Reproduction Eggs Sperm are made in Gonads Female

Reproduction

Eggs & Sperm are made in Gonads Female Gonad - Ovaries Male Gonad - Testes Sperm and Eggs are haploidthat means they have half the Number of chromosomes (add that)

Step 1: When an egg is fertilized by a sperm, it is called a zygote. SPERM EGG n + n= half of the amount of genetic material n = 2 n ZYGOTE

Step 2: Zygote Divides • Zygote divides by mitosis • The repeated mitotic cell division is called Cleavage. • Zygote divides into 2, 4, & then 8 Cells

Step 3: • The zygote keeps dividing & makes a ball of cells, called a Morula

Step 4: • From a Morula it becomes a Blastula • When it becomes hollow it is called a Blastula • **This is what a stem cell is***

Step 5: Gastrulation • Differentiation of tissues occurs • 3 Germ layers are made • Invagination- the cells fold into each other • This is called a gastrula

3 Layers have names: Ectoderm Mesoderm Endoderm

3 Germ Layers (outside layer) Becomes the Nervous System, skin, hair and nails Endoderm (inside layer) digestive tract and respiratory tract Ectoderm Muscles, circulatory system, Mesoderm skeletal system, excretory (middle Layer) system, and glands

• An embryo develops in the uterus, and gets nourishment from a placenta • The exchange of nutrients, respiratory gases, and waste diffuse through the placenta

Placenta

Prenatal Care/Pregnancy • Environmental factors can harm the embryo/fetus • EX: use of drugs, alcohol, tobacco, or other toxins

• Life in the Womb Part 1

STOP

Menstrual Cycle • The release of a mature egg from a follicle • Occurs ~28 days, and lasts for ~7 days • Starts with Puberty, and ends with menopause

4 stages of Menstrual Cycle • 1. Menstruation (flow phase) • 2. Follicle Stage • 3. Ovulation • 4. Corpus Luteum (Luteal Phase)

1. Menstruation • When: Day 1 - Day 6 • Hormone: Increase in Follicle Stimulating Hormone • Menstrual flow begins • Shedding of uterine lining and blood

2. Follicle Stage • When: Day 7 - 14 • Hormone: Follicle Stimulating Hormone stimulates an egg to become mature • Follicle Stimulating Hormone thickens the uterine lining

3. Ovulation • When: Day 14 • Hormone: Estrogen stops the production of FSH • Estrogen stimulates the release of Luteinizing hormone • Mature egg is RELEASED

4. Corpus Luteum Stage • “Luteal Phase” • When: Day 15 - Day 28 • Hormones: Luteinizing and Progesterone • Luteinizing hormone (LH) stimulates the Corpus Luteum to develop

• Corpus Luteum is the part of the follicle that remains in the ovary • It stimulates estrogen and progesterone • It disintegrates and leaves a scar on the ovary

Hormones Progesterone Thickens Uterine Lining Luteinizing Stimulates the corpus luteum to develop Follicle Stimulating Hormone Stimulates an egg to become mature Estrogen Stimulates the release of Luteinizing hormone