AIM: What is the goal of Differentiation?

I. Differentiation’s ultimate goal… An embryo with many different types of cells

II. Stem Cells Stem cells are embryonic cells that can turn into any type of cell in the body

III. How can stem cells help us? Can be used to make any type of cell that needs to be replaced in our bodies

IV. Are stem cells only embryonic? No, there are some adult stem cells, but they don’t have the potential to become every kind of cell

Why is the use of stem cells so controversial? They are often taken from fetuses. Opponents believe that you are killing a life.

V. Girls Secondary Sex Characteristics Hips widen Pubic Hair Breast development Due to the hormones estrogen and progesterone.

VI. Boys Secondary Sex Characteristics Voice Deepens Facial Hair Muscular Development Pubic Hair Due to the hormone Testosterone.

VII. Hormonal Regulation of the Testes: Beginning at puberty, the pituitary gland secretes FSH & LH. The rising levels of these hormones stimulate the testes to produce testosterone. Testosterone stimulates the production of sperm.

The process of a sperm joining an egg is called ____________________. *STUDY QUESTIONS:   Fertilization The process of a sperm joining an egg is called ____________________. 2. Is the following sentence true or false? A fertilized egg is known as a zygote. _________ Fertilization TRUE

Early Development Match each term with its definition. Term Definition 3. __ Morula a. Organ that nourishes the embryo 4. __ Blastocyst b. Name of embryo when it is a solid ball of about 64 cells 5. __ Implantation c. Name of morula when it is a hollow ball of cells 6. __ Gastrulation d. Membrane that surrounds and protects the embryo 7. __ Amnion e. Process in which the blastocyst attaches to the wall of the uterus 8. __ Placenta f. Process of cell migration that produces three cell layers B C E F D A

9. Is the following sentence true or false 9. Is the following sentence true or false? The first few cell divisions take place in the Fallopian tube. ____________ TRUE 10. After eight weeks of development, the embryo is called a(an) FETUS 11. Is the following sentence true or false? Most of the major organs and tissues are fully formed by the end of three months of development. TRUE – 1ST TRIMESTER ALSO: UMBILIC CORD, MUSCLES, REFLEXES, AMNION

Later Development 13. What changes occur during the last three months of fetal development?   __________________________________________________ FETUS DOUBLES IN SIZE, LUNGS FORMING, DREAMS, PREMATURE IF BORN BEFORE 8TH MONTH

Childbirth   14. Is the following sentence true or false? The process of childbirth begins when the hormone calcitonin is released from the posterior pituitary gland. _________ 15. The series of rhythmic contractions of the uterine wall that force the baby out through the vagina is known as _____________. 16. What stimulates the production of milk in the breast tissues of the mother? ______________________ Multiple Births 17. If two eggs are released and fertilized by two different sperm, ____________ twins result. 18. If a single zygote splits apart to produce two embryos, _______________twins result. FALSE -OXYTOCIN LABOR OXYTOCIN FRATERNAL IDENTICAL