HBSE Class 11 Sample Paper 2025 Answers Biology

Board Of School Education Haryana

मॉडल पेपर
उत्तर
2025

MARKING SCHEME (2024-25)
CLASS – XI
BIOLOGY
Q. No Expected Answer/ Value Point Marks

1. b, Triticum aestivum 1
2. b, Archae bacteria 1
3. b, Volvox 1
4. Androecium/stamens 1
5. b, Synovial joint 1
6. Annelida 1
7. C, Mitochondria 1
8. Endoplasmic reticulum 1
9. Nitrogen 1
10. b, Manganese / Mn 1
11. a, Carbohydrate 1
12. a, Gibberellins 1
13. Pyruvic acid 1
14. Adrenaline and nor adrenaline (ony one) 1
15. b Urea 1
16. b, A & R both are true but R is not correct explanation of A. 1
17. C, A is true, but R is false. As the narrowing of blood vessles
is also due to deposition of calcium and fibrous tissue besides
fat and cholesterol. 1
18. B, A & R both are true but R is not correct explanation of A. 1

Section-B
Intra cellular digestion Extra cellular digestion
19. 1. Digestion with in cell 1.Digestion is in between cells. 1
2. e.g. Amoeba Few
enzymes are involved. 2. e.g. man Number of enzymes 1
involved.(Any two)
Or
Direct Development Indirect development
1. Young ones resemble the 1. Young ones do not resemble 1
adults in all respect. the adults.
2. No intermediate stage. 2. Larval stage is intermediate 1
stage

20. Angiosperms and Gymnosperms are seed procducing
plants but they are classified differently because
1. Angiosperms are flowering plants and Gymnosperms 1
are non flowering.
2. In angiosperms seeds are enclosed in fruits but in 1
gymnosperms seeds are naked as there is no fruit formation.

Q. No Expected Answer/ Value Point Marks

Or
Heterospory is a phenomenon in which two kinds of spores are
borne on the same plant. The two kinds of spores differ in size 2
& produce male & female gametophyte.
Formation & retention of zygote takes place on female
gametophyte.
Heterospory is thus considered an important step in
evolution as it is a precursor to the seed habit.
21. Pinnately Compound leaf Palmate compound leaf
1. Midrib is elongated. Midrib is disc shaped 1
2. Leaf lets are present along Leaf lets are attached to a 1
the midrib. common point.
22. Mesosomes. Invagination/ interdigitation of plasma 1
membrane in bacterial cell.
Functions :
1. Involved in cytokinesis. 1/2
2. Bears enzymes esential for oxidising food. 1/2
Or
Metacentric : Centromere is exactly in the centre and the 1/2
two arms are equal.
Submetacentric : Centromere is slightly away from centre and 1/2
the two arms are unequal.
Telocentric : Centromere is towards the terminal area. 1/2
Acrocentric : Centromere is is subterminal. 1/2
23. A leaf kept dark for long becomes yellow or pale green because 1
of disintegration of chlorophyll Carotenoid which provide yellow 1
colour are more stable.
24. Hypothalamic Harmones - Pituitary. 1/2
Thyrotrophin (TSH) - Thyroid. 1/2
Corticotropin - Adrenal cortex. 1/2
Gonadotropin (LH, FSH) - Ovary/Testis 1/2
25. (a) Smooth muscles iv) Involuntary 1/2

(b) Tropomyosin ⅱ)
Thin filament 1/2

(c) Red muscle I) myoglobin ½

(
d)Skull iii)Sutures 1/2

Q. No Expected Answer/ Value Point Marks

26. C3 Pathway C4 Pathway

1.RUBP is Primary acceptor. PEP is Primary acceptor. 1
2.Optimum temperature for Optimum temperature is 1
photosynthesis is 10-
25°
C. 30-
45°
C

3.Phosphoglyceric acid is Oxaloacetic acid is first 1
first product. product.
Or
Cyclic Photophosphorylation Non Cyclic
Photophosphorylation

1.Performed by photo Performed by both 1
system-
I independently. photosystem I &
II

2.It synthesises ATP only. It synthesises ATP and 1
NADH2

3.It is not connected with It is connected with 1
photolysis of water. photolysis of water

27. Kreb'
s cycle

CO +PEP C4 acid Mesophyll cell. 1
2
C4 acid C3 Acid Bundle Sheath cells 1
Calvin cycle

