1. Human Reproduction Sex and Disease Human reproduction

2. This is NOT sex education  Having sex can cause disease called STD (sexually transmitted disease) –HIV infection –Genital herpes –Syphilis –Gonorrhea

3. Herpes

4. Syphilis

5. Gonorrhea

6. Safe Sex  _____ ______

7. Human Reproduction Questions  Q. Can the first time someone has sex cause pregnancy?  Q. Which is smaller a sperm cell or an egg?  Q. How do sperm swim? Cilia? Villi? Flagella?

8. Human Reproductive System Female  Oogenesis- egg production  Four eggs are created per month yet only one survives –Three Polar bodies are created –This causes chromosomal shedding  Cytokinesis is lopped sided in oogenesis

9. Human Reproductive System- Male  Meiosis produces sperm in the testicles  Spermatogenesis has equal cytokinesis  The two testicles are in a sac outside the body called the scrotum –The testicles move with temperature –Sperm meiosis takes place below body temperature (Jockey shorts are anti- spermatogenic)

10. Path of Sperm  1. Manufactured in the seminiferous tubules of the two testes  2. Epididymis (Epi, did I miss?)- long coiled tube where sperm matures  3. Vas deferens where sperm is stored  Ejaculation = sperm is released from the vas deferens to the urethra which carries the sperm through the penis

11. Path of an Egg  1. Egg is produced in the ovary  2. The ovary releases an egg through the process called ovulation  3. The egg usually finds it way up the fallopian tube and is carried to the uterus for implanting  Fertilization can occur anywhere along this path

12. EGGS  Q. Are all eggs formed at the birth of the female?  A. Sort of. A female’s ovaries contain about 2 million oocytes at birth, all have begun meiosis and are stopped in prophase these are called primary oocytes  Only a few primary oocytes go into full mitosis –About 400 of the 2 million oocytes become OVA, mature eggs

13. Human Reproduction  Meiosis produces 700,000,000 sperm per day and one egg per month  Egg meets sperm to form a single cell called a Zygote  The zygote becomes an embryo  The embryo becomes a fetus  After nine months (266 days) the fetus becomes a child

14. There only a small difference between man and females  Everyone starts out a as female  In the tenth week the “Y” chromosome on sperm causes a male, without the “Y” the embryo becomes female  Internally- we are set up to go either way –Indifferent gonads can become ovaries or testicles

15. Twins  Identical = same egg and sperm  Fraternal = separate eggs, separate sperms  Can fraternal twins have separate fathers? Be of different races?  What can happen if a identical twin egg doesn’t separate totally?