12Science Biology

Smt.P.A.Sodha Sar. Marathi Highschool & A.M.Vhora Jr.College,Navapur Dist. Nandurbar
Class- 12 th Science.
Unit Test Exam.
Subject: Biology                             Marks-25

Section A

Q- 1
Multiple Choice Questions :           (7)
1. The three cells found in a pollen grain when it is shed at 3-celled stage are a) 1 vegetative cell, 1 generative cell, 1 male gamete
b) 1 vegetative cell, 2 male gametes
c) 1 generative cell, 2 male gametes
d) either (a) or (b).
2. The female gametophyte of a typical dicot at the time of fertilisation is a) 8 – celled b) 7 – celled c) 6 – celled d) 5 – celled
3. Growth of pollen tube towards embryo sac is
a) chemotropic b) thigmotaxis c) geotropic d) none of these
4. During the process of fertilization the pollen tube of the pollen grain usually enters embryo sac through
a) micropyle b) nucellus c) chalaza d) integument
5. Fusion of one of the male gametes with egg nucleus is referred to as
a) generative fertilization 

b) syngamy       

 c) vegetative fertilization 

 d) both (a) and (b)
Answer in one sentence.
1. What is Genotype?
2. What is cryptorchidism ?
              Section B
Attempt any Four of the following .(8-Marks)
Q.3 Explain the functions of calyx and corolla .
Q.4 What are the reasons for Mendel’s success ?
Q.5 Write a note on IVF.
Q.6 Explain chromosomal theory of inheritance.
Q.7 Why law of dominance is not universal ?
Q.8 What is colostrum ?

                 Section C
Attempt any Two of the following(6)
Q.9 Describe the phases of menstrual cycle .
Q.10 What is cris-cross inheritance ?
Q.11 What is Hydrophily ? Give any one example .
                  Section D
Attempt any One of the following (4Marks)
Q.12 Describe the process of double fertilization.
Q.13 Describe female reproductive system of human. Sent from my iPhone