Class 11 Sample Paper 2024 Biology

Class XI SAMPLE QUESTION PAPER Maximum Marks: 70
Biology (044) Time: 90 Minutes

General Instructions:

(i) All questions are compulsory.
(ii) The question paper has five sections and 33 questions. All questions are compulsory.

(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section–
C has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and
Section–E has 3 questions of 5 marks each.
(iv) There is no overall choice. However, internal choices have been provided in some questions. A
student has to attempt only one of the alternatives in such questions.
(v) Wherever necessary, neat and properly labeled diagrams should be drawn.

Q. No. SECTION - A

1 Which of the following does not come under taxon?
(a) Species(b) Kingdom
(c) Division(d) Key

2 The asexual spores are not found, vegetative reproduction occurs by fragmentation and
sexual organs are absent. Identify the class of fungi.
(a) Phycomycetes (b) Ascomycetes
(c) Basidiomycetes (d) Deuteromycetes
3 Iodine is found in
(a) Spirogyra(b) Laminaria
(c) Polysiphonia(d) Chlorella
4 Phylum that doesn’t have a true coelom is
(a) Platyhelminthes(b) Annelida
(c) Echinoderms(d) Arthropoda

5

Label the parts of a monocot seed.
(a) A.Endosperm, B. Scutellum, C. Radicle, D. Coleoptile, E. Plumule
(b) A.Endosperm, B. Coleoptile, C. Scutellum, D. Radicle, E. Plumule
(c) A.Endosperm, B. Scutellum, C. Coleoptile, D. Radicle, E. Plumule
(d) A.Endosperm, B. Scutellum, C. Coleoptile, D. Plumule, E. Radicle
6 The term phyllotaxy is used to describe the
(a) type of ovary in a plant b) mode of arrangement of leaves
(c) type of roots(d) arrangement of sepals and petals
7 Closed vascular bundles lack
(a) pith(b) xylem

(c) cambiumd) xylem vessels
8 Tendons connect the following:
(a) bone to boneb) muscle to muscle
(c) cartilage to muscle(d) bone to muscle

9 Middle lamella is made up of ___________.
(a) calcium sulphideb) calcium pectate
(c) calcium carbonated) calcium chloride

10 With reference to enzymes, which one of the following statements is true?
(a) Apoenzyme = Holoenzyme + Coenzyme
(b) Holoenzyme = Apoenzyme + Coenzyme
(c) Coenzyme = Apoenzyme + Holoenzyme
(d) Holoenzyme = Coenzyme – Apoenzyme

11 Choose the correct sequence. A. Pachytene B. Zygotene C. Leptotene D. Diakinesis E.
Diplotene
(a) C, B, A, D, E
(b) C, A, B, E, D
(c) C, B, A, E, D
(d) D, B, C, E, A

12 Mobilization of stored food in germinating seeds is triggered by
(a) auxins (b) cytokinins
(c) gibberellins(d) ethylene
Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R).
Answer these questions by selecting the appropriate option given below:
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true and R is not the correct explanation of A.
C. A is true but R is false.
D. Both A and R are False.
13 Assertion: Haemoglobin is an oxygen carrier.
Reason: Oxygen binds to NH2 of haemoglobin.
14 Assertion: Thrombocytes play an important role in blood coagulation.
Reason: They are produced by the fragmentation of megakaryocytes.
15 Assertion: The epithelial cells of PCT have a brush border.
Reason: Luminal surfaces of the epithelial cells are provided with microvilli.
16 Assertion: Rheumatoid arthritis is a viral disease.
Reason: It is commonly known as ‘wear and tear’ arthritis
SECTION B
17 State universal rules of nomenclature.

18 Classify the chromosomes based on the positions of centromeres.

19 What is meant by tertiary structure of proteins?

20 How is arithmetic growth different from geometric growth?

21 How do you distinguish between a skeletal muscle and a cardiac muscle?
OR
Diffusion of gases occurs in the alveolar region only and not in other parts of the
respiratory system. Why?

SECTION – C

22 i) What are heterocysts?
ii) What is a viroid?
iii) What are aplanospores?

23 In which plant will you look for Mycorrhiza and coralloid roots? Also explain what these
terms mean.
24 Give three major differences between chordates and non-chordates.

