do this through filtration, reabsorption, and secretion.
 The kidneys also produce erythropoietin, which signals the bone marrow
to produce red blood cells.
 The volume of blood in the body is directly related to arterial pressure,
with an increase in blood volume leading to an increase in arterial
pressure.

33.Name the three main hormones involved in the regulation of the renal
function?
 Aldosterone, antidiuretic hormone (ADH) and atrial natriuretic factor (ANF)

34.What is the function of anti diuretic hormone? Where is it produced and

what stimuli increases or decreases its secretion?
 It regulates the body's water and salt levels, blood pressure and urine
production.
 The ADH is produced by hypothalamus and released into the blood stream
by the posterior pituitary.
 ADH secretion is triggered by Blood volume changes, Blood osmolarity,
Thirst, nausea, vomiting, and pain.
 Excess fluid intake prevents the release of ADH, which can lead to
increased urine production.

35.What is the effect of aldosterone on kidneys and where is it produced?

 Na+ reabsorption , K+excretion, Water reabsorption and Blood pressure
regulation.
 Aldosterone is produced in the adrenal cortex of zona glomerulosa.

36.Explain the heart’s role in secreting a hormone that regulates renal

function? What hormone is this?
 Atrial natriuretic factor (ANF) is a peptide hormone produced by atrial
muscle cells of the heart.
 It increases Na+ excretion and increases the blood flow to the glomerulus,
acting on the afferent glomerular arterioles as a vasodilator.
 It decreases aldosterone release from the adrenal cortex and also decreases
release of renin.
 ANF acts antagonistically to the renin- angiotensin system.

Chapter -9
Locomotion and Movement
21. Name the different types of movement.
 Amoeboid movement, ciliary movement, flagellar movement and muscular
movement.

22. Name the filaments present in the sarcomere.

 The two main filaments present in a sarcomere are actin and myosin.

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23. Name the contractile proteins present in the skeletal muscle.

 Contractile proteins- Actin and Myosin.
 Regulatory proteins -Tropomyosin and Troponin.

24.When describing a skeletal muscle, what does “striated” mean?

 Along the length of each myofibril there are a repeated series of dark and
light bands.
 The dark A-bands (Anisotropic bands) and the light I-bands (Isotropic
bands) are perfectly aligned with one another. This type of arrangement gives
the cell a striated appearance.

25.How does an isotonic contraction take place?

 In isotonic contraction the length of the muscle changes but the tension
remains constant.
 Here, the force produced is unchanged. Example: lifting dumb bells and
weightlifting.

26. How does an isometric contraction take place?

 In isometric contraction the length of the muscle does not change but the
tension of the muscle changes.
 Here, the force produced is changed. Example: pushing against a wall,
holding a heavy bag.

27. Name the bones of the skull.

 There are 29 bones present in the human skull. These includes 8 cranial
bones, 14 facial bones, one hyoid bone and 6 auditory bones.
 Cranial bones are paired parietal, paired temporal and individual bones
such as the frontal, sphenoid, occipital and ethmoid.
 Facial bones such as maxilla, zygomatic, palatine, inferior nasal concha,
lacrimal and nasal bones are paired and individual bones such as the
mandible and vomer.
 Each middle ear contains three tiny bones- malleus, incus and stapes
collectively are called ear ossicles.

28. Which is the only joint less bone in human body?

 The hyoid bone.

29. List the three main parts of the axial skeleton?

 Skull, vertebral column, and thoracic cage

30. How is tetany caused?

 Rapid muscle spasms occur in the muscles due to deficiency of parathyroid
hormone resulting in reduced calcium levels in the body.

31. What are the functions of the skeletal system?

 Support –It forms a rigid framework and supports the weight of the body
against gravity.
 Shape - It provides and maintains the shape of the body.
 Protection – It protects the delicate internal organs of the body.

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 Acts as reservoir – It stores minerals such as calcium and phosphate.

 Locomotion -It acts as lever along with the muscles attached to it.
 Strength-It can withstand heavy weight and absorbs mechanical shock.
 As a haemopoietic tissue – Red and White blood cells are produced in the
bone marrow of the ribs, spongy bones of vertebrae and extremities of
long bones.

