Chapter 46 Animal Reproduction

1. Chapter 46Animal Reproduction Mark Lowder Carter Percy

2. Two Types • Asexual Reproduction (Greek for “without sex”) • One parent • Micro-organisms, hydras and protists • Some poeciliids or guppies (reproduction video) • Sexual Reproduction • Two parents • Joining of sperm and egg to create new life • Humans and mammals • Just about everything that can be seen by the naked eye • And hydras?

3. Asexual reproduction • Fission- the parent splits in two halves • Budding-new organism pops out of the old • Fragmentation and regeneration-organism breaks apart and parts grow into new, whole organisms

4. Starfish (haha Mr. Kuhn)

5. Sexual Reproduction Oddities • Parthenogenesis-eggs develop fertilized or unfertilized (common social insects) • Hermaphrodism-all members of the species develop both male and female parts • Sequential Hermaphrodism- sex changes later in life (ex. Caribbean blue headed wrasse)

6. Figure 46.4 Sex reversal in a sequential hermaphrodite. A male Caribbean blue headed wrasse and two smaller females feed on a sea urchin. All wrasses of this species are born female, but the oldest, largest fish complete their lives as males.

7. So how does it work?

8. Fertilization • What? • Joining of a female egg and a male sperm • Where? • External-outside in the environment • Internal-inside one of the parents

9. Something your book wants you to know about • Pheromones-chemical signals that stimulate a response • Either volatile or water soluble • Emma reads when I point to the below • “So what do pheromones have to do with SEX?”

10. Offspring Survival • The importance (and dangers) of parents • The apparently happiest family ever

11. Gametes and Gonads • Female eggs • Ovary (usually ovaries) • Oviduct • Uterus • Male sperm • Testicle (usually testis) • Vas efferens • Vas deferens • Seminal vesicle

12. Flatworm Honey Bee

13. Humans • Female • Male

14. Female Reproductive Anatomy

15. The book says you have to know… • The hymen is a thin tissue that partly covers the vagina • Women have erectile tissues • Juan reads when I point to the below. • “Do erectile tissues mean girls can get erections?”

16. Mammary Glands • Epithelial tissues secrete milk • Fatty or adipose tissue forms is most of the mass of the breast of a when not lactating • Men have nipples and mammary glands too

17. Male Reproductive Anatomy

18. More book stuff • The Leydig cells are scattered between the seminiferous tubules • Guys have a prepuce similar to how girls do • Some mammals have a bone called a baculum • Marissa asks when the below is pointed to • “Why do guys have scrotums, when that puts their gonads at risk of being harmed?”

19. Human Sexual Response • Vasoconjestion-increased blood flow through arteries of the area • Myotonia-increased muscle tension • 4 stages • Excitement • Plateau • Orgasm • Resolution

20. Hormones and the Reproductive Organs • Gametogenesis- the production of gametes in mammals • Oogenesis-the development of a mature ova • Cytokenises is not equal • Cells divide a definite number of times • as “resting periods” • Spermatogenesis-the development of mature sperm cells • Cytokenises is equal • Cells divide indefinately • Works continuously

22. Female Reproductive Cycles and Hormones • Ovarian Cycle-has 2 phases • Follicular Phase • Luteal Phase • Uterine or Menstrual Cycle- has 3 Phases • Proliferative Phase • Secretory Phase • Menstrual Flow Phase

23. HEAD FOR THE HILLS, SHE’S COMING! • Menopause-the ceasing of ovulation and menstruation • An common phenomenon that may be linked to evolution • The biker formerly known as “Doc” asks the below when it’s pointed to • “How could not being able to reproduce be a benefit to a species?”

24. Male Reproductive Sex Hormones and the Organs Involved

25. Humans and Placental Mammals get Pregnant

26. Pregnancy or Gestation • Term length depends on size of the animal an maturity of the young at birth • Pregnancy begins with the conception after coitus • Conception-the fertilization of the egg by the sperm • Conception can occur 3-5 days after intercourse

27. Pregnancy in Humans • Can be divided into three month trimesters • 1st trimester-main period of organogenesis or the creation of the organs • A heart beat can be heard by the fourth week • 2nd trimester-the fetus begins to be active and can be felt “kicking” • 3rd trimester-the fetus grows to its birth weight and size

28. Labor and Delivery

29. Immune Tolerance • George says the below right now • “What’s immune tolerance got to do with zygotes and fetuses?”

30. Contraception and Abortion • Natural planning-planning around the ovulation cycle to avoid the times with great • Abortion-the termination of a pregnancy • Happens in 1/3 of all pregnancies • Can be done surgically or with a drug if in the first 7 weeks

31. Modern Technology • Ultrasounds can be used to see babies in the womb (if a baby’s in the womb and it doesn’t make a sound it is it there?) • A.R.T. or Assisted Reproductive Technology can be used to give pregnancy to a sterile individual