Chapter 46 Reading Quiz 1.In ____ reproduction, two haploid ____ fuse to form a ____. 2.Which tubes within the male produce sperm? 3.Which female hormone induces uterine contractions?

1. Distinguish between sexual and asexual reproduction, including relevant terms. Sexual  the fusion of gametes (n) to form a zygote (2n) - gametes are formed by meiosis - ovum (unfertilized egg) - spermatozoon (male gamete) Asexual  new individuals whose genes are from one parent - relies on mitosis

2. Define budding, fission, fragmentation, and regeneration. Why are these considered reproduction? Fission  separation of a parent into 2 individuals of equal size (sea anemone) Budding  new individuals splitting off from an existing individual (sponges) Fragmentation  the breaking of an individual into several pieces (sponges) Regeneration  the regrowth of lost body parts (some sea stars)

3. Describe how reproductive cycles and patterns vary extensively among animals. Cycles are controlled by hormonal & environmental cues May alternate between sexual & asexual Parthenogenesis  development of egg without fertilization Hermaphroditism  produce both male and female gametes - sequential hermaphroditism  reverses sex (some fish, oysters)

4. Distinguish between internal and external fertilization and define pheromones. Internal  fertilization occurs inside the female’s body - requires more cooperative mating behaviors External  fertilization occurs in the environment - occurs almost exclusively in moist environments - environmental cues and pheromones trigger release of gametes Pheromones  chemical signals between organisms of the same species - easily dispersed in environment

5. Describe mammalian reproduction. a. briefly overview the male & female anatomy Male  external: scrotum & penis internal: testes, glands, & ducts - seminiferous tubules  sperm form - interstitial cells  produce testosterone - epididymis  tubules, store sperm - vas deferens  duct at ejaculation - seminal vesicles  secrete fluid (energy for sperm & prostaglandins for uterine contraction) - prostate  produces fluid, balances acidity of vagina - bulbourethral glands  fluid for acidity

Female  Ovaries, ducts, and chambers External  clitoris & labia Ovaries with eggs, all formed at birth, develop in follicles, which produce estrogens Every menstrual cycle one follicle matures and releases the egg Ovulation  egg is expelled from follicle, remaining tissue forms the corpus luteum, which secretes progesterone (which maintains uterine lining) and more estrogen - if egg is not fertilized, corpus luteum degenerates - egg is expelled and drawn into uterus with cilia Uterus  thick muscular organ to accommodate a fetus 

Continued… Endometrium  the inner uterine lining, richly supplied with blood vessels Cervix  neck of uterus, opens into vagina Vagina  thin-walled chamber, birth canal Hymen  membrane that covers vaginal opening and is broken during activity Bartolin’s glands  glands that lubricate the vagina Mammary glands (not part of reproductive system, but important in reproduction)  small sacs of epithelial tissue that secrete milk

b. describe how spermatogenesis & oogenesis differ (page 984) Spermatogenesis  the production of mature sperm cells - continuous & prolific - each ejaculation contains million Oogenesis  the development of ova; between birth & puberty, the egg cells enlarge and follicles grow - ovum & polar bodies result after meiosis

c. describe the male & female interplay of hormones Males  androgens, primary & secondary sex characteristics, also sex drive and aggressiveness - controlled by the hypothalamus and anterior pituitary Females  estrous cycle: non-primate animals, endometrium reabsorbed - menstrual: average 28 days 1. Menstrual flow 2. Proliferative: regeneration & thickening 3. Secretory: continued endometrium development Hormones next slide

6. Describe the development between conception and birth. 1.Conception  sperm meets in oviduct, cleavage begins in 24 hours, becomes blastocyst and reached uterus in 3-4 days 2.Implantation  egg meets uterine lining within the week, 2-4 weeks begins to obtain nutrients 3.Placenta  functions in gas exchange, nutrient transfer, and waste removal 

Continued.. 1.First trimester  organogenesis - after 8 weeks all organs are present - fetus 5cm long - embryo secretes hormones to signal presence - human chorionic gonadotropin (hCG) maintains progesterone & estrogen levels to prevent menstruation 2.Second trimester  rapid growth, 30 cm - placenta secretes progesterone, pregnancy obvious 3.Third trimester  rapid growth, 50 cm - maternal organs become compressed & displaced - labor is induced: estrogen, oxytocin, progesterone - Parturition  birth and then placenta is expelled 4.Lactation  decreased levels of progesterone, increased prolactin (after 2-3 days), then oxytocin

5 weeks 14 weeks 20 weeks

7. Briefly overview reproductive immunology. Embryo does have foreign markers; why the mother doesn’t reject this foreign body is not completely understood The trophoblast is a protective layer between mom & baby that prevents tissue contact White blood cell suppression Miscarriage issues 

8. Describe the various contraception options. 1.Keep eggs and sperm apart - rhythm method (10-20% failure) - condoms, diaphragms, cervical caps, sponges, spermicidal (fails <10%) 2.Prevent implantation of embryo - intrauterine device (IUD) 3.Prevent release of mature eggs & sperm a. chemical contraception (fails <1%) - blocks LH release, progestin prevents ovulation - estrogen inhibits FSH so no follicles develop b. sterilization  snip snip! 100% effective

9. Describe how modern technology offers solutions for some reproductive problems. 1.Ultrasound 2.Maternal blood sampling 3.Amniocentesis  fluid withdrawn 4.Chorionic villus sampling  bit of placenta analyzed for problems 5.In vitro fertilization