GARDEN HIGH SCHOOL

CLASS X

Half-Yearly Examination, 2023–24

Biology

Time: 2 hours Full Marks: 80

This Question Paper has nine printed pages.

Answers must be written in the script/s provided. You will not be allowed to write for the
first 15 minutes. This time must be spent in reading the Question Paper.
The time given at the head of this Paper is the time allowed for writing answers.

This Paper is divided into two sections.

Answer all the parts of Q No 1 and Q No 2 (Section A) and any four questions of Section B.
Maximum marks for a question or part of a question are given in brackets [ ].

SECTION A (40 marks)

Answer all the questions.

Question No 1
Choose the correct answers to the questions from the given options. (Do not copy the
question, write the correct option only.) [15]

(a) In a dihybrid cross, which of the following will be regarded as heterozygous?

(i) RRTT (ii) Rr (iii) rrtt (iv) RrTt

(b) Which of the following is not an excretory activity?

(i) Formation and removal of carbon dioxide through lungs
(ii) Formation and removal of uric acid through sweat
(iii) Formation and removal of faecal matter
(iv) Formation and removal of urea through urine

(c) A boy pressed his finger on his radial artery. After every few seconds, he felt a
throbbing sensation. His biology teacher explained that he was feeling his pulse which
is produced due to ______ and he was indirectly counting his ______.
(i) ventricular systole, heart sound
(ii) auricular systole, heartbeat
(iii) ventricular systole, heartbeat
(iv) auricular systole, heart sound
 (2)

(d) How many pairs of autosomes are present in human beings?

(i) 44 (ii) 23 (iii) 22 (iv) 46

(e) Assertion (A): Blood flows through glomerulus under intense pressure.
Reason (R): The afferent arteriole is narrower than the efferent arteriole.
(i) Both A and R are true and R is the correct explanation of A.
(ii) Both A and R are true but R is not the correct explanation of A.
(iii) A is true and R is false.
(iv) A is false and R is true

(f) Lata self-pollinated some red flowered plants. Out of the 80 offsprings, 20 were white
flowering plants and the rest red flowering plants. Thus, the type of plants Lata did her
experiments on were
(i) homozygous dominant . (iii) homozygous recessive.
(ii) heterozygous. (iv) pure breed.

(g) Which statement is not true about lymph?

(i) Lymph contains water, leukocytes, organic and inorganic substances.
(ii) Lymph contains water, blood platelets, organic and inorganic substances.
(iii) Lymph drains back into the major anterior veins near the right auricle.
(iv) Lymph absorbs digested fat through lacteals and across intestinal villi.

(h) In the iodine test, a blue-black colour indicates

(i) the absence of glucose. (iii) the presence of starch.
(ii) the presence of glucose. (iv) the absence of starch.

(i) In a dicot leaf palisade parenchyma is present between

(i) the upper and the lower epidermis.
(ii) the upper epidermis and the spongy parenchyma.
(iii) the lower epidermis and the spongy parenchyma.
(iv) the cuticle and the upper epidermis.

(j) Photophosphorylation is
(i) the process of conversion of ATP into ADP during photosynthesis in the presence
of sunlight.
(ii) the process of conversion of ADP into ATP during photosynthesis in the presence
of sunlight.
(iii) the process of conversion of ADP into ATP during photosynthesis in the absence of
sunlight.
(iv) the process of conversion of ATP into ADP during photosynthesis in the absence of
sunlight.
 (3)

(k) The hormones which promote cell elongation and thereby the growth of plants are
(i) auxin and ADH. (iii) gibberellins and ADH.
(ii) auxin and gibberellins. (iv) auxin and ABA.

(l) Assertion (A): Balsam plants wilt during mid-day, even if the soil is well watered.
Reason (R): The rate of transpiration is less during mid-day than absorption of water.
(i) Both A and R are true, and R is the correct explanation of A.
(ii) Both A and R are true, but R is not the correct explanation of A.
(iii) A is true and R is false.
(iv) A is false and R is true.

