Biology 105 Chapter 50: Reproduction Pages Chapter 50: Reproduction Pages

Student Outcomes Compare the advantages of asexual and sexual reproduction Describe the structure and function of the organs of the male reproductive system Describe the structure and function of the female reproductive system Compare the advantages of asexual and sexual reproduction Describe the structure and function of the organs of the male reproductive system Describe the structure and function of the female reproductive system

Student Outcomes Trace the development of a human ovum until it is fertilized Describe the process of fertilization and early development. Compare the advantages/disadvantages of methods of birth control. Trace the development of a human ovum until it is fertilized Describe the process of fertilization and early development. Compare the advantages/disadvantages of methods of birth control.

Reproduction Types –Asexual One parent, identical to parent, –Sexual Two parents. Combine genetic information - Get potential of better offspring. Types –Asexual One parent, identical to parent, –Sexual Two parents. Combine genetic information - Get potential of better offspring.

Asexual Budding- small part of parent separates and forms a new individual Fragmentation - parent breaks into several - each able to regenerate Parthenogenesis - unfertilized egg is able to develop. Budding- small part of parent separates and forms a new individual Fragmentation - parent breaks into several - each able to regenerate Parthenogenesis - unfertilized egg is able to develop.

Sexual Internal Fertilization-takes more energy External Fertilization-chance event, faster Hermaphrodite Internal Fertilization-takes more energy External Fertilization-chance event, faster Hermaphrodite

Human Male Reproduction Spermatogenesis - formation of sperm cells Spermatogonia (2N) - primary spermatocytes (2N)-secondary spermatocytes (N)-spermatids(N) - mature sperm (N) Spermatogenesis - formation of sperm cells Spermatogonia (2N) - primary spermatocytes (2N)-secondary spermatocytes (N)-spermatids(N) - mature sperm (N)

Sperm Structure –Head Acrosome nucleus –Midpiece - contains the mitochondria –Tail (flagellum) –(little cytoplasm) Held in Scrotum - sac that descends/ascends from body to maintain a cooler body temperature. Structure –Head Acrosome nucleus –Midpiece - contains the mitochondria –Tail (flagellum) –(little cytoplasm) Held in Scrotum - sac that descends/ascends from body to maintain a cooler body temperature.

Development and Release Seminiferous tubules - epididymis (sperm are stored and mature - vas deferens (duct)- urethra Semen - 3ml - about 200,000,000 sperm Prostate gland secretes fluid of enzymes and slightly basic Seminiferous tubules - epididymis (sperm are stored and mature - vas deferens (duct)- urethra Semen - 3ml - about 200,000,000 sperm Prostate gland secretes fluid of enzymes and slightly basic

Human Female reproduction Ovaries - produce the female sex cell Oogenesis- oogonia - primary oocytes(2N)- secondary oocyte Ovulation - ovum is released from the ovary. Menstruation - if fertilization does not occur, the lining of the uterus and unfertilized egg are released Ovaries - produce the female sex cell Oogenesis- oogonia - primary oocytes(2N)- secondary oocyte Ovulation - ovum is released from the ovary. Menstruation - if fertilization does not occur, the lining of the uterus and unfertilized egg are released

Lactation Production of milk in response to pregnancy. (estrogen and progesterone promote increase in breast size) Colostrum -protein and lactose stimulated by the hormone prolactin Production of milk in response to pregnancy. (estrogen and progesterone promote increase in breast size) Colostrum -protein and lactose stimulated by the hormone prolactin

Menstrual Cycle Usually 28 days on average –Preovulatory phase - 2 weeks –Ovulation - 14th day –Postovulatory phase - 2 weeks Usually 28 days on average –Preovulatory phase - 2 weeks –Ovulation - 14th day –Postovulatory phase - 2 weeks

Hormones in charge GnRH (gonadotropin releasing hormone) released from hypothalamus stimulates anterior pituitary to release FSH and LH. This stimulates a few egg follicles to develop. Only one will continue to develop. Estrogen prevents further release of FSH and LH. Estrogen continues to rise and promotes a surge in LH causing ovulation

Fertilization Joining of egg and sperm. Most fertile time is 14 days from 1st day of menstrual flow. High Pregnancy time is between days if cycle is regular. Occurs in oviduct and is at the 32 cell stage when implanted in the uterine wall. Joining of egg and sperm. Most fertile time is 14 days from 1st day of menstrual flow. High Pregnancy time is between days if cycle is regular. Occurs in oviduct and is at the 32 cell stage when implanted in the uterine wall.

Preventing pregnancy Oral contraceptives Injectable contracptives Intrauterine device - common worldwide Spermicides Diaphragm Condom Rhythm Oral contraceptives Injectable contracptives Intrauterine device - common worldwide Spermicides Diaphragm Condom Rhythm

Preventing Pregnancy Cont Withdrawal Sterilization –Tubal Ligation –Vasectomy Chance Withdrawal Sterilization –Tubal Ligation –Vasectomy Chance

Abortions Types –Spontaneous (miscarriages), usually due to abnormal development –Induced - deliberate Suction (first 3 months) RU-486 prevents implantation of embryo –Therapeutic - to protect the mother’s life or if embryo is grossly abnormal. Types –Spontaneous (miscarriages), usually due to abnormal development –Induced - deliberate Suction (first 3 months) RU-486 prevents implantation of embryo –Therapeutic - to protect the mother’s life or if embryo is grossly abnormal.

Fertility Males are fertile from puberty to death, although sperm become less viable with age Females are fertile from puberty (Menarche) to Menopause. Eggs become less viable in the 30’s Males are fertile from puberty to death, although sperm become less viable with age Females are fertile from puberty (Menarche) to Menopause. Eggs become less viable in the 30’s

Infertility The process of not achieving pregnancy after one year of unprotected sex. (1 in 6 couples). Will need medical assistance to achieve pregnancy. –Male Infertility –Female Infertility –Combination –Unknown The process of not achieving pregnancy after one year of unprotected sex. (1 in 6 couples). Will need medical assistance to achieve pregnancy. –Male Infertility –Female Infertility –Combination –Unknown

Male Infertility Low sperm count Low motility Improper sperm development Low sperm count Low motility Improper sperm development

Female Infertility No egg released Female body inhospitable to sperm Fertilized egg cannot implant Endometriosis Low body fat No egg released Female body inhospitable to sperm Fertilized egg cannot implant Endometriosis Low body fat

Infertility treatments-males Maintain proper temperature for sperm production Sperm sample are ‘washed’ and implanted directly into woman Maintain proper temperature for sperm production Sperm sample are ‘washed’ and implanted directly into woman

Infertility treatments-females Hormone treatment to regulate cycle Production and release of more mature eggs Sperm are implanted directly Egg are harvested and combined with sperm in a petri dish and then the developing zygote is implanted. Hormone treatment to regulate cycle Production and release of more mature eggs Sperm are implanted directly Egg are harvested and combined with sperm in a petri dish and then the developing zygote is implanted.

Combined Treatments-ART Artificial Insemination (AI) In vitro fertilization (IVF)- –Involves both hormone treatment for female and AI –May use cryopreservation Artificial Insemination (AI) In vitro fertilization (IVF)- –Involves both hormone treatment for female and AI –May use cryopreservation