Asexual Reproduction in a Sea Anemone

Overview: Doubling Up for Sexual Reproduction The two earthworms in this picture are mating Each worm produces both sperm and eggs, which will fertilize –And in a few weeks, new worms will hatch Figure 46.1

Sexual Behavior in Parthenogenetic Lizards (all female); adults are haploid (a) The female on the back induces development of an egg during critical times of the hormone cycle

Sex Reversal in a Sequential Hermaphrodite Females (yellow) Male (Blue) All are born female and the largest complete lives as males

Many different types of animals –Exhibit parental care to ensure survival of offspring Figure 46.6

The Release of Eggs and External Fertilization

Reproductive Anatomy of a Parasitic Flatworm

Reproductive Anatomy of the Human Male

Seminiferous tubules (left), sperm in semen (right)

Structure of a Human Sperm Cell Contains an enzyme that helps penetrate the egg

Reproductive Anatomy of the Human Female

Menstrual Cycle (mensis = month) - lasts approx. 28 days

Follicle Phase (lasts days) starts when hypothalamus re- leases GnRH that stimulates the pituitary gland FSH stimulates cell division in the follicle, a layer of cells that sur- rounds the immature egg. These cells supply nutrients to the egg and secrete estrogen.

Hormones of the Hypothalamus and Pituitary Glands Nerve cells that release hormones into the blood

Ovary Follicle Ovum

Ovulation (last 3-4 days) when a woman is most likely to get pregnant occurs when LH and FSH levels peak follicle releases the egg into the fallopian tube

Oogenesis

Ovulation

Luteal Phase (lasts about 14 days) After ovulation the structure is now called the corpus luteum. It secretes large amount of estro- gen and progesterone to maintain the lining of the uterus until the egg is fertilized.

Menstruation (approx 5 days) occurs when the endometrium starts to slough off; the lining of the uterus and ruptured blood vessels are discharged through the vagina

The Reproductive cycle of the Human Female

Hormonal Control of the Testes

Mechanisms of Some Contraceptive Methods Figure Male Female Method Event Method Production of viable sperm Production of viable oocytes Vasectomy Combination birth control pill (or injection, patch, or vaginal ring) Sperm transport down male duct system Ovulation Abstinence Condom Coitus interruptus (very high failure rate) Sperm deposited in vagina Capture of the oocyte by the oviduct Abstinence Tubal ligation Spermicides; diaphragm; cervical cap; progestin alone (minipill, implant, or injection) Sperm movement through female reproductive tract Transport of oocyte in oviduct Meeting of sperm and oocyte in oviduct Morning-after pill (MAP) Union of sperm and egg Implantation of blastocyst in properly prepared endometrium Birth Progestin alone

Formation of the Zygote and Early Postfertilization Events

Placental Circulation

Human Fetal Development

Hormonal Induction of Labor

Sperm are made in the _______ _______ and mature in the _______. The function of the prostate gland is to... Fertilization occurs in the...

Ovulation occurs when the levels of _____ and _____ peak. Give an example of negative feed- back using the hormones of the menstrual cycle. A woman is most likely to get pregnant at which time of the month?

Describe the path of a sperm cell from where it is made to where it fertilizes the egg in a female. Hint: There are 7 structures involved.