32. What are the different types of rib bones that form the rib cage?
 The first seven pairs of ribs are called ‘true ribs’ it attached to sternum.
 The 8th, 9th and 10th pairs of ribs do not articulate directly with the
sternum but joined with the cartilaginous part of the seventh rib. These are
called ‘false ribs’
 The last 11th and 12th pairs of ribs are not connected ventrally. Therefore,
they are called as ‘floating ribs’

33. What are the bones that make the pelvic girdle?
 Ilium, ischium, and pubis

34. List the disorders of the muscular system.

1.Myasthenia Gravis
 An autoimmune disorder affecting the action of acetylcholine at neuro-
muscular junction leading to fatigue, weakening and paralysis of skeletal
muscles
 Acetylcholine receptors on the sarcolemma are blocked by antibodies
leading to weakness of muscles.
 It can make chewing, swallowing, talking and even breathing difficult
2.Tetany
 Rapid muscle spasms occur in the muscles due to deficiency of parathyroid
hormone resulting in reduced calcium levels in the body.
3.Muscle Fatigue
 Muscle fatigue is the inability of a muscle to contract after repeated muscle
contractions.
 This is due to lack of ATP and accumulation of lactic acid by anaerobic
breakdown of glucose
4.Atrophy
 A decline of muscular activity results in the condition called atrophy which
results in the reduction in the size of the muscle and makes the muscle to
become weak, which occurs with lack of usage as in chronic bedridden
patients.
5.Muscle Pull
 Muscle pull is actually a muscle tear. A traumatic pulling of the fibres
produces a tear known as sprain.
 This can occur due to sudden stretching of muscle beyond the point of
elasticity.
 Back pain is a common problem caused by muscle pull due to improper
posture with static sitting for long hours.
6.Muscular Dystrophy
 Progressive degeneration and weakening of skeletal muscle fibres, leading
to death.

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 The most common form of muscular dystrophy is called Duchene Muscular

Dystrophy (DMD).

35. Explain the sliding- filament theory of muscle contraction.

 In 1954, Andrew F. Huxley and Rolf Niedergerke proposed the sliding-
filament theory to explain muscle contraction.
 Overlapping actin and myosin filaments of fixed length slide past one
another in an energy requiring process, resulting in muscle contraction.
 Muscle contraction is initiated by the signal from CNS.
 Release of acetylcholine at the neuromuscular junction
 Causes action potential in muscle fibre.
 The action potential travels along the T-tubules and triggers the release of
calcium ions from sarcoplasmic reticulum.
 Calcium ions combine with troponin and tropomyosin uncovers the binding
sites on actin and initiates contraction.
 Myosin binding sites on actin exposed. Myosin head binds to actin to form
cross bridge.
 Myosin head executes power stroke (90◦ to 45‫)ﹾ‬.
 Actin filament slides towards the centre of sarcomere (contraction)
 Signal from CNS stops; calcium ions are pumped back into the
sarcoplasmic reticulum.
 Tropomyosin masks the binding sites on actin. Filaments pulled back to the
original position (relaxation)

36. What are the benefits of regular exercise?

 The muscles used in exercise grow larger and stronger.
 The resting heart rate goes down.
 More enzymes are synthesized in the muscle fiber.
 Ligaments and tendons become stronger.
 Joints become more flexible. Protection from heart attack.
 Influences hormonal activity. Improves cognitive functions.
 Prevents Obesity. Promotes confidence and esteem.
 Aesthetically better with good physique.
 Over all well-being with good quality of life.
 Prevents depression, stress and anxiety.

Chapter -10
Neural Control And Coordination

15. Why is the blind spot called so?

 The optic nerves and the retinal blood vessels enter the eye slightly below
the posterior pole.
 Which is devoid of photo receptors; hence this region is called blind spot.

16. Sam’s optometrist tells him that his intraocular pressure is high. What
is this condition called and which fluid does it involve?
 Glaucoma - Aqueous humour

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17. The action potential occurs in response to a threshold stimulus; but not
at sub threshold stimuli. What is the name of the principle involved?
 All-or-none principle.

