OVERVIEW Reproduction is the creation of new individuals from existing ones A population can exceed its finite life spans by reproduction Adaptations of animal form and function will contribute to their reproductive success

46.1: Both Asexual and Sexual Reproduction Occur in the Animal Kingdom 2 Modes of Animal Reproduction Asexua l: genes of new individuals come directly from one parent -relies on mitotic cell division Sexual : new individuals created by the fusion of gametes to form zygotes - Increases genetic variability of offspring - Higher chance of reproductive success

Asexual Reproduction of Sea Anemone Earthworms Mating Sexually

Mechanisms of Asexual Reproduction Fission: Parent separates into two or more individuals of equal size Budding: New individuals arise from outgrowths of existing ones Fragmentation: Body breaks down into multiple pieces-some or all of these pieces develop into adults - it requires regeneration of the lost body parts

Hydra Budding Video

Fission in AmoebaYeast Cells Budding Starfish using fragmentation

Reproductive Cycles and Patterns Reproductive cycles are controlled by hormonal and environmental cues Parthenogenesis: process in which egg develops without fertilization Temperature Rainfall Lunar Cycles Parthenogenesis in Daphnia Eggs

Cont.. Hermaphroditism: each individual has male and female reproductive systems - some hermaphrodites self- fertilize Sequential hermaphroditism: individual reverses its sex during its lifetime Lizard hermaphrodites Sex reversal in bluehead wrasse

46.2 Fertilization Depends on Mechanisms that help sperm meet eggs of same species 2 types of fertilization -External: eggs shed by female are fertilized by sperm in external environment External Fertilization frog -Internal: egg and sperm unite in female body Fertilization requires environmental cues Inside female body

Ensuring the Survival of Offspring Internal fertilization: produces less zygotes than external - but survival rate higher for internal fertilization Parental care and protection of embryos results in few offspring by internal fertilization Male giant water bug carrying eggs

Gamete Production and Delivery Reproductive systems produce gametes and make them available to gametes of the opposite sex. Simplest Reproductive systems do not have gonads (gamete producing organs) Complex systems- accessory tubes and glands to protect/nourish gametes Complex flatworm reproductive system

46.3 Reproductive Organs Produce and Transport Gametes: focus on humans Female Reproductive Anatomy External: human female has vulva, labia minora, labia majora, and clitoris Internal: Vagina connected to uterus, which connects to two oviducts; 2 ovaries (female gonads) have follicles containing egg cells Mammary glands present in male and female but only function in female Female Reproductive System

Male Reproductive System External structures: scrotum and penis - testes (male gonads), are in cool environments in scrotum - testes have hormone producing cells and seminiferous tubules leading to tip of penis(epididymis, vas deferens, ejac. duct, urethra )

Male Reproductive System

Human Sexual Response 2 physiological reactions in both sexes: vascongestion-filling of tissue with blood myotonia- increased muscle tension 4 phases of response: -excitement -plateau -orgasm -resolution

46.4 In Humans and other mammals, a complex interplay of hormones regulates gametogenesis Oogenesis- female form of gametogenesis (production of gametes) Spermatogenesis- male form Meiosis is essential to oogenesis and spermatogenesis Differences: - oogenesis: cytokinesis is unequal-produces large ovum; spermatogenesis: starting cells become 4 sperms - oogenesis: cyclic; spermatogenesis: constant/continual

The Reproductive Cycles of Females Menstrual(Uterine) cycle: proliferative and secretory phase - caused by ovarian cycle Female reproductive cycle is one integrated cycle Reproductive cycle dependent on secretion of GnRH, FSH, and LH

Hormonal Control of Male Reproductive System Androgens (steroid hormones) from testes cause primary and secondary sex characteristics in males Androgen secretion and production controlled by hypothalamic and pituitary hormones

46.5In humans and other placental mammals, an embryo grows into a newborn in the mother’s uterus Pregnancy (Gestation): carrying one or more embryos in the uterus Human pregnancy: 38 weeks Pregnancy time, in other species, correlates with body size and maturity of young at birth

Conception, Embryonic Development and Birth After meiosis and fertilization of egg, zygote becomes blastocyst Human pregnancy: 3 trimeters - Baby develops with time - Urine contractions (parturition) causes birth 3 stages of birth: dilation of cervix, expulsion, delivery of placenta

Human Fetal Development Timeline

Three stages of Labor

Mother’s Immune Tolerance of Embryo and Fetus Half embryo genes are from father: foreign to mother’s body Trophoblast and placenta: protect embryo from rejection in mother’s body - release signal molecules - break down tryptophan - induce “death activator” protein (FasL)

Contraception and Abortion Contraception: prevention of pregnancy Methods of contraception prevent -release of mature gametes -fertilization -implantation

Modern Reproductive Technology Helps -Detect any problems with developing embryo before birth -People have children through in vitro fertilization: oocytes mixed with sperms and incubated Ultra Sound

Works Cited "Female Infertility." Mayo Clinic. Mayo Foundation for Medical Education and Research. Web. 23 Apr "Human Development." ROHAN Academic Computing Web. 25 Apr "Science Clarified." Birth Web. 24 Apr