MIDTERM EXAMINATION(2019-20)

SUBJECT :BIOLOGY(044)

CLASS:XI

TIME:3HRS M.M:70

GENERAL INSTRUCTIONS:

There are a total of 27 questions and 4 sections in the question paper.All questions are

compulsory.

Section A contains question number 1 to 5,Very short answer type questions of 1 mark

each.

Section B contains question number 6 to 12, Short answer type I questions of 2 marks

each.

Section C contains question number 13 to 24, Short answer type II questions of 3

marks each.

Section D contains question number 25 to 27, Long answer type questions of 5 marks

each.

There is no overall choice in the question paper, however, an internal choice is

provided in 2 questions of 1 mark, 2 questions of two marks, 4 questions of three

marks and all 3 questions of five marks .In these questions, an examinee is to attempt

any one of the two given alternatives.

Wherever necessary, the diagram drawn should be neat and properly labelled.

SECTION-A

Q1. Give two examples of an algae used by an space travelers as

food supplements?(NCERT-Pg.32)

1

Ans. Chlorella, Spirullina ½ + ½

Q2. Write any one point of difference between tendons and

ligaments.(NCERT-Pg.103)

1

Ans. Tendons- attach skeletal muscles to bone

Ligaments-attach bone to another bone

½ + ½

Q3. Name two cell-organelles that are double membrane

bound.NCERT-Pg.141 Q7)

1

OR

Ans. Mitochondria and Chloroplast ½+ ½

What is mesosome in a prokaryotic cell. Mention any one

function that it performs.(Pg.141,Q5)

Ans. Special membranous structures formed by the extensions of

plasma membrane into the prokaryotic cells

½

Cell wall formation, DNA replication (any one) ½

Q4. Why is mitosis called equational division and meiosis as

reductional division?(NCERT-Pg,164,167)

1

Ans. Mitosis-same number of chromosome as that of parent cell ½

Meiosis- chromosome number gets halved ½

Q5. What is Bivalent?(NCERT-Pg, 172 Q7) 1

Ans. A pair of associated homologous chromosomes formed during

prophase I of Meiosis.

1

or

What is Go(quiescent phase) of cell cycle?( NCERT-

Pg171,Q4)

Ans. Nondividing phase outside of the cell cycle.

SECTION-B

Q6. Write a note on economic importance of algae and

gymnosperms.(any two points for each) (NCERT-Pg-44 Q6)

2

Ans. Algae-half of the total Co2 fixation on earth is carried out by an

algae, primary producers of energy rich compounds,

Laminaria, Sargassum edible algae.(Any two)

1

Gymnosperms-Ornamentals, Pine, Cedar source of soft wood,

Used in treatment of asthama, Seeds of pinus are edible.(Any

two)

1

Q7. a. How important is the presence of air bladder in

Pisces?(NCERT Pg-62.Q10)

1+1

b. Write any two modifications that are observed in birds that

help them fly?(NCERT Pg-62.Q11)

Ans. a. Regulate Buoyancy 1

b. Long bones are hollow with air cavities(Pneumatic bones),

Forelimbs are modified into wings, Streamlined body (Any

two)

½ + ½

Q8. Define the term inflorescence.Differentiate between Racemose

and Cymose inflorescence.(any 2 points of difference)(NCERT

Pg-83.Q13,Q6a)

2

Ans. The arrangement of flowers on the floral axis. 1

Racemose- main axis continues to grow, flowers borne

laterally in an acropetal order

½

Cymose-main axis terminates in a flower, flowers borne in a

basipetal order.

½

Q9. Describe the various types of placentations found in flowering

plants.(with eg.) (NCERT Pg-83.Q10)

2

Ans. Marginal(Pea),

Axile( china rose, tomato, lemon),

Parietal( Mustard, Argemone),

Free central ( Dianthus, Primrose),

Basal (Sunflower,Marigold). (Only one eg from

each)(Consider diagrams, explanation also)

2

Or

a. Which part of the plant is modified into

i) Pitcher in pitcher plant(NCERT 69)

ii) Tendrils in Pumpkin(NCERT Pg-68)

b. What do you understand by staminode and epipetalous

condition in flowers. (NCERT Pg-75)

Ans. a.i.

ii.