18. Pleasant smell of food urged Ravi to rush into the kitchen. Name the
parts of the brain involved in the identification of food and emotional
responses to odour.
 The hypothalamus contains a pair of small rounded body called
mammillary bodies that are involved in olfactory reflexes and emotional
responses to odour.

19. Cornea transplant in humans is almost never rejected. State the reason.
 Cornea does not have blood vessels.

20. At the end of repolarization, the nerve membrane gets hyperpolarized.

Why?
 Because the membrane potential becomes more negative than the resting
potential.
 During this, K+ ion gates are more permeable to K+ even after reaching the
threshold level as it closes slowly,hence called Lazy gates.

21. The choroid plexus secretes cerebrospinal fluid. List the function of it.
 CSF provides buoyancy to the CNS structures
 CSF acts as a shock absorber for the brain and spinal cord.
 It nourishes the brain cells by transporting constant supply of food and
oxygen.
 It carries harmful metabolic wastes from the brain to the blood and
maintains a constant pressure inside the cranial vessels.

22. What is ANS? Explain the components of ANS.

 Autonomic Neural System-A part of the peripheral nervous system that
controls involuntary bodily functions, such as heart rate, digestion, and
respiration.ANS controlling centre is in the hypothalamus.
Components of ANS
 Preganglionic neuron whose cell body is in the brain or spinal cord; its
myelinated axon exits the CNS as part of cranial or spinal nerve and ends in
an autonomic ganglion.
 Autonomic ganglion consists of axon of pre ganglionic neuron and cell bodies
of postganglionic neuron.
 Postganglionic neuron conveys nerve impulses from autonomic ganglia to
visceral effector organs.
 The autonomic neural system consists of Sympathetic neural system and
Parasympathetic neural system.

23.Why the limbic system is called the emotional brain? Name the parts of
it.
 It plays a primary role in the regulation of pleasure, pain, anger, fear, sexual
feeling and affection. The hippocampus and amygdala also play a role in
memory.

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 The main components of limbic system are olfactory bulbs, cingulate gyrus,
mammillary body,amygdala, hippocampus and hypothalamus.

24. Classify receptors based on type of stimuli.

Receptors Stimulus Effector organs
Pressure and Cochlea of the inner ear and the
1)Mechano receptors
vibration semi circular canal and utriculus.
Taste buds in the tongue and
2)Chemoreceptors Chemicals
nasal epithelium
3)Thermoreceptors Temperature Skin
Rod and cone cells of the retina in
4)Photoreceptors Light
the eye
25. Differentiate between rod and cone cells.
Rod cells Cone cells
1)Rods are responsible for vision in The cones are responsible for
dim light colour vision and works best in
the bright light.
2)The pigment present in the rods The pigment present in the cones
is rhodopsin, formed of a protein is photopsin, formed of opsin
scotopsin and retinal (an protein and retinal.
aldehyde of vitamin A )
3)There are about 120 millions rod There may be 6-7 millions cone
cells cells
4)Rods are predominant in the Cones are concentrated in the
extra fovea region fovea region
26. The sense of taste is considered to be the most pleasurable of all senses.
Describe the structure of the receptor involved with a diagram.
 Gustatory receptor: The tongue is provided with many small projections
called papillae which give the tongue an
abrasive feel.
 Taste buds are located mainly on the
papillae which are scattered
over the entire tongue surface few are
scattered on the soft palate, inner
surface of the cheeks, pharynx and
epiglottis of the larynx.
 Taste buds are flask-shaped and
consist of 50 – 100 epithelial cells of
two major types.
 Gustatory epithelial cells (taste cells)
and Basal epithelial cells (Repairing
cells)
 Gustatory hairs are the sensitive portion of the gustatory cells bathed by
saliva and they have sensory dendrites which send the signal to the brain.
 The basal cells that act as stem cells, divide and differentiate into new
gustatory cells.

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27. Describe the sensory receptors present in the skin.

 Tactile merkel disc is light touch receptor lying in the deeper layer of
epidermis.
 Hair follicle receptors are light touch receptors lying around the hair
follicles.
 Meissner’s corpuscles are small light pressure receptors found just beneath
the epidermis in the dermal papillae.
 Pacinian corpuscles are the large egg shaped receptors found scattered deep
in the dermis and monitoring vibration due to pressure.
 Ruffini endings which lie in the dermis responds to continuous pressure.
 Krause end bulbs are thermoreceptors that sense temperature.

