Animal Reproduction and Development Study Guide

Learning Objectives

1. Compare and contrast gamete formation in males and females.

2. Compare and contrast reproductive anatomy in males and females.

Key Concepts to Understand (Chapter 47)

• Asexual Reproduction: Reproduction involving a single parent that results in offspring genetically identical to the parent.

• Sexual Reproduction: Involves the fusion of gametes (sperm and egg) from two parents, leading to genetic diversity.

• Gametogenesis: The process by which gametes are produced; spermatogenesis in males and oogenesis in females.

Reproductive Structures and Fertilization

• Male Reproductive Structures: Testes, penis, and associated glands serve to produce and deliver sperm.

• Female Reproductive Structures: Ovaries, fallopian tubes, uterus, and vagina assist in egg production and nurturing the embryo.

• Fertilization: The union of sperm and egg, typically occurring in the fallopian tubes.

Egg Development and Embryonic Stages

• Stages of Embryonic Development:

  • Cleavage: Rapid cell division leading to the formation of a blastula.

  • Gastrulation: Rearrangement of the cells to form three germ layers - ectoderm, mesoderm, and endoderm.

  • Organogenesis: Development of organs and tissues.

Sex Hormones in Mammalian Reproduction

• Key Hormones:

  • Testosterone: Important for male reproductive development and function.

  • Estradiol and Progesterone: Key hormones in female reproduction, regulating menstrual cycle and pregnancy.

• Hypothalamic and Pituitary Regulation:

  • Gonadotropin-releasing hormone (GnRH) stimulates the release of LH and FSH.

Menstrual Cycle

• Stages:

  • Follicular Phase: Preparation of ovarian follicles.

  • Ovulation: Release of an egg from the ovary.

  • Luteal Phase: Preparation for potential implantation of an embryo.

• Hormonal Regulation: Estrogen and progesterone maintain the cycle and support the endometrial lining.

Pregnancy and Birth

• Key Terms:

  • Gestation: Period of development from fertilization to birth.

  • Implantation: The embedding of the embryo into the uterine wall.

  • Human chorionic gonadotropin (hCG): Hormone produced to maintain the corpus luteum early in pregnancy.

• Role of Oxytocin: Influences uterine contractions during labor.

Other Important Concepts

• Cleavage Outcomes: Increases cell number without growth; forms the blastula.

• Gastrulation Outcomes: Establishes three primary germ layers critical for organ formation.

• Organogenesis: Involves spatial organization and cell signaling impacting cell fate and differentiation.

Exam Preparation

• Review diagrams of reproductive structures and hormonal pathways.

• Understand the roles and timing of hormone action during the menstrual cycle.

• Be able to describe contraceptive methods and their mechanisms.

• Prepare for explanations on the stages of embryonic development and their significance in animal reproduction.