Chapter 29 Objectives
 Development and Inheritance 

1. Be able to explain how and when sex is determined.

2. Explain how twins can be conceived.

3. Explain when the blastocyst is formed and its structure.

4. Be able to identify the major derivatives of the three germ layers.

5. Identify the four embryonic membranes and their functions.

6. Be able to draw and understand a fourteen day old embryo.

7. Compare the maternal and fetal placentas.

8. Identify the three stages of labor.

9. List the functions of the hormones:  estrogen, human chorionic gonadotopin (hCG), and oxytocin.

Chapter 29 -Take a Quiz

1. Sex is determined when
        a. the baby is born
        b. after an ultrasound
        c. at fertilization
        d. the three germ layers develop

2. Identical twins develop from:
        a. two oogonia that divide by mitosis
        b. two secondary oocytes
        c. two sperm and one secondary oocyte
        d. one secondary oocyte and one sperm

3. As mitotic divisions occur in the fertilized egg, the egg is moving through the 
    passageway known as the:
        a. birth canal
        b. internal os
        c. uterine tubes
        d. fertilization membrane

4. Identify the mismatched structure and description below.
        a. blastocele -  a fluid filled cavity
        b. morulla - a ball of cells
        c. inner cell mass - destined to become the human embryo
        d. trophoblast - the outer layer of cells that implants in the uterine lining.
        e. all of the above

5. Match the germ layers in Column A with their components in Column B.

           A                                                                     B

        Ectoderm                                             ___cartilage and bone
                                                                   ___nervous system
                                                                   ___epidermis
       Endoderm                                            ___lining of digestive tract
                                                                   ___lining of urethra and vagina
                                                                   ___lining of body cavities
        Mesoderm                                          ___blood and bone marrow
                                                                  ___chorion

6. The embryonic membrane known as the bag of waters is the:
        a. amnion
        b. yolk sac
        c. chorion
        d. allantois 

7. The embryonic membrane that develops into part of the umbilicus is the:
        a. amnion
        b. yolk sac
        c. chorion
        d. allantois 

8. The placenta that resembles blood sinuses is the _______________________ component.  The placenta that resembles fingerlike projections of blood capillaries is the _____________________ component.

9. The third stage of labor involves
        a. the birth of the body
        b. the dilation of the cervix
        c. the expulsion of the placenta
        d. the rupture of the amnion

10. Identify a function of  the hormone, hCG.
        a. is the basis for pregnancy test
        b. causes ovulation
        c. is responsible for the three stages of labor
        d. fertilization