Bachelor of Science (B.Sc.) - Life Science
Term-End Examination

Time: 2 hours
Maximum Marks: 50

Note: Use separate answer sheets for Part I and Part II. Be brief and precise in your answers. Draw neat and labelled diagrams wherever necessary.

PART I

(Plants)

SECTION A

Note:(i) Question 1 is compulsory.

(ii) Draw labelled diagrams wherever necessary.

A1. Fill in the blanks. (1 x 5 = 5)

(a) ____ are present at the chalazal end of the embryo sac.

(b) Polyembryony is Commonly present in ____.

(c) A tropism in which the stimulus is by touch is called ____.

(d) ____ phloem is present in Salvadora

(e) Pollination brought up by insects is referred to as ____.

SECTION B

Note: (i) Attempt any four questions.

(ii) All questions carry equal marks.

B1. Distinguish between :

(i) Parthenogenesis and Parthenocarpy

(ii) Phototropism and Geotropism

B2. Write a short note on apical dominance.

B3. List some important applications of plant tissue culture.

B4. Explain the structure and functions of suspensor.

B5. Comment on the role of endosperm haustoria.

SECTION C

Note:

(i) Attempt any two questions.

(ii) All questions carry equal marks.

C1. Draw labelled diagrams of the following

(i) Mature anther

(ii) T.S. dicot stem (showing secondary growth)

C2. Write short notes on any two : (5)

(i) Phytochrome

(ii) Senescence

(iii) Pollen wall

C3. (a) Explain the following :

(i) Development of periderm

(ii) Distribution and structure of lenticels

(b) Describe briefly structure and functions of cambium. (2 + 3)

C4. Explain the biological significance of incompatibility. Describe the methods to overcome incompatibility. (2 + 3)

PART II

(Animals)

SECTION A

Note: Attempt all questions. Fill in the blanks in questions A1, A2 and A3.

A1. The ____ forms a cap over the sperm nucleus. (1)

A2. The ____ the carrier of genetic information present in every cell of all somatic tissues has similar composition. (1)

A3. The bones of forelimbs and hindlimbs of all vertebrates are serially ____.1

A4. Give one difference between any two pairs of the following terms (1 x 2)

(a) Oogenesis and Spermatogenesis

(b) Epiboly and Emboly

(c) Karyokinesis arid Cylokinesis

SECTION B

Note: Answer any two questions. Limit each answer to 200 words.

B1. (a) Explain the term metamorphosis

(b) Describe the process of complete metamorphosis in a moth. (2 + 3)

B2. (a) With the help of a diagram, describe life structure of a Graaflan follicle of a mammal.

(b) Classify the types of eggs on the basis of quantity of yolk present in them. (3 + 2)

B3. Write short notes on any two of the following:

(a) Neurulation in frog's embryo

(b) Formation of primitive streak in the chick embryo

(c) Prothoracic gland

SECTION C

Note: Answer any two questions. Each answer should not exceed more than 500 words.

C1. Explain the term malignancy. Describe the different stages in the development of cancer. (1 + 4)

C2. Describe Spemann's experiment to demonstrate Primary Embryonic Induction in early gastrula of an amphibian. (5)

C3. With the help of suitable diagrams, give an account of the stages of differentiation of lens in the eye of a vertebrate. (5)