25.16 Reproductive technology has benefits and dangers.

Many methods exist that help otherwise infertile couples have children.

Question 25.26

When do cells begin to lose their totipotency?

  • a) anaphase of mitosis
  • b) gastrulation
  • c) late prophase I of meiosis
  • d) cleavage
  • e) neurulation

Question 25.27

The phenotype of an individual who is genetically XY but is lacking the sex-determining region on the Y chromosome will be:

  • a) a person who does not have testes but does have male external sex organs.
  • b) completely male, because of low estrogen levels.
  • c) either male or female, depending on whether the person carries the gene for dHT, which directs development of the penis.
  • d) a person with ovaries and female secondary sex characteristics.
  • e) completely male, because the person will produce testosterone, which masculinizes the internal and external reproductive organs.

Question 25.28

In humans, fetal growth is slowest during which trimester?

  • a) first
  • b) second
  • c) third
  • d) fourth
  • e) It occurs at the same rate in all trimesters.

Question 25.29

In which of the following methods ofassisted reproductive technology does fertilization occur within the woman’s body ?

  • a) intracytoplasmic sperm injection
  • b) in vitro fertilization–embryo transfer (IVF-ET)
  • c) zygote intra-Fallopian transfer (ZIFT)
  • d) gamete intra-Fallopian transfer (GIFT)
  • e) All of the above are correct.