Question

From the statements given below, choose the options that are true for a typical female gametophyte of a flowering plant. (i) It is 8-nucleate and 7-celled at maturity.
(ii) It is free-nuclear during the development.
(iii) It is situated inside the integument but outside the nucellus.
(iv) It has an egg apparatus situated at the chalazal end.

• A. (i) and (iv)
• B. (ii) and (iii)
• C. (i) and (ii)
• D. (ii) and (iv)

Hint:

Typical angiosperm embryo sac is \(8\)-nucleate and \(7\)-celled. Egg apparatus is always at the micropylar end.

Answer 1

The Correct Option is C

Concept:
The female gametophyte of a flowering plant is also called the embryo sac. A typical mature embryo sac in angiosperms is: \[ \text{8-nucleate and 7-celled} \] It develops through free-nuclear divisions, meaning nuclear divisions occur first without immediate wall formation.

Step 1: Check statement (i).
A typical mature female gametophyte has: \[ 3 \text{ antipodal cells} + 2 \text{ synergids} + 1 \text{ egg cell} + 1 \text{ central cell} \] The central cell contains two polar nuclei. So, total nuclei: \[ 3+2+1+2=8 \] Total cells: \[ 3+2+1+1=7 \] Thus, statement (i) is correct.

Step 2: Check statement (ii).
During embryo sac development, the functional megaspore undergoes mitotic divisions without immediate cell wall formation. This is called free-nuclear development. So, statement (ii) is also correct.

Step 3: Check statement (iii).
The embryo sac is situated inside the nucellus. It is not situated outside the nucellus. Therefore, statement (iii) is incorrect.

Step 4: Check statement (iv).
The egg apparatus is situated at the micropylar end, not at the chalazal end. The chalazal end contains antipodal cells. So, statement (iv) is incorrect.

Step 5: Final conclusion.
The correct statements are: \[ (i)\ \text{and}\ (ii) \] Hence: \[ \boxed{\text{(C) (i) and (ii)}} \]