Leaves

Axillary bud(stem)

½ + ½

b. Sterile stamen, stamens are attached to petals ½ + ½

Q10. State the location and function of different types of meristems.

(NCERT Pg-99.Q1)

2

Ans. 1. Apical meristem-present at the apices of root and shoot,

increase in length

½ x 4

2. Intercalary-present at the bases of leaves above the nodes or

below the nodes, elongation of the organs.

3. Lateral-Present on the lateral side , increase in girth or

diameter.

Q11. What are the following and where do you find them in animal

body. (NCERT Pg-122.Q7)

2

a. Chondriocytes

b. Axons

Ans. a. Cells of cartilage, present in small cavities within the matrix

secreted by them.

½ + ½

b. Long, slender projections of neurons, help in carrying nerve

impulses from the neuron body.

½ + ½

Q12. A. Supply the specific scientific term for the following: 2

i) Extensive infolding of the inner membrane of mitochondria.

(NCERT Pg-135.)

ii) Stacks of closely packed thyllakoids . (NCERT Pg-136.)

B. Why the fluid nature of plasma membrane is important?

(NCERT Pg-132)

Ans. A.i. Cristae ½

ii. Grana ½

B. Cell growth, formation of intercellular junction, secretion,

endocytosis, cell division etc.(any two)

½ + ½

Or

Explain with the help of a diagram ultrastructure of

mitochondria. (NCERT Pg-135.)

Ans. NCERT Pg-135,fig.8.7

Double membrane bound, two aqueous compartments, inner

called matrix, cristae, specific enzyme associated , single

circular DNA.

1½+½

SECTION-C

Q13. Define triple fusion? What is the product of this process? Draw

the life cycle of an angiosperms. (NCERT Pg.41)

3

Ans. Fusion of one male gamete and diploid secondary nucleus.

Primary Endosperm Nucleus(PEN)

Pg-41,fig:3.6

½+

½+ 2

Q14. What is heterospory? Briefly comment on its significance.

Give two examples. (NCERT Pg-44.Q7)

3

Ans. Two kinds of spores are borne by the same plant.

Spores differ in size

Smaller- microspores

Bigger- megaspores

1

1

Crucial step in evolution as it is precursor to the seed habit.

Eg- Selaginella, Salvinia

1

Or

Explain briefly the following terms with suitable examples;

(NCERT Pg-45.Q8.)

i) Protonema

ii) Antheridium

iii) Archegonium

iv) Diplontic

v) Sporophyll

vi) Isogamy

Ans. a. Green, filamentous,branched structure developing from

haploid spores of moss after germination

½

` b. Male sex organ of Bryophytes, Pteridophytes ½

c. Female sex organ of Bryophytes, Gymnosperms ½

d. Life cycle of seed bearing plants(Gymnosperms, Angiosperms) ½

e. Leaf bearing sporangia ½

f. Fusion of similar size of gametes ½

Q15. Write the functions of the following structures: 3

i) Comb Plates (NCERT Pg-51.)

ii) Radula(NCERT Pg-53)

iii) Ostia(NCERT Pg-49)

iv) Parapodia(NCERT Pg-52)

v) Cnidoblast(NCERT Pg-50)

vi) Flame cells(NCERT Pg-51)

Or

A. Name the excretory organs of the following; 3

i) Arthropoda(NCERT Pg-53)

ii) Platyhelminthes(NCERT Pg-51)

iii) Hemichordata(NCERT Pg-54)

B. Distinguish between direct and indirect development with eg.

(NCERT Pg-62.Q5.)

