Life's Greatest Miracle KEY

Teacher Notes: This program is not appropriate for younger viewers. The video is narrated by John Lithgow, shows some partial nudity and childbirth at the end. A permission form is included, I strongly recommend previewing the video before showing it to your class.

I do use this program in my senior anatomy class because it is a fantastic resource for the discussion of tissues and how the body plan is governed by the action of genes. The program shows how chromosomes pair and exchange genes, how these genes are turned on to direct the development of tissue layers. The three main tissue layers are discussed with regard to body plan (ectoderm, mesoderm, endoderm). The program also show how a single cell pinches inward during gastrulation to create the three germ layers.

Another video "From Conception to Birth" focuses on the changes in the mother's body, this one is mainly about the embryo. This video is probably more appropriate for younger viewers, as many of the scenes are cleverly edited and some things are implied rather than shown.

http://www.pbs.org/wgbh/nova/miracle/.

Note: This program may not be suitable for all viewers. | Download Permission Form

1. DNA is very good at ____________making copies of itself_____

2. Why is sexual reproduction more advantageous than cloning? _________ offspring are different from parents _________

3. How many new sperm are created every day? _______100 million _________

4. During meiosis, what happens to the matching X-shaped chromosomes? ______cling together and exchange material__________________

5. How is the egg pushed along within the Fallopian tube? ___cilia or muscular contractions __

6. To fertilize the egg, sperm encounter several obstacles, what is the last one they encounter before they penetrate the egg? ___zona ___

7. The blatocyst must do two things to survive, it must break out of the zona and what else ? _____ find a source of nutrients _____

8. Two weeks after conception, the cells organize themselve into an ____embryo_____, a process called gastrulation.

9. The three layers of cells created during gastrulation are destined for three different functions. Describe what each will become:

Bottom Layer ________digestive tract___________ Middle Layer _____muscles, bones__________ Top Layer ________nervous tissue_________

10. Genes turn on and off to make proteins. Collagen is a protein that makes tendons and bones, keratin makes hair. Hemoglobin in the blood has what job? ________carry oxygen ___________

11.An embryo with two X chromosomes will become a ___girl___. An embryo with the XY combination will become a ___boy_______.

12. Two months after fertilization, the embryo is called a _______fetus ______________

13. What structure is used to gather blood and nutrients from the mother's blood and pass it to the umbilical cord? ___ placenta___

14. At the end of pregnancy, the baby is growing myelin around its neurons. This growth increases its need for what nutrient? __ fat __

15. Why is it harder for human babies to be delivered than other animals? ___ shape of pelvis, size of head ____