1. Sex, Reproduction, & Development

2. Smoking and Pregnancy In The News

3. Types of Reproduction Sexual reproduction –Union of male & female gametes (sex cells) –Each parent supplies half genetic material Asexual reproduction –No union of gametes –Cloning, unless there is mutation

4. Asexual Reproduction Occurs in all 3 domains of life Disadvantage –Genetic sameness means less survival with changing environments –Variability only due to mutation Advantage –Individuals can reproduce

5. Asexual Reproduction

6. Binary Fission Dividing of individual into two Common in: –Archaea –Bacteria –Many protists

7. Asexual Reproduction by Spores Common in fungi –Life cycle with sexual & asexual stage

8. Asexual Reproduction by Budding Occurs in sponges, jellyfish & anemones

9. Asexual Reproduction by Fragmentation Occurs in flatworms & sea stars Fragments regenerate new parts

10. Parthenogenesis Eggs develop without fertilization Some species engage in behaviors simulating mating

11. Sexual Reproduction Prevalent among most vertebrates Common in many invertebrates Zygote –Fusion of haploid egg & sperm cells –Produces diploid cell

12. Hermaphrodite Both male & female in same body Some can reproduce by self-fertilization Forms of hermaphrodite –Simultaneous –Sequential

13. Modes of Fertilization External Fertilization –Female sheds eggs –Male fertilizes eggs after they leave her body

14. Modes of Fertilization Internal Fertilization –Male deposits sperm in or near the female reproductive tract –Eggs are fertilized in female’s body

15. Human Reproduction Sexual with internal fertilization Gonads = reproductive organs –Male – testes –Female –ovaries Other organs transport & receive sex cells Accessory glands facilitate reproduction

16. Production of Sperm Testes –Housed in scrotum –Placement allows for development –Temperature must be lower than body

17. Testes Structure Composed of seminiferous tubules –Site of sperm production (spermatogenesis) –Sperm production triggered by follicle stimulating hormone Spermatogonia give rise to sperm cells

18. Spermatogenesis Spermatogonia undergo mitosis Some daughter cells undergo meiosis

19. Epididymis Site of sperm cell storage –18 hours to 10 days Unused sperm cells are reabsorbed

20. Vas Defrens Long tube from epididymis thru pelvic cavity Loops over urinary bladder Delivers sperm to urethra

21. Accessory Glands Seminal vesicle –Adds fructose to nourish sperm cells –Bicarbonate buffers acidity of urethra & vagina Prostate –Alkaline fluid Bulbourethral glands –Mucus-like alkaline substance –Lubricant for sexual intercourse

22. Penis Cylinders of erectile tissue

23. Female Reproductive System Vagina –Accepts penis & receives sperm External genitals –Vulva –Mons pubis –Labia majora –Labia minora –Clitoris Erectile tissue

24. Ovaries Female gonad Contain primary oocytes –Can develop into eggs

25. Oogenesis One primary oocyte yields in one ovum & three polar bodies

26. Oviducts Ovulation – mature oocyte is released Oocyte enters oviduct Oviducts lead to uterus Oviduct is site of fertilization

27. Uterus Cervix – lower portion opens to vagina Uterus is site of prenatal development Endometrium – inner lining –Nourishing layer for embryo –Shed monthly if no pregnancy occurs

28. Reproductive Cycle

29. Birth Control Methods

35. Sexually Transmitted Diseases

37. Stages of Human Development Zygote – fusion of egg & sperm Embryo –Morula –Blastocyst –Implantation –Gastrulation –Neurulation Fetus

38. Morula 1 cell zygote begins to divide rapidly Mitosis without growth

39. Blastocyst Ball of cells Portion of interior destined to differentiate Cells begin to migrate (morphogenesis)

40. Implantation Approximately 1 week after fertilization Blastocyst secretes enzymes –Digests portion of endometrial wall Nourished by digested uterine cells

41. Implantation Embryo completes implantation Germ layers begin development (first 2) –Ectoderm –Endoderm

42. From Ovulation to Implantation

43. Gastrulation Primary germ layers fully formed Organs & tissues begin development

44. Neurulation Development of hollow nerve cord Neural groove forms

45. Embryo at Four Weeks

46. Fetus All organ systems are formed Growth & development continues

47. Fetus at Five Months

48. Human Fetus Near Full Term

49. Birth is Initiated by Hormones

50. Newborn Physiological Changes Obtains oxygen from environment Placenta no longer the source of nutrients Blood circulation is increased to lungs

51. Placental-Fetal circulation