Reproduction — Set 4
Biology · प्रजनन · Questions 31–40 of 50
Which part of the sperm contains the mitochondria to provide energy for swimming?
Correct Answer: B. Midpiece
The midpiece of the sperm is packed with mitochondria that produce ATP. This energy powers the flagellum or tail, allowing the sperm to swim toward the egg. High motility is a crucial factor in male fertility.
The periodic shedding of the uterine lining in the absence of fertilization is?
Correct Answer: C. Menstruation
Menstruation occurs at the end of the menstrual cycle when estrogen and progesterone levels drop. The blood and tissue of the endometrium are discharged through the vagina. A typical menstrual cycle lasts about 28 days.
Which of the following describes the 'Endometrium'?
Correct Answer: A. Inner lining of the uterus
The endometrium thickens every month in preparation for a potential pregnancy. It is the site where the blastocyst implants to grow. If no implantation occurs, this lining is shed during menstruation.
Which chromosome determines the male sex in humans?
Correct Answer: A. Y chromosome
In humans, males have one X and one Y chromosome (XY). Since the mother always provides an X, the sex of the child is determined by whether the father's sperm carries an X or a Y. The Y chromosome contains the SRY gene which triggers male development.
The fluid that surrounds the developing fetus in the womb is?
Correct Answer: D. Amniotic fluid
Amniotic fluid allows the fetus to move freely, which is important for bone and muscle development. It also protects the fetus from physical impact and umbilical cord compression. Swallowing this fluid helps in the development of the fetal digestive system.
What is the process of producing mature female gametes called?
Correct Answer: A. Oogenesis
Oogenesis takes place in the ovaries and results in the formation of a haploid egg cell. Unlike sperm production, the process begins before birth and is completed only after fertilization. One primary oocyte typically results in only one functional egg.
Which hormone is primarily responsible for the thickening of the uterine lining?
Correct Answer: B. Estrogen
Estrogen is produced by the developing follicles in the ovary. It stimulates the growth of the endometrium after menstruation. It also regulates various other female secondary sexual characteristics.
The narrow lower part of the uterus that opens into the vagina is the?
Correct Answer: B. Cervix
The cervix produces mucus that changes in consistency to either facilitate or block sperm entry. During childbirth, the cervix must dilate significantly to allow the baby to pass. It is a common site for medical screening, such as Pap smears.
Which of the following is an example of an external male reproductive organ?
Correct Answer: D. Penis
The penis serves as both the organ for urinary excretion and for delivering sperm into the female tract. It contains erectile tissue that fills with blood. The scrotum is the other primary external male reproductive structure.
How many functional eggs are produced from one primary oocyte during oogenesis?
Correct Answer: C. One
Oogenesis results in one large functional egg and three small polar bodies that eventually degenerate. This ensures that the egg retains almost all the cytoplasm and nutrients for the early embryo. In contrast, spermatogenesis produces four functional sperm cells.