Question

If the chromosome number in the root cell of Zea mays is 20, then what would be the chromosome number in the cell of (i) radicle, (ii) hypocotyls, (iii) epiblast, (iv) aleurone layer and (v) scutellum, respectively?

	(i)	(ii)	(iii)	(iv)	(v)
$\left(1\right)$	20	30	20	30	20
$\left(2\right)$	20	20	20	30	20
$\left(3\right)$	20	30	30	30	20
$\left(4\right)$	20	20	20	20	20

• A. $\left(1\right)$
• B. $\left(2\right)$
• C. $\left(3\right)$
• D. $\left(4\right)$

Answer 1

Answer: (B)

Maize, Zea mays, is a monocotyledonous plant under the group of Angiosperm. It displays double fertilization, where a 2n zygote forms in first fertilization and a 3n primary endosperm nucleus forms in second fertilization which results in formation of aleurone layer.
Given maize plant has 20 chromosomes in root cell which is diploid. $2n=20;n=10$ .
Radicle, hypocityle, scutellum, epiblast are derivatives of embryo and will have $2n=20$ chromosomes each.
Aleurone layer is 3n, thus, it will have 30 chromosomes.