1. AP Biology 2005-2006 Animal Reproduction Chapter 46.

2. AP Biology 2005-2006 Sexual & asexual reproduction  Asexual  offspring all have same genes (clones)  no variation  Sexual  gametes (sperm & egg)  fertilization  mixing of genes  variation

3. AP Biology 2005-2006 Parthenogenesis  Development of an unfertilized egg  honey bees  drones = males produced through parthenogenesis  haploid  workers & queens = females produced from fertilized eggs  diploid queenworkerdrone

4. AP Biology 2005-2006 Different strokes… parthenogenesis in aphids “lesbian” lizards sex-change in fish gay penguins

5. AP Biology 2005-2006 Hermaphrodites flat worm earthworms mating  Having functional reproductive system of both sexes

6. AP Biology 2005-2006 Fertilization  Joining of egg & sperm  external  usually aquatic animals  internal  usually land animals

7. AP Biology 2005-2006 Development  External  development in eggs  fish & amphibians in water  soft eggs= exchange across membrane  birds & reptiles on land  hard-shell amniotic eggs  structures for exchange of food, O 2 & waste  sharks & some snakes  live births from eggs  Internal  placenta  exchange food & waste  live birth

8. AP Biology 2005-2006 Adaptive advantages?  What is the adaptive value of each type of sexual reproduction  number of eggs?  level of parental of care  habitat?

9. AP Biology 2005-2006 Human Reproduction

10. AP Biology 2005-2006 Reproductive hormones  Testosterone  from testes  functions  sperm production  2° sexual characteristics  Estrogen  from ovaries  functions  egg production  prepare uterus for fertilized egg  2° sexual characteristics LH & FSH testes or ovaries

11. AP Biology 2005-2006 Sex hormone control in males Hypothalamus Pituitary Testes Body cells GnRH FSH & LH testosterone

12. AP Biology 2005-2006  Sperm production  over 100 million produced per day!  ~2.5 million released per drop! Male reproductive system

13. AP Biology 2005-2006 Male reproductive system  Testicles  produces sperm & hormones  Scrotum  sac that holds testicles outside of body  Epididymis  where sperm mature  Vas deferens  tubes for sperm to travel from testes to penis  Prostate, seminal vesicles, Cowper’s (bulbourethal) glands  nutrient rich fluid to feed & protect sperm  buffer to counteract acids in vagina

14. AP Biology 2005-2006 Male reproductive system  Testes & epididymis  sperm production & maturation  Glands  seminal vesicles, prostate, bulbourethal  produce seminal fluid = nutrient-rich seminiferous tubule sperm spermatocytes

15. AP Biology 2005-2006 Spermatogenesis Epididymis Testis Coiled seminiferous tubules Vas deferens Cross-section of seminiferous tubule Spermatozoa Spermatids (haploid) 2° spermatocytes (haploid) 1° spermatocyte (diploid) Germ cell (diploid) MEIOSIS II MEIOSIS I

16. AP Biology 2005-2006 Female reproductive system

17. AP Biology 2005-2006 Female reproductive system  Ovaries  produces eggs & hormones  Uterus  nurtures fetus; lining builds up each month  Fallopian tubes  tubes for eggs to travel from ovaries to uterus  Cervix  opening to uterus, dilates 10cm (4 inches) for birthing baby  Vagina  birth canal for birthing baby

18. AP Biology 2005-2006 Female reproductive system

19. AP Biology 2005-2006 LH FSH estrogen progesterone lining of uterus egg developmentovulation = egg release corpus luteum 07142128days Menstrual cycle Hypothalamus Pituitary Ovaries Body cells GnRH FSH & LH estrogen

20. AP Biology 2005-2006 Egg maturation in ovary  Corpus luteum  produces progesterone to maintain uterine lining

21. AP Biology 2005-2006 Female hormones  FSH & LH  release from pituitary  stimulates egg development & hormone release  peak release = release of egg (ovulation)  Estrogen  released from ovary cells around developing egg  stimulates growth of lining of uterus  lowered levels = menstruation  Progesterone  released from “corpus luteum” in ovaries  cells that used to take care of developing egg  stimulates blood supply to lining of uterus  lowered levels = menstruation

22. AP Biology 2005-2006 Oogenesis Meiosis 1 completed during egg maturation Meiosis 2 completed triggered by fertilization ovulation  What is the advantage of this development system?