Ans Locomotion

Rasping organ for feeding

½x6

Water enters through it

Swimming

Anchorage, defence and for the capture of prey

Osmoregulation and excretion

OR

i)

ii)

iii)

Malpighian tubule

Flame cells

Proboscis gland

½

½

½

B Development without any larval stage eg. Osteichthyes

Development with larval stage eg. Porifera etc

½

½

Q16. Write the floral formula of the following families(any two

families)

3

i) Fabaceae(NCERT Pg-79)

ii) Liliaceae(NCERT Pg-81)

iii) Solanaceae(NCERT Pg-80)

Ans i) % K(5)C1+2+(2)A(9)+1G1 1

1/2

ii) Br ⊕ P(3+3)A3+3G(3) 1

1/2

iii) ⊕ K(5)C(5)A5 G(2)S

Q17. Describe the arrangement of floral members in relation to their

insertion on thalamus. (NCERT Pg-83.Q15)

3

Ans. Hypogynous-gynoecium occupies highest position, other parts

below it, ovary superior .eg-mustard

Perigynous-gynoecium in the centre, other parts at the rim of

thalamus, ovary half inferior.eg- plum, rose etc

Epigynous-inferior ovary,margins of thalamus grows upward

enclosing the ovary completely eg.guava,cucumberetc

1

1

1

Q18. Describe briefly with the help of diagrams various types of

vascular bundles? (NCERT Pg-90.)

3

Ans. Radial-xylem,phloem arranged in an alternate manner on

different radii

Conjoint -xylem and phloem are situated at the same radius of

vascular bundles

a.closed-cambium absent

b.cambium present

1

1+1

Q19. Draw a labeled diagram of alimentary canal of cockroach..

(NCERT Pg-122.Q4)

3

Ans. Refer pg. 113, fig-7.16 NCERT(1/2 marks for drawing and 2 ½

marks for 5 labellings)

Q20. Explain briefly the types and fuctions of junctions found in the

epithelial and other tissues? (NCERT Pg-102)

3

Ans. a. Tight junction-help to stop substances from leaking across a

tissue

1

b. Adhering junction-perform cementing to keep neighbouring

cells together

1

c. Gap junctions-facilitate the cells to communicate with each

other

1

Q21. What is centromere ? How does the position of centromere

form the basis of classification of chromosomes. Support your

answer with a diagram showing the position of centromere on

different types of chromosomes. (NCERT Pg-141.Q14)

3

Ans. Primary constriction of chromosome

1

Refer Pg-139, fig.8.12 NCERT 2

Q22. a. What are nuclear pores? State their function. (NCERT Pg-

141.Q11)

3

b. Why lysosomes are called as suicide bags? (NCERT Pg-134)

Ans. a. Tiny holes present in the nuclear membrane of the nucleus

Function-holes allow specific substances to be transferred into

the cell cytoplasm and back into the nucleus.eg. RNA,

Protein(move in both directions, between the nucleus and the

cytoplasm)

1+1

b. Rich in hydrolytic enzymes(lipases,proteases,carbohydrases) 1

Q23. a. Illustrate a glycosidic and peptide bond. (NCERT Pg-160.Q2) 1+1

b. Name the most abundant protein present in animal world.

(NCERT Pg-148.)

c. Name the most abundant protein present in the whole of the

biosphere. (NCERT Pg-148.)

Ans. a.

b.

c.

Glycosidic –bonds linking the individual sugar units

Peptide bond–bonds link aminoacids in a protein

Collagen

RuBisCO

1+1

OR

What is meant by primary, secondary and tertiary structure of

proteins. (NCERT Pg-150,160.Q3)

Ans. Primary-linear structure of proteins, first amino acid called N-

terminal and last as C-terminal.