Chapter -11
Chemical Coordination and Integration
14. Comment on homeostasis.
 Maintenance of constant internal environment of the body by the different
coordinating system.

15. Hormones are known as chemical messenger. Justify.

 Hormones are chemical messengers because they act as organic catalysts
and coenzymes to perform specific functions in the target organs.

16. Write the role of oestrogen in ovulation.

 Oestrogen is responsible for the maturation of reproductive organs and the
development of secondary sexual characters at puberty.
 When the level of Oestrogen is sufficiently high, it produces a sudden
release of LH, usually around day thirteen of the cycle.

17. Comment on Acini of thyroid gland.

 The lobules of thyroid gland consist of follicles called acini.
 Each acinus is lined with glandular, cuboidal epithelial cells.
 The lumen of acinus is filled with colloid, a thick glycoprotein mixture
consisting of thyroglobulin molecules.

18. Write the causes for diabetes mellitus and diabetes insipidus.
Diabetes mellitus Diabetes insipidus
It is caused due to reduced It is caused due to hyposecretion of
secretion of insulin. As the result, antidiuritic hormone(vasopressin)
blood glucose level is elevated
.
Symptoms- Polyurea, Polyphagia, Symptoms- frequent urination
Polydipsia, Ketosis (breakdown of (polyurea) and excessive consumption
fat into glucose results in of liquids due to thirst (polydipsia).
accumulation of ketone bodies) in
blood.

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19. Specify the symptoms of acromegaly

 Over growth of hand bones, feet bones, jaw bones, malfunctioning of gonads,
enlargement of viscera, tongue, lungs, heart, liver, spleen and endocrine gland
like thyroid, adrenal etc.

20. Write the symptoms of cretinism.

 Retarded skeletal growth, absence of sexual
maturity, retarded mental ability, thick wrinkled
skin, protruded enlarged tongue, bloated face,
thick and short limbs occurs, low BMR, slow pulse
rate, subnormal body temperature and elevated
blood cholesterol.
21. Briefly explain the structure of thyroid gland.

 The butterfly shaped thyroid gland is a bilobed

gland located below the larynx on each side of
upper trachea.
 It is the largest endocrine gland in the body. Its
two lateral lobes are connected by a median tissue
mass called isthmus.
 Each lobe is made up of many lobules .The lobules consist of follicles called
acini .Each acinus is lined with glandular, cuboidal or squamous epithelial
cells.
 The lumen of acinus is filled with colloid, a thick glycoprotein mixture
consisting of thyroglobulin molecules.

22. Name the layers of adrenal cortex and mention their secretions.
 Zona glomerulosa- Mineralocorticoids(Aldosterone)
 Zona fasciculata- Glucocorticoids (cortisol,corticosterone)
 Zona reticularis- Adrenal androgen,oestrogen and glucocorticoids.

23. Differentiate hyperglycemia from hypoglycemia

Hyperglycemia Hypoglycemia
1)Blood sugar levels are too high 1)Blood sugar levels are low.
2)It is caused due to reduced 2)Hypoglycaemia is due to increased
secretion of insulin. secretion of insulin there by blood
glucose level decreases.
3) Symptoms-polyurea (excessive 3)Increased heartbeat, weakness,
urination), polyphagia (excessive intake nervousness, headache, confusion, lack
of food), polydipsia (excessive of co-ordination, slurred speech, serious
consumption liquids due to thirst), brain defects like epilepsy and coma occurs.
ketosis (breakdown of fat into glucose
results in accumulation of ketone
bodies) in blood.

24 Write the functions of (CCK) Cholecystokinin.

 Cholecystokinin (CCK) is secreted by duodenum in response to the presence
of fat and acid in the diet.

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 It acts on the gall bladder to contract and release of bile into duodenum and
stimulates the secretion of pancreatic enzymes and its discharge.

