HBSE Class 11 Sample Paper 2024 Answers Biology

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2024
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During action potential, membrane is more permeable to Na+ ions as compared to K+ 1 2
23 She will categorize by observing the vascular bundles situated in following conditions:
(i)Scattered in monocot stem
Arranged in ring in dicot stem 1
(ii) Multicellular epidermal hairs are observed over the epidermis in monocot stem
Multicellular epidermal hairs are not observed over the epidermis in monocot stem
OR
Parenchyma:-Living cells, Thinwalled with intercellular space. 1 2
Collenchyma:- Thick walled living no intercellular space. 1

24 Sexual reproduction in fungi takes place in adverse environmental conditions with the help of two mating
thallus . 0.5
The different steps are:
Plasmogamy: It is the fusion of protoplasm 0.5
Karyogamy: It refers to fusion of nucleus 0.5
Meiosis: 2
In zygote, it involves cell cycle leading to nuclear division 0.5
25 Protonemal cell of moss: n, 0.5
Leaf cell of moss: n, 0.5
Prothallus cell of fern: n, 0.5
Gemma cup cell of marcantia: n, 0.5
2

Section- C
26 Three main features of Arthropods are as follows:
(i)Exoskeleton made up of chitin1
(ii)Jointed legs 1
(iii)Compound eyes 1
Or any other relevant character 3
27 Inflorescence can be defined as arrangement of flowers on the flowering axis. It comprises complete flower
head of a plant, including stem, stalk, bract and flower. Inflorescence is group or cluster of flowers like
sunflower, marigold attached to a stem. 1 Racemose inflorescence:
a) unlimited growth of shoot apex,
b) acropetal arrangement of flowers
Cymose inflorescence: 3
a) limited growth of shoot apex,
b) basipetal arrangement of flowers
OR
1+1+1

On the basis of insertion of pistil and other floral organs flowers can be hypogynous, perigynous and
epigynous.

2

28

1+1+
1=3

Diagram of

Diagram, showing Effect of pH on Enzymatic Activity 1
Diagram, showing Effect of temperature on Enzymatic activity 1
Diagram, showing Effect of substrate concentration on Enzymatic Activity
1

29 Skeletal muscle is composed of bundles of elongated muscle fibres. These are cylindrical and muti nucleated. 1
Skeletal muscle fibre shows a prominent banding pattern. The banding pattern has cross-striations of 2
alternating light and dark bands. The light bands are divided by a dark transverse line which is also called a z-
line. Between two Z lines is found one functional sub unit which is known as sarcomere.

3

30 The hormones released by Pancreas, Thyroid and Ovary are as follows: 3
Pancreas: Insulin, Glucagon 1
Thyroid: T3, T4 1
Ovary: Estrogen, Progesterone 1
OR

Diagrammatic representation of steroid hormone’s mechanism of action.
3

31 Differences between Prokaryotic and Eukaryotic cells:
a) Cells that have membrane bound nuclei are called eukaryotic whereas cells that lack a membrane bound
1 nucleus are prokaryotic. 0.5

b) Eukaryotic cells have membrane bound organelles like endoplasmic reticulum (ER), the Golgi complex,
lysosomes, mitochondria, microbodies and vacuoles. The prokaryotic cells lack such membrane bound
organelles. 0.5

4

Cytoplasm 1
a)Bacteria is prokaryotic because it
2 has no membrane bound nucleus 4
Genetic material is scattered in cytoplasm
3 c) Prokaryotic cell donot have membrane bound organelles like endoplasmic reticulum (ER), the Golgi
complex, lysosomes, mitochondria, 2 microbodies and vacuoles

OR
The names four membrane bound organelles are as given below:
a) Nucleus, b) ER, c) Lysosomes, d) Vacuole

32 1 Oxidative Decarboxylation: Removal of carbon along with oxidation i.e formation of acetyl coenzyme A
from pyruvic acid 1
2 3 NADH2and 1FADH2 1
4
3 3 and 4 carbon atoms respectively
Or
Two reactions in the cycle can be named as:
a) Decarboxylation
b) Regeneration, 2
33 Meaning of light reaction: Light reaction is light dependent synthesis of ATP and NADPH. It involves
cyclic and acyclic photophosphorylation.1
Different Modes of Light reactions can be explained through following diagrams:

1 2

5

2

OR
Five differences between C3 and C4 Plants are as follows:

5

Characteristic C3 plants C4 plants

In dark reaction
In dark reaction
of
of
Photosynthesis
Photosynthesis
process C4
Meaning process C3
plants use the C4
plants use the C3
pathway or
pathway or
Hatch-Slack
Calvin cycle
Pathway

Name of
Cool-season Warm-season
favourable
plants plants
Season

3 carbon 4 carbon
compound compound
Product
(Phosphoglyceri (Oxaloacetic
c acid) acid)

Kranz anatomy Absent Present

Optimum
Extremely low. High.
temperature

1*5

34

Diagram of Cardiac Cycle 2
Details of Cardiac cycle:
Cardiac cycle consists of Joint diastole of atria and ventricles 1 5
Atrial systole, Ventricular systole with atrial diastole 1
Ventricular diastole Total time of cardiac cycle is 0.8 seconds 1
OR
Connective tissue is one which connects body systems. Blood is one example which has an extra-cellular
matrix called plasma, with red blood cells,1 white blood cells, and platelets floating in it. The details are as
follows:
Plasma: 90-92 water and protein 1
Formed Elements: The three classes of formed elements are the erythrocytes also known as red blood cells,
leukocytes also known as white blood cells, and the thrombocytes also known as platelets.
Erythrocytes: Without nucleus, average life span 120 days 1
Leukocytes: Granulocytes and Agranulocyte 1
Thrombocytes: A tiny, disc-shaped piece of cell that is found in the blood forming blood clots to stop flow.
1
35 Mitosis:
a) Occurs in somatic cells
b) daughter cells are identical
c) no crossing over
d) short process

6

e) from one parent cell two daughter cells are produced
Meiosis:
a) Occurs in germinal cells
b) variation in daughter cells
c) crossing over is there
d) long process, from one daughter cell
e) four daughter cells are produced 1*5
OR
The prophase I of meiosis has following stages with respective details:
5
Leptotene: This is the beginning phase of prophase-I. It is characterised by the condensation of the chromosomes.
Zygotene: Homologous chromosomes start pairing up, known as the synapsis. The synaptonemal complex starts building
up. Bivalent chromosomes appear.
Pachytene: Non-sister chromatids of one homologous pair of chromosomes exchange their chromosomal parts. This
process is known as crossing over. Chiasmata is the attachment point of the crossing-over.
Diplotene: The crossing-over completes.
Diakinesis: The homologous chromosomes separate. Synaptonemal complex disappears. The nuclear membrane
disappears. 1*5

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