Free Human Reproduction (Daily Quiz: 7) NEET Biology Questions & Answers with Detailed Explanation & Full Review

Answer: (b)

In vitro fertilization is a process where fertilization of egg occurs outside the mother’s womb. This method is used as a major treatment for infertility. This method involves the removal of eggs from the female ovaries. This egg is then allowed to fertilize with sperm in a fluid medium in a test tube. The zygote is allowed to develop for a week. Either zygote or early embryo up to 8 blastomeres is then transferred into the fallopian tube to complete its further development. If the embryo is with more than 8blastomeres, it is transferred into uterus for successful pregnancy. A baby conceived by fertilization that occurs outside mother body is called test-tube baby.

Answer: (b)

Each human testis is oval in shape, with a length of about 4-5 cm and a width of about 2-3 cm.

Answer: (d)

Implantation in endometrial uterine wall takes place at blastocyst stage of embryonic development. Before implantation, the blastomeres of early blastocyst get arranged into an outer layer called trophoblast and an inner group of cells attached to trophoblast called inner cell mass. It is the trophoblast layer through which blastocyst gets attached to the endometrium and the inner cell mass gets differentiated as the embryo.

Answer: (d)

In humans, the secondary oocyte is produced when the primary oocyte grows in size and completes its first meiotic division. The secondary oocyte will be halted at this stage of metaphase of meiosis II until fertilisation takes place. Thus, when a sperm cell fertilises the female sex cell, the secondary oocyte rapidly completes the remaining stages of meiosis II, giving rise to ovum, with which the sperm cell unites.