Question

The arrangement of (i) cells and (ii) nuclei in a typical embryo sac is -

• A. (i)(3 + 1 + 3) & (ii)(3 + 2 + 3)
• B. (i)(3 + 2 + 3) & (ii)(3 + 1 + 3)
• C. (i)(3 + 1 + 3) & (ii)(3 + 1 + 3)
• D. (i)(3 + 2 + 3) & (ii)(3 + 2 + 3)

Answer 1

The correct option is A

(i)(3 + 1 + 3) & (ii)(3 + 2 + 3)

A typical embryo sac has 7 cells and 8 nuclei. There are 3 antipodal cells at the chalazal end, one central cell and 3 cells in the egg apparatus (one egg and two synergids). Hence, the cellular arrangement is 3+1+3. The antipodals and the three cells of the egg apparatus have one nucleus each. The central cell however has two free nuclei known as the polar nuclei. Therefore, the arrangement of nuclei is 3+2+3.