Secondary- linear protein folded in a form of helix

Tertiary-long protein chain folded upon itself like a hollow

woven ball , provides 3D view of a protein, necessary for

biological activities of proteins

½

1

1 ½

Q24. A. Name the stage of cell cycle at which one of the following

events occur: (NCERT Pg-172.Q6)

3

i) Chromosomes are moved to spindle equator.

ii) Centromere splits and chromatids separate.

iii) Pairing between homologous chromosomes takes place.

iv) Crossing over between homologous chromosomes takes place.

B. What is the average cell cycle span for a mammalian cell?

(NCERT Pg171.Q1)

C. Can there be mitosis without DNA replication in ‘S’ phase?

(NCERT Pg-172.Q14)

Ans. A. Metaphase

Anaphase

Zygotene of prophase I of meiosis

Pachytene of prophase I of meiosis

½x4

B. 24 hours ½

C. No ½

SECTION-D

Q25. a. Write any 3 points of difference between chordates and

nonchordates? (NCERT Pg-55)

1 ½

b. What is coelom? What are coelomate, Pseudocoelomate and

acoelomate animals.(With egs.) (NCERT Pg-48)

3 ½

Ans. a. Chordates-Notochord is present Nonchordates- notochord

Absent

CNS is dorsal,hollow and single Ventral,solid,double

Pharynx perforated by gill slits Gill slits absent

(Any other also)

1 ½

b. Body cavity which is lined by mesoderm

Coelomate-having coelom.eg.annelids,molluscs etc

Pseudocoelomate-mesoderm present in scattered

pouches.eg.aschelminthes

Acoelomates-body cavity absent.eg.platyhelminthes

(Or any other egs)

½

1

1

1

Or

a. Why Coelenterates are called Cnidarians? (NCERT Pg-50)

b. Enumerate the differences between Polyp and Medusa.

(NCERT Pg-50)

c. To which phylum liver fluke and tapeworm belong? Write

their scientific name. (NCERT Pg-51)

Ans. Cnidoblast or cnidocytes(stinging capsules or nematocytes)

present on the tentacles and the body.

1

Polyp-sessile,cylindrical form eg. Hydra, Adamsia

Polyp produces medusae asexually

Medusae-Umbrella-shaped,free-swimming like Aurelia or

jelly fish

Medusae form the polyp sexually

1+1

c. Platyhelminthes

Taenia, Fasciola

1+1

Q26. Explain the process of secondary growth in the stems of woody

angiosperms with the help of schematic diagrams. What is its

significance? (NCERT Pg-99.Q3)

5

Ans. Refer Pg. 95,fig.6.9

Significance- increase in girth , produces corky bark around

the tree trunk that protects the interior from heat, cold and

infection.(or any other)

4+1

Or

Draw illustrations to bring out the anatomical difference

between(NCERT Pg-99.Q4)

i) Monocot root and Dicot root 2 ½

ii) Monocot stem and Dicot stem 2 ½

Ans. i.

ii.

Refer Pg.91,fig.6.6

Refer Pg.92,fig.6.7

2 ½

2 ½

Q27. a. Write the significance of Mitosis and Meiosis. (NCERT Pg-

167,172.Q12)

5

b. Describe the events taking place during interphase. (NCERT

Pg-171.Q3)

Ans. a. Mitosis-Production of identical genetic component in daughter

cells, Cell growth, Cell repair

Meiosis-Conservation of specific chromosome number of each

species is achieved, increases the genetic variability in the

population of organisms ,variations are very important for the

process of evoluions.

b. G1 phase-involes RNA and Protein synthesis, Metabolically

active

S phase-DNA replication

G2 phase- RNA and Protein synthesis

Refer Pg.163,fig.10.1

Or

a. Draw a labeled sketches to the different phases of mitosis in

animal cell. (NCERT Pg-165,167)

3

b Who gave cell theory? Write its important points. 2

Ans. a.

2 ½

b. Schleiden and Schwann

i.all living organisms are composed of cells and products of

cells.

ii.all cells arise from pre-existing cells.

2 ½