25. Growth hormone is important for normal growth. Justify the statement.
Growth hormone (somatotropic hormone)
 It is a peptide hormone. Growth hormone promotes growth of all the tissues
and metabolic process of the body.
 It influences the metabolism of carbohydrates, proteins and lipids and
increases the rate of protein biosynthesis in the cells.
 It stimulates chondrogenesis (cartilage formation), osteogenesis (bone
formation) and helps in the retention of minerals like nitrogen, potassium,
phosphorus, sodium etc., in the body.
 GH increases the release of fatty acid from adipose tissue and decreases the rate
of glucose utilization for energy by the cells.
 Thus it conserves glucose for glucose dependent tissues, such as the brain.

26. Pineal gland is an endocrine gland, write its role.

 It secretes the hormone, melatonin, which plays a central role in the regulation
of circadian rhythm of our body and maintains the normal sleep wake cycle.
 It also regulates the timing of sexual maturation of gonads.
 In addition melatonin also influences metabolism, pigmentation, menstrual
cycle and defence mechanism of our body.

27. Comment on the functions of adrenalin.

 "3F hormone" (fight, flight and fright hormone).
 Adrenalin increases liver glycogen breakdown into glucose and increases the
release of fatty acids from fat cells.
 During emergency it increases heart beat rate and blood pressure.
 It stimulates the smooth muscles of cutaneous and visceral arteries to decrease
blood flow.
 It increases blood flow to the skeletal muscles thereby increases the
metabolic rate of skeletal muscles, cardiac muscles and nervous tissue.

28. Predict the effects of removal of pancreas from the human body.
 Digestion and maintenance of blood sugar level get affected.
 Pancreas secretes digestive enzymes and hormones like insulin and glucogon.
 The digestive enzymes digest carbohydrates, proteins, and fats.
 Insulin and glucagon regulate blood sugar levels

29. Enumerate the role of kidney as an endocrine gland.

 In kidneys, hormones such as renin, erythropoietin and calcitriol are
secreted.
 Renin is secreted by juxta glomerular cells (JGA), which increases blood
pressure when angiotensin is formed in blood.
 Erythropoietin is also secreted by the JGA cells of the kidney and stimulates
erythropoiesis (formation of RBC) in bone marrow.
 Calcitriol is sercreted by proximal tubules of nephron. It is an active form of
vitamin D3 which promotes calcium and phosphorus absorption from intestine
and accelerates bone formation.

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30. Write a detailed account of gastro intestinal tract hormones.

 Group of specialized endocrine cells present in gastro-intestinal tract secretes
hormones such as gastrin, cholecystokinin (CCK), secretin and gastric
inhibitory peptides (GIP).
 Gastrin acts on the gastric glands and stimulates the secretion of HCl and
pepsinogen.
 Cholecystokinin (CCK) is secreted by duodenum in response to the presence of
fat and acid in the diet. It acts on the gall bladder to release bile into
duodenum and stimulates the secretion of pancreatic enzymes and its
discharge.
 Secretin acts on acini cells of pancreas to secrete bicarbonate ions and water
to neutralize the acidity.
 Gastric inhibitory peptide (GIP) inhibits gastric secretion and motility.

Chapter -12
Trends in Economic Zoology
14.Polyculture of fishes is highly advantageous. Discuss.
 Fishes proposed for polyculture should be able to live together without
interfering or attacking other fishes.
 In this culture the upper layer fishes feeds on phyto and zooplanktons the
middle layer fishes feeds on submerged plants and fishes lives in the deeper
layers feeds on bottom dwellers debris of plants and animals.

15. Write the advantages of vermicomposting

 Vermicompost is rich in essential plant nutrients.
 Improves soil structure texture, aeration, and water holding capacity and
prevents soil erosion
 Eco-friendly to soil for farming and terrace gardening.
 It enhances seed germination and ensures good plant growth

16. Name the three castes in a honey bee colony.

 Queen bee, worker bee and drones (male bees).

17. Name the following:

 The largest bee in the colony- Queen bee
 The kind of flight which the new virgin queen takes along with the drones out
of the hive- Nuptial flight

18. What are the main duties of a worker bee?

 Secretion of royal jelly, prepares bee-bread to feed the larvae, feeds the
queen, takes care of the queen and drones, secretes bees wax, builds
combs, cleans and fans the bee hive.
 Then she becomes a soldier and guards the bee hive. In the second half her
life lasting for three weeks, she searches and gathers the pollen, nectar,
propolis and water.

