Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh Edition Solomon Berg Martin Chapter 48 Reproduction

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Asexual reproduction A single parent endows its offspring with genes identical to its own –Energy efficient –Most successful in a stable environment

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Means of asexual reproduction Budding –Part of the parent’s body grows and separates from the rest of the body Fragmentation –The parent’s body breaks into pieces –Each piece can grow into a new animal Parthenogenesis –An unfertilized egg develops into an adult

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Asexual reproduction by budding

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Sexual reproduction Offspring produced by fusion of two gametes –Ovum –Sperm A fertilized egg (zygote) forms Promotes genetic variety and is adaptive in an unstable environment

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction External fertilization Mating partners typically release eggs into the water simultaneously Internal fertilization Male delivers sperm into the female’s body Hermaphroditism Single individual produces eggs and sperm

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human male reproductive system Testes –Housed in the scrotum –Contain the seminiferous tubules, where sperm production takes place –Interstitial cells secrete testosterone –Sertoli cells produce signaling molecules and a fluid that nourishes sperm cells

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human male reproductive system, cont. Sperm –Stored in the epididymis and vas deferens –During ejaculation, sperm pass from the vas deferens to the ejaculatory duct and into the urethra

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human male reproductive system, cont. Penis –Three columns of erectile tissue –Two cavernous bodies –One spongy body that surrounds the urethra Erectile tissue becomes engorged with blood and causes erection

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Male reproductive system

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Spermatogenesis Takes place in the seminiferous tubules Spermatogonia divide by mitosis Head of a sperm consists of the nucleus and an acrosome, containing enzymes that help penetrate the egg

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Spermatogenesis in the seminiferous tubules

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Spermatogenesis

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Sperm pass in sequence through Seminiferous tubes of the testes Epididymis Vas deferens Ejaculatory duct Urethra

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Structure of a mature sperm

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Endocrine regulation of reproduction in the human male Testosterone establishes and maintains –Primary sex characteristics –Secondary sex characteristics

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Internal structure of the penis

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Endocrine regulation of reproduction involves the Hypothalamus –GnRH Pituitary gland –FSH and LH Testes –Testosterone –ABP and inhibin

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Principal male reproductive hormones

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Regulation of reproduction in the male

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human female reproductive system Ovaries –Produce gametes –Steroid hormones estrogen and progesterone Fertilization takes place in the oviducts

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Female reproductive system

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human female reproductive system, cont. Uterus –Incubator for the embryo –Endometrium thickens each month –Cervix extends into the vagina

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human female reproductive system, cont. Vagina –Lower part of the birth canal –Vulva includes the labia majora, labia minora, vestibule, clitoris, and mons pubis

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Female reproductive system, anterior view

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human female reproductive system, cont. Breasts –Function in lactation –Prolactin stimulates milk production –Oxytocin stimulates milk ejection from the alveoli into the ducts

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Development of a human ovum Oogenesis takes places in the ovaries Oogonia differentiate into primary oocytes –Primary oocyte and granulosa cells make up a follicle

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Oogenesis

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Development of a human ovum, cont. As the follicle grows –Connective tissue cells form a layer of theca cells –Primary oocyte undergoes meitosis, giving rise to a secondary oocyte and a polar body

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Development of follicles in the ovary

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Development of a human ovum, cont. During ovulation –The secondary oocyte is ejected and enters an oviduct to be fertilized –The part of the remaining follicle develops into a corpus luteum

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Endocrine regulation of reproduction Preovulatory phase –GnRH stimulates the pituitary to secrete FSH and LH –Estrogen stimulates endometrium development –LH stimulates final maturation of the follicle and ovulation

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Endocrine regulation of reproduction, cont. Postovulatory phase –LH promotes development of the corpus luteum –The corpus luteum secretes progesterone and estrogen –If fertilization does not occur, the corpus luteum degenerates, hormone levels fall, and menstruation occurs

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Principal female reproductive hormones

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Feedback mechanisms in endocrine regulation of female reproduction

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Physiological changes that occur during sexual response Sexual excitement Plateau Orgasm Resolution

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human fertilization Fusion of secondary oocyte and sperm to form a zygote Embryo implants in the uterus hCG is the hormone that maintains the corpus luteum Estrogen and progesterone –Secreted by corpus luteum (first trimester) and then by placenta

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Fertilization

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Events following fertilization

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Human birth process Several hormones, including estrogen, oxytocin, and prostaglandins regulate parturition Labor –Divided into three stages –The baby is delivered during the second stage

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Contraception Hormonal methods, such as oral contraceptives Intrauterine devices Condoms and contraceptive diaphragms Sterilization (vasectomy or tubal ligation)

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Sterilization

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Abortions Spontaneous miscarriages occur without intervention Induced abortions –Therapeutic performed to maintain the mother’s health, as birth control, or when the embryo is thought to be grossly abnormal

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Common sexually transmitted diseases (STDs) Chlamydia Gonorrhea Syphilis Pelvic inflammatory disease (PID) Genital herpes HIV

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Endocrine regulation of reproduction involves the Hypothalamus –GnRH Pituitary gland –FSH and LH Testes –Testosterone –ABP and inhibin

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Some types of endocrine signaling

Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 48 Reproduction Major chemical groups of hormones