25 Draw a neat labelled diagram of a dorsiventral leaf.

26 Frogs can respire on land and in water. Describe the different methods used by them for
respiration.
27 Enumerate the different classes of enzymes.
OR
Draw a neat, labelled structure of chloroplast.
28 Aquatic animals are generally ammonotelic in nature whereas terrestrial forms are not.
Comment.
SECTION - D

29

In fermentation, say by yeast, the incomplete
oxidation of glucose is achieved under anaerobic conditions by sets of reactions where
pyruvic acid is converted to CO2 and ethanol. The enzymes, pyruvic acid decarboxylase
and alcohol dehydrogenase catalyse these reactions. Other organisms like some bacteria
produce lactic acid from pyruvic acid. In animal cells also, like muscles during exercise,
when oxygen is inadequate for cellular respiration pyruvic acid is reduced to lactic acid by
lactate dehydrogenase. The reducing agent is NADH+H+ which is reoxidised to NAD+ in
both the processes. In both lactic acid and alcohol fermentation not much energy is
released; less than seven per cent of the energy in glucose is released and not all of it is
trapped as high energy bonds of ATP. Also, the processes are hazardous – either acid or
alcohol is produced. Yeasts poison themselves to death when the concentration of alcohol
reaches about 13 per cent.

In eukaryotes these steps take place within the mitochondria and this requires O2. Aerobic
respiration is the process that leads to a complete oxidation of organic substances in the
presence of oxygen, and releases CO2, water and a large amount of energy present in the
substrate. This type of respiration is most common in higher organisms.

1.) Under ______________________ condition incomplete oxidation of respiratory
substrate takes place.
a) Aerobic
b) Anaerobic

c) Aerobic and anaerobic

d) None of the above
2.) In fermentation process,
a) pyruvic acid is converted to O2 and ethanol
b) pyruvic acid is converted to CO2 and ethylene
c) pyruvic acid is converted to CO2 and ethanol
d) pyruvic acid is converted to CO2 and ethephon
3.) Name the enzyme which facilitates the reactions where pyruvic acid is converted to
CO2 and ethanol.
4.) Name the process which leads to a complete oxidation of organic substances in presence
of oxygen.

30 The thyroid gland is composed of two lobes which are located on either side of the trachea.
Both the lobes are interconnected with a thin flap of connective tissue called isthmus. The
thyroid gland is composed of follicles and stromal tissues. Each thyroid follicle is
composed of follicular cells, enclosing a cavity. These follicular cells synthesize two
hormones, tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3). Iodine is
essential for the normal rate of hormone synthesis in the thyroid. Deficiency of iodine in
our diet results in hypothyroidism and enlargement of the thyroid gland, commonly called
goitre. Hypothyroidism during pregnancy causes defective development and maturation of
the growing baby leading to stunted growth (cretinism), mental retardation, low intelligence
quotient, abnormal skin, deaf-mutism, etc. In adult women, hypothyroidism may cause the
menstrual cycle to become irregular. Due to cancer of the thyroid gland or due to
development of nodules of the thyroid glands, the rate of synthesis and secretion of the
thyroid hormones is increased to abnormally high levels leading to a condition called
hyperthyroidism which adversely affects the body physiology.
Exophthalmic goitre is a form of hyperthyroidism, characterised by enlargement of the
thyroid gland, protrusion of the eyeballs, increased basal metabolic rate, and weight loss,
also called Graves’ disease. Thyroid hormones play an important role in the regulation of
the basal metabolic rate. These hormones also support the process of red blood cell
formation. Thyroid hormones control the metabolism of carbohydrates, proteins and fats.
Maintenance of water and electrolyte balance is also influenced by thyroid hormones.
Thyroid gland also secretes a protein hormone called thyrocalcitonin (TCT) which regulates
the blood calcium levels.
i.) _______________ Protein hormone secreted by thyroid gland regulates the blood
calcium levels along with PTH.

a) thyromelatonin
b) thyrocalcitonin

c) thyrocalciumtonin

d) thyrocarbotonin

ii.) cretinism is referred as,
a) stunted growth due to deficiency of iodine
b) stunted growth due to deficiency of thyroid hormones
c) mental retardation due to deficiency of iodine
d) deaf-mutism due to deficiency of iodine
iii.) Explain how the both lobes of the thyroid gland are interconnected?
iv.) Give the composition of thyroid follicle and their function?
SECTION E

31 Write briefly, the significance of mitosis and meiosis in multicellular organisms.
OR
Describe Watson and Crick’s model of DNA structure.
32 List the salient features of the Calvin cycle. Why are the plants having this cycle called C3
plants?
OR
Give the schematic representation of the overall view of Krebs cycle. Where does it take
place?
33 Name the parts of the human forebrain indicating their respective functions.
OR
Explain the different types of blood groups and donor compatibility by making a table.

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