(m) The population of cheetah in a wildlife sanctuary was declining. Scientists concluded
that the population was declining because
(i) mortality > natality. (iii) mortality = natality.
(ii) natality > mortality. (iv) natality – mortality > 0.

(n) DNA is absent in

(i) the nucleus. (iii) the mitochondria.
(ii) the chloroplasts. (iv) the centrosome.

(o) The metabolic reaction which releases oxygen during photosynthesis is

(i) photolysis of water. (iii) dark reaction.
(ii) ultrafiltration. (iv) polymerization.

Question No 2
(a) Name the following: [5]
(i) The ion, the concentration of which causes the opening and closing of stomata
(ii) The substance present in an excess in the urine, if a person is suffering from
diabetes mellitus
(iii) The ground substance present in chloroplast
(iv) A surgical method of fertility control in human males
(v) The stable compound which is formed when carbon monoxide reacts with
haemoglobin

(b) Arrange and rewrite the terms in each group in a logical sequence beginning with the
term that is underlined. [5]
(i) efferent arteriole, renal vein, afferent arteriole, glomerulus, secondary capillary
network
 (4)

(ii) place the plant in sunlight, destarch, make an outline on paper, iodine test, pluck a
leaf after a few hours.
(iii) interphase, anaphase, prophase, telophase, metaphase
(iv) cortex, root hair, stoma, intercellular space, xylem, sub-stomatal space
(v) cell sap, cytoplasm, call wall, cell membrane, tonoplast

(c) Fill in the blanks with suitable words: [5]

The injured tissue cells and the (i) disintegrate at the site of a wound and releases
a substance called (ii) . It acts as an enzyme and with the help of calcium ions
present in the plasma, it converts inactive (iii) into active (iv) . This active
substance in the presence of inorganic ions converts soluble (v) into insoluble
fibrin.

(d) Choose the odd one out from the following terms and name the category to which the
others belong: [5]

(i) adenine, thymine, guanine, thiamine, cytosine

(ii) cohesion, imbibition, capillary action, adhesion, active transport
(iii) NADPH, O2, ATP, electron, CO2
(iv) stroma, stomata, hydathodes, lenticels
(v) Coleus, Croton, Hydrilla, geranium

(e) Match the items given in Column I with the most appropriate ones in Column II and
rewrite the correct matching pairs. [5]

Column I Column II

(i) Rh+ (A) no antigen on RBC or antibody in the plasma

(ii) AB (B) antigen B on RBC and antibody a in the plasma

(iii) O (C) D antigen present on RBC

(iv) A (D) antigen A on RBC and antibody b in the plasma

(v) B (E) no antigen on RBC both antibodies in the plasma

(F) antigen A and antigen B on RBC but no antibody

in the plasma

(G) antigen B on RBC and antibody b in the plasma

(H) antigen A on RBC and antibody a in the plasma

 (5)

SECTION B (40 marks)

Answer any four questions.

Question No 3
(a) Ravi kept raw bananas inside a paper bag. After two days he opened the bag and saw
that they had ripened. Explain why. [1]
(b) Give the full forms of: [2]
(i) ORS (ii) IAA
(c) Give two structural differences between monocyte and eosinophil. [2]
(d) Give reason why the cortex of human kidney shows a dotted appearance whereas the
medulla shows a striped appearance. [2]
(e) Study the diagram and answer the following questions: [3]

(i) Name the process taking place in A and B.

(ii) State a characteristic feature of:
(A) 1 which is allowing the process in A to take place.
(B) 2 which is allowing the process in A to take place.

