Question

Given below are events that lead to pregnancy and the development of the embryo.

(i) Fertilization of the egg
(ii) Maturation of egg
(iii) Release of egg
(iv) Embedding of the zygote in the thickened uterine wall.
Which of the following options gives the correct order of sequence in which they occur?

• A. i, ii, iii, iv
• B. ii, i, iii, iv
• C. i, iv, ii, iii
• D. ii, iii, i, iv

Answer 1

The correct option is D

ii, iii, i, iv

The correct option is C.
The explanation for the correct option:
Option C:

1. Morula, blastula, gastrula, and organogenesis are the four stages of embryonic development.
2. Egg development can be separated into two distinct phases and usually takes around 14 days.
3. Up to 1000 eggs start to develop and mature during the early stage.
4. Gonadal hormone stimulation is necessary to promote continued development in the second stage of development.
5. A stage of the menstrual cycle is ovulation.
6. A 28-day menstrual cycle happens around day 14.
7. Ovulation specifically refers to the release of the egg (ovum) from the ovary of a female.
8. Fertilization is a multi-step, intricate process that takes 24 hours to complete.
9. The beginning of pregnancy and the start of a female's 280-day journey begin when male sperm and female ovum combine to form a zygote.
10. The zygote divides several times before entering the uterus.
11. As soon as it enters the uterus, it develops into a blastocyst.
12. The blastocyst penetrates the uterine wall. Implantation is the term for this action.

Final answer: The correct sequence is ii, iii, i, iv.