What is true about cleavage in the fertilized egg in humans?
Correct answer: A. It starts while the egg is in the fallopian tube
- A. It starts while the egg is in the fallopian tube
- B. It starts when the egg reaches the uterus
- C. It is meroblastic
- D. It is identical to the normal mitosis
Explanation
Cleavage is a series of rapid mitotic divisions of the zygote which convert the single-celled zygote into a multicellular structure called blastula (blastocyst). About thirty hours after fertilization, the newly formed zygote divides into two cells, the blastomeres, in the upper portion of the Fallopian tube. This is the first cleavage. The next division occurs within forty hours after fertilization. The third division occurs about three days after fertilization. During these early cleavages, the young embryo is slowly moving down the Fallopian tube towards the uterus. At the end of the fourth day, the embryo reaches the uterus. It has thirty-two cells.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Reproduction
Human reproduction covers the male and female reproductive organs, gamete formation, fertilization, implantation and hormonal regulation. The menstrual cycle includes ovarian and uterine changes controlled by pituitary and ovarian hormones, while sexually transmitted diseases are studied through their causes, transmission, symptoms, prevention and effects on fertility.
Practise Reproduction
1,220 free Reproduction MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.