Many frogs and mice are similar in size, yet a frog egg is vastly larger than a mouse egg. Propose a plausible explanation for this difference in the egg size.

During human gestation, rudiments of all organs developa. in the first trimester.b. in the second trimester.c. in the third trimester.d. during the blastocyst stage.

Summarize the experimental evidence that Daphnia require three cues to trigger sexual reproduction. Discuss what these cues indicate about the environment.

Which of the following is mismatched?a. urethra: sperm passage;b. testes: hormone production;c. vas deferens: semen production;d. seminiferous tubules: sperm production

Which of the following is a true statement?a. All mammals have menstrual cycles.b. The endometrial lining is shed in menstrual cycles but reabsorbed in estrous cycles.c. Estrous cycles are more frequent than menstrual cycles.d. Ovulation occurs before the endometrium thickens in estrous cycles.

The production of gametes .a. begins at puberty in males and females;b. requires that the testes of males produce semen;c. results in the production of diploid cells from haploid cells;d. begins at puberty in females;e. produces sperm and eggs that carry half the number of chromosomes as nongametes

For which of the following is the number the same in human males and females?a. interruptions in meiotic divisionsb. functional gametes produced by meiosisc. meiotic divisions required to produce each gameted. different cell types produced by meiosis

How do spermatogenesis and oogenesis in humans differ with respect to numbers of cells produced, gamete size, and timing of the second meiotic division?

Which statement about human reproduction is true?(A)Fertilization occurs in the vagina.(B)Spermatogenesis and oogenesis both require normal body temperature.(C)An oocyte completes meiosis after a sperm penetrates it.(D)The earliest stages of spermatogenesis occur closest to the lumen of the seminiferous tubules.