AP Biology, Chapter 46
Animal Reproduction

SUMMARY
INTRODUCTION

OVERVIEW OF ANIMAL REPRODUCTION
	Both asexual and sexual reproduction occur in the animal kingdom
		1. Distinguish between asexual and sexual reproduction.
			a. Asexual
				i. One parent
				ii. Genetically identical offspring
				iii. Quicker
				iv. Good in constant environments
			b. Sexual
				i. Two parents
				ii. Genetically recombinant offspring
				iv. Good in changing environments
		2. List and describe four forms of asexual reproduction.
			a. Fission is splitting
			b. Budding involves a branch
			c. Fragmentation involves breakage with regeneration
			d. Pathenogenesis is development of unfertilized eggs
	Diverse mechanisms of asexual reproduction enable animals to produce identical 
	offspring rapidly
	Reproductive cycles and patterns vary extensively among animals
		3. Describe an example of an animal life cycle that alternates between asexual and 
		sexual reproduction.
			a. Daphnia. Aphids, rotifers
			b. Favorable conditions  parthenogenesis
			c. Unfavorable  sexual
		4. Explain how hermaphroditism is advantageous in sessile or burrowing animals that 
		might have difficulty encountering a member of the opposite sex.
			a. Hermaphroditism = each individual produces sperm and eggs
			b. May self-fertilize
			c. Or, every individual is a potential mate

MECHANISMS OF SEXUAL REPRODUCTION
	Introduction
	Internal and external fertilization both depend on mechanisms ensuring that mature 
	sperm encounter fertile eggs of the same species
		5. Describe three mechanisms that increase the probability that mature sperm will 
		encounter fertile eggs of the same species in organisms that use external fertilization.
			a. Specific mating behaviors
			b. Environmental cues like day length
			c. Pheromones
	Species with internal fertilization usually produce fewer zygotes but provide more 
	parental protection than species with external fertilization
		6. Compare reproductive systems using internal and external fertilization on the basis of 
		the relative number of zygotes, protection of the embryos, and parental care.
			a. External
				i. Many zygotes
				ii. Unprotected embryos
				iii. Few give parental care
			b. Internal
				i. Few zygotes
				ii. Embryos are protected
				iii. Better parental care
	Complex reproductive systems have evolved in many animal phyla

MAMMALIAN REPRODUCTION
	Human reproduction involves intricate anatomy and complex behavior
		7. Differentiate the sperm-producing and hormone-producing structures of the testes. 
			a. Sperm-producing: seminiferous tubules
			b. Hormone-producing: interstitial cells
		8. Differentiate the contributions of the seminal vesicles, prostate gland and 
		bulbourethral glands to semen.
a. Seminal vesicles make sugar, vitamin C, prostaglandins
b. Prostate makes alkaline fluid
c. Bulbourethral glands make a cleansing, lubricating mucus
	Spermatogenesis and oogenesis both involve meiosis but differ in three significant 
	ways
		9. Differentiate meiosis and mitosis.
			a. Number of divisions: mitosis one, meiosis two
			b. Number of chromosomes: mitosis maintains, meiosis reduces by half
		10. Contrast spermatogenesis and oogenesis.
			a. Cytokinesis: equal in males, unequal in females
			b. Production over a lifetime: continuous in males, suspended at birth in females
			c. Continuity: no arrest in sperm production, two in egg production
	A complex interplay of hormones regulates reproduction
		11. Compare and contrast the functions of LH and FSH in male and female reproductive 
		function. 
			a. Luteinizing hormone
				a. Female: triggers ovulation and the development of the corpus luteum
				b. Male: stimulates interstitial cells in the testes to produce testosterone
			b. Follicle-stimulating hormone
				a. Female: stimulates the maturation of ova and follicles
				b. Males: stimulates production of sperm
	Embryonic and fetal development occur during pregnancy in humans and other 
	eutherian (placental) mammals
		12. Describe the events of human development beginning with a sperm and egg and 
ending with implantation.
	a. Mitotic cleavage to 100 cells
	b. Hollows out to form blastocyst with inner cell mass
	c. Implants by day 7 after ovulation
		13. List the major functions of the placenta.
			a. Delivers nutrients and oxygen
			b. Removes wastes
			c. Replaces corpus luteum by producing estrogen and progesterone
	Modern technology offers solutions for some reproductive problems