11.4: Sexual reproduction

key vocabulary

prior learning & retrieval practice

Essential idea: Sexual reproduction involves the development and fusion of haploid gametes.

U1: Spermatogenesis and oogenesis both involve mitosis, cell growth, two divisions of meiosis and differentiation.

U2: Processes in spermatogenesis and oogenesis result in different numbers of gametes with different amounts of cytoplasm.

Exercise 1: watch the videos below and connect extend challenge

Exercise 2: Outline the role of mitosis and meiosis in gametogenesis. You may wish to review these processes (1.6, 3.3, 10.1)

Exercise 3: Compare and contrast spermatogenesis and oogenesis

S1: Annotation of diagrams of seminiferous tubule and ovary to show the stages of gametogenesis.

Exercise 4: Complete "learn" for the following quizlet decks

S2: Annotation of diagrams of mature sperm and egg to indicate functions.

Exercise 5: Complete "learn" for the following quizlet decks

U3: Fertilization in animals can be internal or external.

U4: Fertilization involves mechanisms that prevent polyspermy.

Guidance:

• Fertilization involves the acrosome reaction, fusion of the plasma membrane of the egg and sperm and the cortical reaction.

Exercise 6: Give an example of an animal species that uses external fertilization and one the uses internal fertilization?

Exercise 7: Outline the mechanism the prevent polyspermy in animals

A1: The average 38-week pregnancy in humans can be positioned on a graph showing the correlation between animal size and the development of the young at birth for other mammals.

Exercise 8: Describe the relationship between animal size and the development of young at birth. What does this indicate about humans.

U5: Implantation of the blastocyst in the endometrium is essential for the continuation of pregnancy.

U6: HCG stimulates the ovary to secrete progesterone during early pregnancy.

U7: The placenta facilitates the exchange of materials between the mother and fetus.

U8: Estrogen and progesterone are secreted by the placenta once it has formed.

U9: Birth is mediated by positive feedback involving estrogen and oxytocin.

Exercise 9: Explain the process of embryonic development following implantation and the role of the planceta.

NoS: Assessing risks and benefits associated with scientific research—the risks to human male fertility were not adequately assessed before steroids related to progesterone and estrogen were released into the environment as a result of the use of the female contraceptive pill. (4.8)

Exercise 10: What risks are there to human make fertility from societal use of the contraceptive pill?