Regeneration
C3 acid PEP Mesophyll cells 1

28

OR
3

Q. No Expected Answer/ Value Point Marks

29. Hypogynous-Gynoecicm occupies highest position, 1
while other parts are situated below it
Perigynous-Gynoecicm in centre 1
Other parts are located on the rim of the thalamus almost
at the same level.
- is enclosed inside the thalamus other
Epigynous Ovary 1
parts are inserted above the ovary
30 (a)Operculum iv)Osteichthyes. 1/2
(b)Parapodia vii)Annelida 1/2
(c)Radula ii)Mollusca 1/2
(d)Choanocytes I)Porifera 1/2
(e)Gill slits iii)cyclostomes. 1/2
(f)Comb plates v)Ctenophora 1/2
31. 1. ?) Lack membrane band nucleus. 1/2
?) Lack: Cell organelles 1/2
2. Lysosomes 1
3. In mitochondria ATP is produced that is why it is 2
called powerhouse of cell.
Or
Smooth ER:Synthesis of lipids.
Golgi apparatus:It is packing organelle.

32. (
a)A -
Troponin 1/2
B -
Tropomyosin 1/2
(
b)A Masks
- the active site of actin filament.
(
c)Monomer of C:Meromyosin, C is Actin 2
Or
Myosin bears actin binding sites, through which it binds to
actin filament.
33. Protozoans belong Kingdom Protista. 1
Chrysophytes -
Diatoms and Desmids. 1
Dinoflagellates -
Gonyaulax 1
Fuglendids -
Euglena 1
Sporozoans -
Plasmodium 1

Q. No Expected Answer/ Value Point Marks

33. Or
Economic importance Algae :-
1. Half of the CO?fixation is carried out by algae Porphyra,
Laminaria and Sargassum are used as food. 1
2. Water holding are Substances like algin carrageen are
obtained from algae. 1
3. Chlorella is used as food supplement. 1
Economic importance of gymnosperms.
1. In cycas small specialised roots called coralloid roots are
associated with N2 fixing cyanobacteria. 1
2. In Pinus the roots are associated with fungus
in the form of mycorrhiza. 1
34. Substages of Phase I-
of Meiosis-I
1.Leptotene:Chromosomes show compaction and it
continues throughout the stage. 1
2.Zygotene:Homologous chromosomes start pairing
together and this process of association is called synapsis.
The paired chromosomes are called bivalents. 1
3.Pachytene:The bivalent is seen as tetrad Crossing over
occurs between non-sister chromatids. 1
4.Diplotene:It is characterised by the dissolution of
syraptonemal complex and formation of Chiastmata takes place. 1
5.Diakinesis:It is marked by terminalisation of chiastmata. 1
Or
Mitosis Meiosis
1.occurs in somatic cells/ Occur in germinal cells. 1
General body cells.
2.It is equational division. It is Reductional division. 1
3.From one parent cell,bour two From one Parent cell our
daughter cells are produced. daughter cells are produced. 1
4.No Crossing over. Crossing over lakes place. 1
5.It is short process. It is long process. 1

Q. No Expected Answer/ Value Point Marks

35. Fishes have a 2 chambered heart with an
atrium and a ventricle. 1
Amphibian an reptiles except
( crocodile)have a 3 chambered
heart with two atria and a single ventricle. 2
Crocodile,birds and mammals possess a 4 chambered heart
with two atria and two ventricles. 2
Or
Cardiac cycle:- All the four chambers are in relaxed
state i.
e.diastole. 1
* The bicuspid and tricuspid values are open and blood
flow into left and right ventricles. ½
* Semi lunar values are closed
* SAM now generates an action potential which
stimulates simultaneous contraction of atria. 1/2
• This increases the blood flow in ventricles, due to which
the action potential is conducted in ventricles through
AVN & AV bundle, and bundle of HIS, as a result the
ventricles contract and atria relax. 1/2
* Ventricular systole causes closure of bicuspid &
tricuspid values semi lunar values open. 1/2
* Ventricles diastole causing closure of semilunar values. 1/2
* As the pressure declines the tricuspid & bicuspid values
are pushed open & the joint diastole is achieved. 1/2
Cardiac output: In one cardiac cycle 70 mL of blood is
pumped and heart pumps 72 minutes so total volume of
blood pumped 70 x 72= approximately 5000ml or 5 litres. 1

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