23. AP Biology 2005-2006 Fertilization

24. AP Biology 2005-2006 Fertilization  Joining of sperm & egg  sperm head enters egg

25. AP Biology 2005-2006 Cleavage  Repeated mitotic divisions of zygote  1st step to becoming multicellular  unequal divisions establishes body plan  different cells receive different portions of egg cytoplasm & therefore different regulatory signals

26. AP Biology 2005-2006 Cleavage  zygote  morula  blastula  establishes future development

27. AP Biology 2005-2006 Gastrulation  Establish 3 cell layers  ectoderm  outer layers  skin, nails, teeth, nerves  mesoderm  blood, bone & muscle  endoderm  inner lining  digestive system ectoderm mesoderm endoderm

28. AP Biology 2005-2006 Neurulation  1st organ to form is notochord & nerve chord  develop into nervous system Neural groove Notochord Neural tube

29. AP Biology 2005-2006 Organogenesis Umbilical blood vessels Chorion Amnion Yolk sac Allantois Fetal blood vessels Maternal blood vessels Bird embryo Mammalian embryo Placenta

30. AP Biology 2005-2006 Placenta  Materials exchange across membranes

31. AP Biology 2005-2006 Human Embryonic Development

32. AP Biology 2005-2006 Sex determination XY XX Testes Y SpermZygote Ovum Sperm Ovum X X X Indifferent gonads SRY No SRY Ovaries (Follicles do not develop until third trimester) Seminiferous tubules Develop in early embryo Leydig cells

33. AP Biology 2005-2006 Human fetal development  Day 1: 1 st cleavage  1 cell becomes 2 (2-cell stage)  Day 2: 2 nd cleavage  4-cell stage  Day 3: 6-12 cell stage  can test at this stage for genetic diseases if done by IVF  Day 4: 16-32 cell stage  solid ball of cells = morula

34. AP Biology 2005-2006 Ovulation to implantation

35. AP Biology 2005-2006 Human fetal development  Day 5:  solid morula develops into hollow, fluid-filled blastula  embryo will develop from the inner cell mass, or embryonic disc  Day 6 -7:  blastocyst attaches to the endometrium (uterine lining) & burrows in: implantation  blastocyst starts to secrete HCG = human chorionic gonatotropin  stimulates estrogen & progesterone to prevent menstrual flow  causes "morning sickness" in some women...  pregnancy test measures the amount of this hormone!

36. AP Biology 2005-2006 Human fetal developmental  Days 10 - 14:  pregnancy becomes established  fluid filled amniotic cavity starts to form  yolk sac starts to form  will make blood cells, germ cells  embryo starts to form from embryonic disc  chorion (placenta) starts to form  At the end of this stage, a woman will have just missed her period! Day 14

37. AP Biology 2005-2006 Human fetal developmental  Days 15 - 21:  emergence of the vertebrate body plan  primitive streak starts to form  the site of gastrulation (formation of 3 tissue layers = ecto, endo, and mesoderm)  neural groove begins to form  future spinal cord & brain  somites begin to form  bands of tissue that will become muscles & bones  pharyngeal arches begin to form  future face, neck, mouth, nose

38. AP Biology 2005-2006 Human embryonic developmental Day 24  Week 3 - Week 8 = embryo  development of all organ systems  Day 22: the heart begins to beat Day 28 Week 4

39. AP Biology 2005-2006 Human embryonic development  embryo showing tail & limb buds

40. AP Biology 2005-2006 Human embryonic development  beginning of the eye can be seen, as well the bulging heart & the umbilical cord

41. AP Biology 2005-2006 Human embryonic development  lens of the eye can be seen forming, the mass of the heart bulging from the chest, & the beginnings of the finger rays

42. AP Biology 2005-2006 Human fetal development 7 weeks4 weeks

43. AP Biology 2005-2006 Human embryonic development

44. AP Biology 2005-2006 Human embryonic development  beginning of the ear is clearly seen note the bend of the elbow joint has begun, the fingers are forming and toes are beginning to bud off the foot

45. AP Biology 2005-2006 Human embryonic development  Note the formation of the nose, eyelids, ear flap & well defined toes & fingers 50–60 days (8 weeks) Both knee & elbow are visible. Embryo has formed most of basic organ systems & will spend remainder of development in “fetal” period. Organs grow, mature, & begin to learn their respective functions

46. AP Biology 2005-2006 Human fetal development  Day 52:  first brain waves can be detected  weeks 4-8 is when all major organ systems of body are formed & when most teratogens have greatest effect Week 8

47. AP Biology 2005-2006 Human fetal development 10 weeks

48. AP Biology 2005-2006 Human fetal development  At 15 weeks the embryo begins to take on more of a typical baby's form & the attachment of umbilical cord can be clearly seen Week 15

49. AP Biology 2005-2006 Human fetal development  Week 9 - week 40 = fetus  after 12 weeks or so, the baby's development is largely "finished"  some exceptions: brain & lung development Week 16

50. AP Biology 2005-2006 Human fetal development  The fetus just spends much of the 2 nd & 3 rd trimesters just growing …and doing various flip-turns & kicks inside amniotic fluid Week 20

51. AP Biology 2005-2006 Human fetal development  24 weeks (6 months; 2nd trimester) fetus is covered with fine, downy hair called lanugo. Its skin is protected by a waxy material called vernix

52. AP Biology 2005-2006 Human fetal development  30 weeks (7.5 months) umbilical cord

53. AP Biology 2005-2006 Getting crowded in there!!  32 weeks (8 months) The fetus sleeps 90-95% of the day & sometimes experiences REM sleep, an indication of dreaming

54. AP Biology 2005-2006 Birth Hormone induction positive feedback

55. AP Biology 2005-2006 Intestine Placenta Umbilical cord Wall of uterus Vagina Cervix Birth (36 weeks) Bladder

56. AP Biology The end of the journey!