KENDRIYA VIDYALAYA SANGATHAN JAMMU REGION

HALF YEARLY EXAMINATION 2024-25

Class XI Max. Marks: 70
Subject: Biology Time Allowed: 3 Hrs

General instruction: (i) All questions are compulsory.

(ii) The question paper has five sections and 33 questions.
(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 labelled diagrams should be drawn.

Q. Question Marks
No. (SECTION A)

1 The correct descending order of taxonomic categories are: 1

A. Species -> Genus -> Order -> Class
B. Species -> Genus -> Family -> Order
C. Kingdom -> Phylum -> Class -> Order
D. Class -> Genus -> phylum -> species

2 Harmful toxins released during Red tide may cause death of aquatic animals. 1
These red tides caused by:
A. Euglena B. Slime moulds
C. Gonyaulax D. Amoeba
3 Identify the correct botanical name of mango among the following: 1
A. Homo sapiens B. Mangifera indica
C. Solanum nigrum D. P. leo

4 The smallest living cell that can survive without oxygen is: 1
A. Mycoplasma B. Chlamydomonas
C. Nostoc D. Anabaena

5 Among the following plants , the gametophyte is the dominant phase in: 1
 A. Amphibians of plant kingdom B. Pteridophyte
C. Angiosperms D. More than one option is correct.

6 Development of zygote into young embryo takes place inside female 1

gametophyte, this leads to
A. Seed habit B. Heterospory
C. Homospory D. Both a and c are correct

7 Water canal system is present in : 1

A. Sponges. B. Porifera.
C. Sycon D. All of the above

8 Which among the following is a poikilothermes animal: 1

A. Whales B. Humans
C. Lizards D. Sparrow

9 Frogs have the ability to mimic it's surrounding by changing their color 1
according to its surroundings to hide from the enemy. This ability of frog is
called:
A. Hibernation B. Aestivation
C. Camouflage D. Both a and b

10 There is a specific pattern of leaf arrangement in stem varies from species to 1

species.
(A) Alternate- Alstonia. (B) Opposite- Calotropis
Select among the following:
A. Both are correct match B. Both are incorrect match
C. Only A is correct D. Only B is correct

11 Identify the incorrect statement about the dicot root anatomy: 1

A. Root hairs arise from the epidermis.
B. Tissue outside endodermis constitute stele.
C. Casparian strip is water impermeable due to suberin.
D. Radial vascular bundles are present in roots.
12 Among the following, in which type of chromosome the centromere are slightly 1
above the centre
A. Acro-centric B. Meta-centric
 C. Telo-centric D. Sub-meta centric

Question 13-16 are assertion and reason questions.

A. If both the assertion and reason are correct and the reason is the correct
explanation of the assertion.
B. If both the assertion and reason are correct and the reason is not the
correct explanation of the assertion.
C. If assertion is correct and the reason is incorrect.
D. If both the assertion and reason are incorrect.

13 Assertion: In passive diffusion there is movement of particle from lower 1

concentration to its higher concentration.
Reason: Na+/K+ pump doesn't require ATP for its functioning.

14 Assertion: The enzyme easily converts the substrate into product. 1

Reason: The activation energy reduces in the presence of enzyme.

15 Assertion: Meiosis II is known as equational division. 1

Reason: The number of chromosomes reduced from 2n to n.

16 Assertion: There is a special type of leaf anatomy present in C4 plants known as 1

Kranz anatomy.
Reason: In these leaves the Bundle sheath cells are present around vascular
bundle surrounded by Mesophyll cells
(SECTION B)

17 Why wheat is called C3 and sorghum a C4 plant. Name the first compound 2
produced in C3 and C4 plants.
Or
Explain the law of limiting factor by using CO2 as an example. 1+1

18 In which phase of cell cycle does these following events takes place (any two): 2
(a) Crossing over (b) Synaptonemal complex.
(c) Chiasmata (d) DNA replication.
19 How is banana different from mango fruit? 2

20 A mutual association between organisms is provides benefit to both. Explain 2

one such association among the lower organisms which does not come under
 the 5 kingdom system of classification.
Or
Eukaryotes are more close to Archaebacteria than Eubacteria.
What are the different categories of Archaebacteria?

21 Write the two differences between Non-chordates and Chordates. 2

(SECTION C)

22 The distribution of Bryophytes and Pteridophytes is limited near damp and 2+1
moist area due to their certain requirements. Explain those. Give example of
each group.

23 The respiratory organ in plants is different from that of animals. What are the 3
tiny structures present on the plants for gaseous exchange? Draw a well
labelled diagram of it.

24 Differentiate between prokaryotic and eukaryotic cell. 3

25 Match the following: 3

A. B.
1. Gill slits a. Mammalia
2. Hairs b. Ctenophora
3. Comb plates c. Porifera
4. Scales d. Pisces
5. Tympanum e. Reptilia
6. Oviparous f. Aves
g. Amphibians

26 Draw a well labelled diagram of internal organs of frog showing complete 3

digestive system.
Or
A frog has different types of sense organs. Explain.

27 Write one or two words for the following: (any 6) 0.5×6=

(a) The most abundant protein in animal world. 3
 (b) The most abundant protein in plant world.
(c) The exoskeleton of arthropods.
(d) Nucleic acid contain all the genetic information in organisms.
(e) Monomeric unit of polypeptide chain.
(f) Alkaloids, flavonoids , rubber, essential oils released by plants.
(g) Haemoglobin 4 chains.

28 One cannot write the scientific name in any language or any way, there are 3
specific set of rules. Explain 3 rules of writing a scientific name with example.
(SECTION D)

29 Observe the diagram below and answer the following questions: 1+1+1+
1

(a) Name the process shown in the diagram.

(b) What does LHC stands for?
(c) What is/are the products of this process?
(d) Where does it takes place?
Or
(d) Is it light or dark reaction.

30 The activity of enzyme can be affected by change in various conditions. Study 1+2+1
the following graphical representation and answer the following questions.
(a) Name the factor that can affect enzyme activity.
(b) What would happen if the temperature of the medium increases and
decreases by 10°C than the optimum temperature.
(c) Define competitive inhibition.
Or.
(c) Define lock and key hypothesis.
 (SECTION E)

31 Differentiate between the 5 Kingdoms stated by R. H. Whittaker on the basis of 5

their cell type, mode of nutrition, body organization, nuclear membrane and
cell wall.
Or
1+1+1+
Observe the given diagram carefully and answer the following questions: 1+1

(a) Label A, B, C, D parts shown in the diagram.

(b) What is the genetic material present in it.
(c) The genetic material is protected by _______.
(d) Identify the organism.
(e) Write one symptom of the disease caused by TMV.

32 Do gamete formation takes place in a haploid organism. If yes, name the type 0.5+0.5
of cell division occur to form gametes. Write significance of Mitosis and Meiosis +2+2
each.
Or
a) Distinguish cytokinesis and karyokinesis.
b) Describe the events takes place during interphase. 2+2+1
c) What is G0 of cell cycle?

33 What is aestivation in flowers? Explain different types of aestivations by using 5

suitable illustration.
Or
What is placentation in angiosperms? Explain different types of placentation by
using suitable illustration.