Topic 6 and 11 Reproduction

6.6 Reproduction

Essential Idea: Hormones are used when signals need to be widely distributed.

U5 A gene on the Y chromosomes causes embryonic gonads to develop as testes and secretes testosterone.

U6 Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.

U7 Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty.

U8 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones.

A4 The use of IVF of drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of hormones to induce superovulation and establish a pregnancy.

A5 William Harvey’s investigation of sexual reproduction in deer.

S1 Annotate diagrams of the male and female reproductive system to show names of structures and their functions.

NOS1 Developments in scientific research follow improvements in apparatus- William Harvey was hampered in his observational research into reproduction by lack of equipment. The microscope was invented 17 years after his death.

11.4 Sexual Reproduction

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.

U3 Fertilization in animals can be internal or external.

U4 Fertilization involves mechanisms that prevent polyspermy.

U5 Implantation of the blastocysts 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.

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

S1 Annotation of a diagram of seminiferous tubule and ovary to show the stages of gametogenesis.

S2 Annotations of diagrams of mature sperm and egg to indicate functions.

NOS1 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 female contraceptive pill.

6.6 Reproduction

Please review p. 334-340 in the Oxford IB Text, p. 538-54/544-545 in the Campbell text and p. 280-283 in your Biozone.

  1. Annotate the male and female reproductive systems below

  1. Hormones control puberty of males and females. Describe the functions of the below hormones for males and females at puberty.

Testosterone in boys / Estrogen in girls
  1. Outline the menstrual cycle. Make sure to include descriptions about the 4 major hormones involved (LH, FSH, Estrogen, and progesterone) as well as the endometrial lining of the uterus.

Days 1-5:

Days 6-14:

Day 15 (approx.):

Days 16-28:

Day 29- If the egg is not fertilized, the cycle begins again

  1. As with other hormones, the hormones of the menstrual cycle are controlled by feedback loops. In this case, it is controlled by negative AND positive feedback mechanisms involving ovarian and pituitary hormones. Using the below diagram, explain the negative feedback loops of estrogen and progesterone during most of the cycle, and the positive feedback loop of estrogen on days 12-14.

11.4Sexual Reproduction

Please review p. 449-510 in the Oxford IB Text, p. 542-543/548-549/560in the Campbell text and p. 421-429 in your Biozone.

  1. What are the differences and similarities between spermatogenesis and oogenesis?

Oogenesis / Spermatogenesis
Similarities
Differences
  1. Annotate the diagrams of a seminiferous tubule and ovary to show the stages of gametogenesis.

  1. Fertilization in animals can be internal or external. Explain the differences, and include real life examples of each.
  1. How does the process of fertilization prevent more than one sperm entering the egg (polyspermy)?

Stages of fertilization / Description
Acrosome reaction
Penetration of egg membrane
Cortical reaction
  1. How does HCG control the early stages of pregnancy?
  1. Birth is mediated by positive feedback involving estrogen and oxytocin. How do these hormones mediate the process of birth?

Hormone / Function in birth
Progesterone
Estrogen
Oxytocin