19. What happens to the drones after mating flight?

 Drones dies after copulation with virgin queen.

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20. Give the economic importance of Silkworm.

 Silk fibers are utilized in preparing silk clothes.
 Silk fibers are now combined with other natural or synthetic fibers to
manufacture Teri-Silk, Cot-Silk etc.
 Silk is dyed and printed to prepare ornamented fabrics
 Silk is used in industries and for military purposes.
 It is used in the manufacture of fishing fibers, parachutes, insulation coils
for telephone, tyres of racing cars, in medical dressings and as suture
materials.

21. What are the Nutritive values of fishes?

 Fishes from a rich source of protein food.
 Fish species such as sardines, mackerel, tuna, herrings have high amino
acids concentrations particularly histidine.
 It is rich in fat such as omega 3 fatty acids.
 Minerals such as calcium, magnesium, phosphorus, potassium, iron,
manganese, iodine and copper.

22. Give the economic importance of prawn fishery.

 Prawn flesh is palatable and rich in glycogen, protein with low fat content.
 Helps to earn a suitable amount of foreign exchange.

23. Give the economic importance of lac insect.

 Lac is largely used as a sealing wax and adhesive for optical instruments. It
is used in electric industry, as it is a good insulator.
 It is used in preparations of shoe and leather polishes and as a protective
coating of wood.
 It is used in laminating paper board, photographs, engraved materials and
plastic moulded articles.
 Used as a filling material for gold ornaments

24. Name any two trees on which lac insect grows.

 Karanagalli , Karuvelai and Kumbadiri.

25. Define cross breeding.

 Breeding between a superior male of one breed with a superior female of
another breed.
 The cross bred progeny has superior traits ( hybrid vigour or heterosis).

26. What are the advantages of artificial insemination?

 It increases the rate of conception
 It avoids genital diseases
 Semen can be collected from injured bulls which have desirable traits.
 Superior animals located apart can be bred successfully.

27. Discuss the various techniques adopted in cattle breeding?

1.Inbreeding
 Breeding between animals of the same breed for 4-6 generations is called
inbreeding.
 It increases homozygosity and exposes the harmful recessive genes.
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 Continuous inbreeding reduces fertility and even productivity, resulting in

“inbreeding depression”.
2.Outbreeding:
 The breeding between unrelated animals is called outbreeding.
 Individuals produced do not have common ancestors for 4-6 generations.
 Outbreeding helps to produce new and favourable traits, to produce hybrids
with superior qualities and helps to create new breeds.
i.Out crossing:
 It is the breeding between unrelated animals of the same breed but having
no common ancestry.
 This method is suitable for breeding animals below average in productivity.
ii.Cross breeding:
 Breeding between a superior male of one breed with a superior female of
another breed. The cross bred progeny has superior traits ( hybrid vigour or
heterosis).
iii.Interspecific hybridization:
 In this method of breeding mating is between male and female of two
different species.
 The progeny obtained from such crosses are different from their parents,
and may possess the desirable traits of the parents.
 Mule was produced by the process of inter specific hybridization between a
male donkey and a female horse.
3.Artificial insemination:
 Artificial insemination is a technique in which the semen collected from the
male is injected to the reproductive tract of the selected female.
 Artificial insemination is economical measure where fewer bulls are required
and maximum use can be made of the best sire.
4.Multiple ovulation embryo transfer technology (MOET)
 It is another method of propagation of animals with desirable traits. This
method is applied when the success rate of crossing is low even after artificial
insemination.
 In this method Follicle stimulating hormone (FSH) is administered to cows
for inducing follicular maturation and super ovulation. Instead of one egg per
cycle, 6-8 eggs can be produced by this technology. The eggs are carefully
recovered non-surgically from the genetic mother and fertilized artificially.
 The embryos at 8-32 celled stages are recovered and transferred to a
surrogate mother. For another round of ovulation, the same genetic mother is
utilized. This technology can be applied to cattle, sheep and buffaloes.

