Question

Which of the following situations correctly describes the similarity between an angiosperm egg and a human egg?
(i) Eggs of both are formed only once in a lifetime.
(ii) Both the angiosperm egg and human egg are stationary.
(iii) Both the angiosperm egg and human egg are motile transported.
(iv) Syngamy in both results in the formation of a zygote.

Choose the correct answer from the options given below.
A. (ii) and (iv)
B. (iv) only
C. (iii) and (iv)
D. (i) and (iv)

Answer 1

Hint: In the Human reproductive system, the egg cell or the ovum, is the female gamete or reproductive cell. Fertilization occurs when the female gamete meets the sperm in the fallopian tube, leading to the formation of a zygote.

Complete answer:
In Angiosperms, the ovary contains ovules, these seeds develop into female gametophytes which further develop into the egg. The sperm nuclei fuse with these eggs by the process of double fertilization and lead to the formation of a zygote.

Let us analyze the statements one by one to find the correct answer-
 i) Eggs of both are formed only once in a lifetime- In the Human reproductive system, from the period of Menarche to Menopause, one egg is ovulated per month and thus they are formed more than once in a lifetime.
In Angiosperms, as well, eggs are produced in every reproductive cycle therefore contradicting the above statement. Thus this statement is incorrect.

ii) Both the angiosperm egg and human egg are stationary- In the Human reproductive system, the eggs or oocytes are released from the ovary, which then moves to the fallopian tube by the beating of cilia, to the uterus. Fertilization occurs in the fallopian tube. Thus, human eggs are motile and not stationary.
In Angiosperms, the eggs are formed in the ovary and they stay there until they are fertilized by the male nuclei. These eggs are stationary.
So, the above statement holds true for angiosperms eggs but not for human eggs.

(iii) Both the angiosperm egg and human egg are motile transported- As explained above, the human eggs are motile and are transported from the ovary to the uterus but the angiosperm eggs are non-motile and stay in the ovary. Therefore, this statement holds true for human eggs but not for angiosperms eggs.

(iv) Syngamy in both results in the formation of a zygote- Syngamy is the term used for the process of fertilization, which is the fusion of two gametes, cells, or their polar nuclei to form a zygote.

In the Human reproductive system, the human egg and the sperm fuse in the ampulla part of the fallopian tube to form the diploid zygote.
In Angiosperms, double fertilization occurs, where one sperm cell fuses with the endosperm to form the triploid central cell whereas the other sperm cell fuses with the egg cell to form the diploid zygote. Therefore, the above statement holds true for both cases.
Since only the iv) statement holds true for both cases, it is the only correct option.

Hence, the correct answer is option (B)

Note: In angiosperms, the female gametophyte gets reduced to 8 cells in the ovule. From these 8 cells, the closest to the micropyle end( that’s where the pollen tube carrying the sperm cell enters from) is developed into an egg cell.
In the Human reproductive system, millions of primary oocytes are created during the embryonic stage which gets reduced to 1-2 million by the time of birth. After menarche, by the process of oogenesis, these cells enter the menstrual cycle where one egg is released per cycle.