Observe the given diagram and answer the questions given below:
Identify the correct statements with respect to the female gametophyte.
A. Three cells at the chalazal end group together to form an egg apparatus.
B. Female gametophyte is also known as embryo sac.
C. Six of the eight nuclei in the embryo sac are surrounded by cell walls and organised into cells.
D. Megaspore mother cells form four megaspores by meiotic division
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → B, C and D only
A. Three cells at the chalazal end group together to form an egg apparatus. — Incorrect. The egg apparatus (two synergids and the egg cell) lies at the micropylar end. The three cells at the chalazal end are the antipodals.
B. Female gametophyte is also known as embryo sac. — Correct. The functional megaspore develops into the female gametophyte, the embryo sac.
C. Six of the eight nuclei in the embryo sac are surrounded by cell walls and organised into cells. — Correct. The other two, the polar nuclei, lie in the large central cell.
D. Megaspore mother cells form four megaspores by meiotic division — Correct. Meiosis of the megaspore mother cell gives a tetrad of four megaspores.
NCERT Extract:
The Pistil, Megasporangium (ovule) and Embryo Sac – “… Six of the eight nuclei are surrounded by cell walls and organised into cells; the remaining two nuclei, called polar nuclei are situated below the egg apparatus in the large central cell. There is a characteristic distribution of the cells within the embryo sac. Three cells are grouped together at the micropylar end and constitute the egg apparatus.”
The Pistil, Megasporangium (ovule) and Embryo Sac – “… Meiosis results in the production of four megaspores (Figure 1.8a).”