28. Mention the advantages of MOET.

 To produce high milk yielding females cows and high-quality meat yielding
bulls in a short time.

29. Write the peculiar characters of duck.

 The body is fully covered with oily feathers.
 They have a layer of fat under their skin which prevents it from getting wet.
 They lay eggs at night or in the morning.
 The ducks feed on rice bran, kitchen wastes, waste fish and snails.

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30. Explain the life cycle of bombyx mori.

 The adult of Bombyx mori is about 2.5 cm in length and pale creamy white in
colour, flight is not possible by the female moth.
 Unisexual and does not feed during its very short life period of 2-3 days.
 Just after emergence, male moth copulates with female for about 2-3 hours.
 A single female moth lays 400 to 500 eggs depending upon the climatic
conditions.
 The eggs after ten days of incubation hatch into larva called as caterpillar.
 The newly hatched caterpillar is about 3 mm in length and is pale,
yellowish-white in colour and feed on the mulberry leaves.
 After 1st, 2nd, 3rd and 4th moultings caterpillars get transformed into 2nd,
3rd, 4th and 5th instars respectively
 It takes about 21 to 25 days after hatching. The fully grown caterpillar is 7.5
cm in length.
 It develops salivary glands, stops feeding and undergoes pupation.
 It secretes a sticky fluid through their silk gland. The secreted fluid comes
out through spinneret form of long fine thread of silk which form cocoon.
 The length of continuous thread secreted by a caterpillar for the formation of
cocoon is about 1000-1200 metres which requires 3 days to complete.
 The pupal period lasts for 10 to 12 days and the pupae cut through the
cocoon and emerge into adult moth.

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ERRORLESS MATERIAL
11th- BIO-ZOOLOGY
ANSWERS FOR BOOK BACK MCQ’s
2025-26
1-The Living World
1. d. All the above 3. a. Collagen
2. b. Taxon 4. a. Tight junction
3. a. Taxon 5. b. Brown fat
4. d. Insecta
4-Organ and Organ Systems in
5. d. Monograph Animals
6. a. Walter Rosen
1. b. Segments 14 – 17
7. b. Evolutionary and Phylogenetic
8. a. DNA and RNA 2. b. Hermaphroditic but not self -
fertilizing
2-Kingdom Animalia 3. b. False
1. a. Radial 4. a. One pair, sessile compound
2. c. Coelenterata and kidney shaped
3. b. Flame cells 5. a. At the junction of mid gut and
4. d. Liver fluke hind gut, about 150.
5. b. Flame cells of Planaria 6. c. Mosaic
7. a. 10, 10
6. b. Pheretima
7. a. Annelida 8. d. Cockroach
8. c. circular, longitudinal muscles 9. d. stops when mouth is opened.
and setae 10. c. Mesonephros
9. a. Insects
11 d. frogs evolved from gilled
10. a. Prawn ancestor
11 d. None of the above
12. c. Muscular layer in the body
12. c. Arthropoda wall of earthworm is made up of
13. d. Fish circular muscles only.
14. a. Icthyophis
13. a. Antennae, compound eyes,
15. d. Crocodile maxillary palps, anal cerci
16. d. Whale – Ammonotelic
17. c. Ornithorhynchus
5-Digestion and Absorption
18. b. Aves
1. d. Enterokinase stimulates the
19. b. p – (iii), q – (iv), r – (ii), s – (i)
secretion of pancreatic juice.
20. b. Echinodermata
2 c. The process of preparation of
21. a. Physalia – Portugese man of incompletely digested acidic
war food through gastric juice.
3. c. Cholecystokinin and secretin
3-Tissue Level of Organisation 4. a. Hepatopancreatic duct
1. d. Both (b) and (c) 5. d. All the above
2. d. Trachea 6. b. Renin – liver
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 34