Question No 4
(a) X-linked recessive diseases are more common in males than in females. Why? [1]
(b) Name the pigments present in: [2]
(i) urine (ii) RBC
(c) In the experiment to prove that carbon dioxide is necessary for photosynthesis, state the
functions of: [2]
(i) potassium hydroxide (ii) methylated spirit

(d) In the population versus time graph given below, what do the two question marks
indicate? [2]
 (6)

(e) Artificial pollination is a method of crop improvement programme. Raju wanted to grow
an improved wheat crop variety that will give a better yield. He sprinkled four varieties
of pollen grains S1, S2, S3, S4 of non-specific origin on the stigma of wheat plants. The
following (A, B, C) were the results of his experiment. [3]

(i) Name the type of movement shown by the pollen grains S3 and S4.
(ii) What was the stimulus of the movement in (i)?
(iii) Pollen grain S1 had not germinated whereas S4 showed pollen tube formation.
Explain why.

Question No 5
(a) Differentiate between nucleotide and nucleosome. [1]

(b) The following experimental set-up shows the process of osmosis. [2]

Study the diagram and explain what will happen if the cellophane paper is replaced with:
(i) a rubber sheet (ii) a muslin cloth

(c) Given below are four terms. Write them in a logical sequence to depict impulse
generation and conduction through the heart. [2]
Purkinje fibres, AVN, bundle of His, SAN

(d) State two adaptations in Nerium to reduce transpiration. [2]

 (7)

(e) A Mendelian cross was performed between two pea plants, one having homozygous
inflated shape of pods and another having homozygous constricted shape of pods.
Progenies from both F1 and F2 generations were obtained. [3]

(i) How many distinct types of gametes were formed in the F1 and F2 generations?
What were they?

(ii) Draw a Punnett square to represent the F2 generation.

(iii) State the phenotypic ratio and genotypic ratio of the F2 generation.

Question No 6
(a) Name the scientists who first worked out the double helical model of DNA. [1]

(b) What type of movements will be shown by the shoot and root of plants respectively if the
stimuli is: [2]
(i) sunlight?
(ii) force of earth’s gravity?

(c) State the dominant traits of the following characters in a pea plant: [2]
(i) colour of flower.
(ii) colour of seed.

(d) The inverted red triangle is a symbol used widely in hospitals. Answer the questions
with reference to the symbol. [2]
(i) What does the symbol depict?
(ii) State any one of the objectives associated with the symbol.

(e) Show, with the help of labelled diagrams, the differences between an artery and a vein. [3]

Question No 7
(a) Name an inorganic and an organic nitrogenous waste excreted through urine. [1]

(b) A blood vessel A brings blood from stomach and intestine to the liver. Inside the liver it
breaks up into capillaries and reunites to form a vein B which goes back to the heart
through the blood vessel C. Another blood vessel D enters the liver carrying
oxygenated blood from the heart. Name A, B, C and D. [2]

(c) State two characteristics of root hair that allows water molecules to pass from its higher
concentration to lower concentration. [2]
(d) Draw the labelled diagram of a plant cell undergoing anaphase with 2n = 6. [2]
 (8)

(e) Study the diagram and answer the following questions:

(i) The left kidney is placed slightly higher than the right kidney in this diagram.
Explain why. [1]
(ii) Differentiate between A and B based on the composition of blood flowing through
them. [1]
(iii) A circular muscle is present at the base of C. Name the muscle. What happens
when the muscle relaxes? [1]

Question No 8
(a) Why is the interphase in a dividing cell known as a resting phase? [1]

(b) What will happen to a plant cell when: [2]

(i) it is placed in an isotonic solution?
(ii) the turgor pressure exceeds the wall pressure?

(c) Draw the diagram of an open stomatal apparatus and label the cells present around the
stoma. [2]

(d) Four leaves were taken. Vaseline was applied on both the surfaces of leaf A, only on the
lower surface of leaf B and only on the upper surface of leaf C. Vaseline was not applied
on either surfaces of leaf D. [2]

(i) Among the four leaves which one would shrivel faster and why?
(ii) Are the leaves taken from a monocot or a dicot plant? Give one reason for your answer.
 (9)

(e) A student drew the following diagram in the biology practical file. The teacher returned
the file stating that the diagram should be corrected by changing strand 2. [3]

(i) Redraw the correct diagram by changing strand 2.

(ii) Name the process of duplication of the above structure.