1. Sexual reproduction
Two parents- each parent contributes half of its genetic information to the offspring
Maintains variety within a species

2. Review- chromosomes are found in pairs called homologous chromosomes
Diploid chromosomes number – both chromosomes from each pair are present in the cell

3. Monoploid chromosome number- only one chromosome from each pair is present in the cell.
(also called haploid chromosome number)

4. Meiosis Occurs only in the gonads
Produces gametes with a monoploid (n) chromosome number

6. Gonads- specialized structures where meiosis occurs
Testes
ovaries

7. Gametes- specialized cells with a monoploid chromosome number
Sperm
Ova (eggs)

8. Spermatogenesis Is Meiosis in the male Produces sperm
Occurs in the testes
All sperm have an adaptation that allows them to travel to the egg

9. Oogenesis Is meiosis in the female Produces eggs (ova)
Occurs in the ovaries

10. Sperm + Egg= Zygote n+n=2n
Fertilization
Sperm + Egg= Zygote
n+n=2n

11. External fertilization
Occurs outside the female body
Fish and amphibians
Many ova are released at one time.
Sperm are deposited over the eggs

12. Internal fertilization
Occurs inside the female body
Sperm is introduced into the moist environment of the female reproductive tract where they unite with the ovum (egg)

15. External development Occurs outside the female body Amphibians, fish:
develop in water
Yolk provides food
Little or no parental care
Birds, reptiles:
fertilization occurs before shell forms
yolk, nest

18. Internal development
Occurs inside female body

19. Non-placental mammals
platypus

20. Marsupials
Have an underdeveloped placenta

21. Give birth to premature offspring that climb in a pouch (marsupium) to finish their development

23. External development vs. Internal development
worksheet

24. Human Reproduction
Males-

25. Testes- male gonads; lie outside the body in the scrotum where the temp. is 2-4o lower than body temp.
Sperm produced continuously from puberty to old age.
Epididymis- coiled tube that stores and nourishes sperm; flagellum (tail) grows

26. Vas deferens- sperm duct that leads from the epididymis to the urethra
Seminal vesicles, Cowper’s gland & prostate- all produce fluid which becomes semen

29. Females

30. Ovaries – female gonads; where ova are produced; 1 ½ inches long; in lower abdominal cavity
Fallopian tubes (oviduct)- lead from ovary to uterus * Fertilization occurs here!!!!
Uterus- pear-shaped organ, thick walled, muscular. Development of fetus occurs here

31. Cervix- muscular ring between uterus and vagina
Vagina- muscular tube leading from uterus to outside the body. (birth canal)

34. Menstrual cycle
Female releases one gamete (ovum) once a month from puberty to menopause
Controlled by hormones
4 stages

35. Follicle stage
Follicle – structure in the ovary where the ovum is prepared to be released
Last days
FSH (follicle stimulating hormone) from the pituitary causes the formation of the follicle
Follicle begins to release the hormone estrogen which shuts off the production of FSH
Estrogen triggers the thickening of the uterine lining

37. Ovulation Ovum is released from the ovary
Luteinizing hormone (LH)- triggers ovulation

40. Corpus luteum
Follicle fills with yellow cells that produce a hormone called progesterone
Progesterone maintains the thickening of the uterine lining in case fertilization occurs

41. Menstruation
Uterine lining is shed if fertilization does not occur

42. Fertilization Occurs in the upper part of the Fallopian tube
Sperm and egg unite; diploid chromosome number is restored

48. Embryonic Development
Embryology- study of embryo development

49. Terms in embryology Zygote – fertilized egg
Cleavage- rapid cell division in zygote; division of zygote into a solid ball of cells
Morula- solid ball of cells

50. morula

51. Blastula- hollow ball of cells-
differentiation begins in this stage of development
Differentiation – cells become specialized in structure and function

52. blastula

53. Gastrula- formation of 3 primary germ layers

54. gastrulation

57. 3 primary germ layers
These 3 layers of cells develop into the structures of the new organism

58. endoderm Inner most layer of cells Produces digestive tract
Respiratory system
Liver
Pancreas
thyroid

59. mesoderm Middle layer of cells Produces Skeleton Muscles
Circulatory system
Excretory system
gonads

60. ectoderm
Outer layer of cells
Produces
Nervous system
Skin
Hair

61. Life in the uterus Placenta forms from embryonic cells
Exchange of materials between mother and fetus
Mother sends oxygen, food, antibodies to fetus
Fetus sends waste to mother (Carbon dioxide, urea)
No exchange of blood

62. Umbilical cord forms between the 4th and 8th week

65. Amnion- membrane that holds amniotic fluid (protection)
Umbilical cord- connects placenta to fetus

71. 4 weeks

72. 8 weeks

73. 3 months

74. 6 months

75. 6 months

78. Multiple births
More than one child born at a time

81. Identical Twins
One egg is fertilized by one sperm and in early embryonic development the morula splits into two individual group of cells.
Can identical twins be two different genders?

82. Fraternal twins
Two eggs are fertilized by two different sperm

83. Caesearn section
Surgery is performed to remove the fetus from the uterus.