7. a. Lymph vessels within villi 9. c. The total surface area of the

8. a. Emulsification capillaries is larger than the total
9. b. Trypsinogen into trypsin surface area of the arterioles.
10 a. Bilirubin and biliverdin 10. d. O -ve
(i) intestinal juice 11. d. Active transport
11. a. ( P-iv ) ( Q -iii ) ( R- i ) ( S – ii ) 12. a. Greater than the hydrostatic
12. b. ( P-ii ) ( Q -iv ) ( R- i ) ( S – iii ) pressure
13. c.( P-iv ) ( Q -iii ) ( R- ii ) ( S – i ) 13. c. 150
14. a. Production of insulin 14. b. presence of valves
15. d. A is false but B is true 8-Excretion
16. d. They only participate in 1. b. Length of Henle’s loop
digestion of fats. 2. d. The urine will be more dilute
6-Respiration 3. b. Urine will be continue to
1. b. medulla oblongata
2 . c. ribs collect normally in the bladder
3. a. tracheal tubes 4. c. urea
4. a. inflammation of bronchus and 5. b. DCT - Absorption of glucose
bronchioles.
6. b. Inner wall of Bowman’s
5. a. sigmoid
capsule
6. c. 500 mL
7. a. Blood without blood cells and
7. d. contracts and flattens
proteins
8. c. carbamino haemoglobin 8. d. calcium oxalate
9. c. residual volume
10. d. TV + IRV + ERV 9. b. uricotelic
11. c. less CO2 in the blood 10. a. Aquaphorins
12. a. carbon monoxide and 11. c. antidiuretic hormone
carcinogens
13. b. P = iii, Q = i, R = ii 12. c. haemolymph
14 c.Oxygen and carbon dioxide 9-Locomotion and Movement
diffuse down their concentration 1. b. mesoderm
gradients between blood and
alveolar air. 2. a. myocytes
15. (d) P – iii , Q – iv , R – i , S – ii 3. a. skeletal muscle
16. (a) P – ii , Q – iv , R – i , S – iii 4. a. tendon

7-Body Fluids and Circulation 5. b. fascicle

1. c. Bring interstitial fluid in blood 6. a. myoglobin
2. b. Fibrinogen 7. a. sarcomere
3. d. Bilirubin 8. a. myosin
4. c. Haemoglobin is absent
9. b. actin
5. c. Antigens on the surface of
10. a. sarcomere
RBC
6. c. AB 11. a. epimysium
7. a. Foetal RBCs 12. b. hinge joint
8 c. Closure of semi-lunar values 13. b. pivot joint
14. c. myosin

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15. d. freely movable joints. 8. a. Testosterone is produced by

16. a. Gout Leydig cells under the influence of
17. b. hip bone luteinizing hormone
9. b. Gigantism
18. a. girdles and their limbs
10. d. Deficiency of iodine in diet.
19. d. amoeboid
11. d. Hypophyseal portal system
20. c. olecranon process
12. d. Cortisol and aldosterone are
10-Neural Control and Coordination
steroid hormones
1 b. Organ of Corti
13. (d) (i) and (iii)
2. a. Sensory nerve – afferent
3. a. P = Acetylcholine, Q = Ca++ 12-Trends in Economic Zoology
4. c. Cell-B is concerned with 1. c. ii and iv is not correct
colour vision in bright light 2. c. Eudrillus
5. c. Assertion is true, but Reason 3. a) 1 – ii – IV
is false. 4. c. Attacus ricini
6. d. Hypothalamus 5. c. Assertion and reason is
7. a. Medulla oblongata correct but related
8. a. ( P-iv ),( Q-iii ),( R-i ),( S-ii 6. d. Apiculture
9. b. K+ 7. b. Inserts its proboscis into plant
10. d. A neuron is polarized only tissue suck juices and grows
when the outer surface of the c. Secretes lac from the hind end
axonal membrane possess a of body.
negative a charge and its inner 8. a. crustacea
surface is positively charged. 9. b. A combination of aquaculture
11. c. Increased energy output for and hydroponics
nerve impulse conduction
10. c. Raising and capturing fishes
12. b. (ii), (iii) and (iv) in fresh water
13. d. Its pathways always involve 11. c. Culture fishery
four neurons 12. b. Clearing of wines
14. b. Hyperpolarization 13. d. Ornamental breeds – Silkie
11-Chemical Coordination and
Integration
1. b. homeostasis
2 c. parathyroid and adrenal
3. b. insulin
4. a. Luteinising hormone
5. d. Thyroid and parathyroid
6. c. goitre
7. c. thymus

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