Solution

BIOLOGY TEST

Class 10 - Science
Section A
1. (a) Translocation
Explanation:
Translocation
2.
(d) nephrons
Explanation:
A nephron is a tissue, which is the basic structural and functional unit of the kidney. Its chief function is to regulate the
concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting
the rest as urine.

3.
(c) Jumping from a height
Explanation:
Jumping from a height

4.
(b) Nose
Explanation:
Nose

5.
(d) pollen grain
Explanation:
pollen grain

6.
(d) Seminal vesicle
Explanation:
Seminal vesicle

7. (a) round and green

Explanation:
Since roundness and green colour are shown by capital letters in the genotype so they are dominant traits. We know that only
dominant traits are expressed in F1 generation.

8.
(d) 3 : 1
Explanation:
All of the colours in F1 will be Vv (violet) when VV crosses with vv. When Vv crosses with Vv, the resulting F2 will contain
VV, Vv, vV, and vV, only one of which has white flowers while the others have violet ones. Ratio is thus 3 to 1.

9. (a) Ecosystem
Explanation:
All the interacting organisms of an area together with the non-living constituents form an ecosystem. An ecosystem consists of
biotic components comprising living organisms, as well as abiotic components comprising physical factors like rainfall, wind,
soil, and minerals.

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10.
(b) Paper
Explanation:
Substances that can be broken down by biological processes are said to be biodegradable. Substances like paper, wood and
cloth are biodegradable.

Section B
11. The systemic circulation provides the functional blood supply to all body tissue. It carries oxygen and nutrients to the cells and
picks up carbon dioxide and waste products. Systemic circulation carries oxygenated blood from the left ventricle, through the
arteries, to the capillaries in the tissues of the rest body. From the tissue capillaries, the deoxygenated blood returns through a
system of veins to the right atrium of the heart where again oxygenated process start.
12. Digestion of cellulose takes a longer time. Hence, herbivores need a longer small intestine to allow complete digestion of
cellulose. Carnivorous animals cannot digest cellulose, hence they have a shorter intestine.
13. Reflex action is a sudden/spontaneous/immediate action in response to the environment/stimulus e.g. sneezing.
Stimulus → Receptors (Nose) → Sensory neuron → Spinal cord → Motor neuron → Ef f ector → Response
(Muscles)
(Relay neuron)

14. Reasons for adopting contraceptive methods

1) To control population rise or birth rate.
2) Many sexually transmitted diseases can be passed on not using a contraceptive measure such as condom, copper-T, loop etc. To
prevent transmission of many of these diseases.
3) To prevent unwanted pregnancies.
15. i. The transfer of pollen grains from anther of a stamen to the stigma of a carpel is called pollination whereas fertilisation is the
process when the male gamete present in pollen grain joins the female gamete present in ovule.
ii. Pollination is an external mechanism whereas fertilisation is an internal mechanism which takes place inside the flower.
Site of fertilisation in flower is ovary.
Product of fertilisation in flower is zygote.
16. a. Violet flowers
Violet colour dominates over white colour of flowers.
b. 25%, It could not express itself in the presence of dominant gene/white colour is a recessive gene.
c. V V : V v
1:2
17. Ozone is formed in upper atmosphere by the reaction of ultraviolet UV radiations on oxygen O2 molecule. The damage to ozone
layer is a cause of concern to us as due to its damage more ultraviolet rays reach the earth's surface causing various health hazards.
Section C
18. i. Photosynthesis is a process by which green plants having chlorophyll can synthesize simple sugar (glucose) from water and
CO2 using the energy of sunlight. The light energy is used in a splitting of water molecules into hydrogen and oxygen (i.e.
chemical energy).
ii. Autotrophs: The organisms which can synthesize their own food from inorganic substances present in the environment are
called autotrophs. An autotroph or primary producer, is an organism that produces complex organic compounds , e.g. green
plants, autotrophic bacteria etc.
iii. Chloroplast: Chlorophyll is the green pigment capable of trapping light energy required during photosynthesis. This pigment
is present in the chloroplast of leaves of all green plants.
iv. Guard cells are present in the stomata under the leaves rim. Each stomatal pore is surrounded by a pair of guard cells, that
control their opening and closing by the inflow and outflow of water.
v. Heterotrophs: The organisms which cannot make their own food from inorganic substances and depend on other organisms
for their food are called heterotrophs, e.g. all animals, yeast, most bacteria, etc.
vi. Pepsin: It is a protein-digesting enzyme secreted from gastric glands present in the walls of the stomach, an enzyme in the
stomach that begins the digestion of proteins by splitting them into peptones (see peptidase). It is produced by the action of
hydrochloric acid on pepsinogen, which is secreted by the gastric glands.
19. A number of interactions between the environment and the animal are a result of combined action of both neurons and endocrine
system for which specialized tissues are used to provide control and co – ordinations activities. Nervous system that includes

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 brain, spinal cord along with other peripheral nervous transfer the information for procesisng. The endocrine system releases
hormones in response to stimulus to control and co-ordinate the functions.
20. a. i. Testis: to produce male gametes.
ii. Scrotum: to provide optimal temperature to testis for the formation of sperm.
iii. Vas deferens: to deliver the sperms to the urinary bladder.
iv. Prostrate glands: to secrete the fluid which provides nutrition and medium for transport of sperms.
b. Conventionally, the motile germ-cell is called the male gamete and the germ-cell containing the stored food is called the
female gamete.
21. i. All offsprings were round yellow in F1 - generation
ii. Round yellow - 9
Round green - 3
Wrinkled yellow - 3
Wrinkled green - 1
Therefore, the ratio of offsprings in F2-generation is 9 : 3 : 3 : 1.
Section D
22. i. The green plants capture about 1% of the energy of sunlight that falls on their leaves for the process of photosynthesis.
ii. The flow of energy in an ecosystem is always unidirectional. It is said to be unidirectional because some energy is lost in
form of heat when moving from one trophic level to the next for the maintenance of the homeostasis of an organism.
iii. If 10J of energy is available to the tertiary consumers, the secondary consumers will get 100J of energy.the primary consumers
will thus get 1000 J of energy.
OR
The 10 percent law of energy flow states that when the energy is passed on from one trophic level to another, only 10 percent
of the energy is passed on to the next trophic level.
Section E

23. a. Diagram of human excretory system

b. Functions:
Kidney → Filtration of blood
Ureter → Transports urine from kidney to bladder
Urinary Bladder → Stores Urine
Urethra → Throws out urine/Excrete Urin
24. a. i. Ovary
Production of Estrogen hormone
Production of female gamete/egg
ii. Oviduct
Transfer of female gamete from the ovary to uterus
Site of fertilisation
iii. Uterus
Implantation of zygote

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 Nourishment of the developing embryo
b. Placenta - It is a disc embedded in uterine wall which contains villi on the embryo side of the tissue and blood space on
mother side.
Function of placenta: Provides nourishment to embryo from mother’s blood / Removal of waste from embryo to mother’s
blood.

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