04 Aug Define the term blastocyst.

Purpose

View the film “Life’s Greatest Miracle” and trace the path of a sperm from its production in the male to fertilization of an egg and subsequent development and birth of a human infant. (CO-1, 2, 3, 5)

Directions

• Access the online film by PBS entitled “PBS Nova The Miracle of Life (1983) [Duration 57:11] (Links to an external site.).” You may also search the Internet for the title of the film if this link is broken or will not open for you.
• Allow sufficient time to view the film. It is almost 1 hour in length.
• Answer the following 20 questions pertaining to the film as you watch.
  1. As the narrator indicates, making a human is no simple feat. As embryos, we all started off as a single cell. How many cells ultimately complete the human body?
  2. In what way(s) does bacterial DNA reproduction look different from that of humans? How does this benefit or provide advantages to humans?
  3. How many new sperm does a man produce per second? Per day? In his lifetime?
  4. Suggest a reason why a male produces so many sperm.
  5. What is the name of the process that results in an egg or sperm cell? How does this process generate genetic variety, ensuring no 2 sperm or egg cells are genetically identical?
  6. Why is genetic diversity a good thing for the human race?
  7. When do males create sperm cells? When do women create egg cells?
  8. Once in the fallopian tubes, what is the window of time within which an egg cell must be fertilized or else it will die?
  9. The typical ejaculate is approximately 1 teaspoon in volume. How many sperm cells is this estimated to contain?
  10. Is the vaginal environment hospitable to sperm? Why or why not?
  11. In what way(s) is the female responsible for helping sperm reach their ultimate goal, the egg cell?
  12. How does a sperm cell get through the outermost barrier of an egg cell, the zona pellucida?
  13. Even after an egg is fertilized by the sperm, it is estimated that what percentage of all fertilized eggs fail to develop?
  14. Define the term blastocyst.
  15. Describe the process of gastrulation.
  16. If all the cells in our bodies contain the same DNA, why don’t all cells look and function exactly alike? Feel free to use specific examples from the film.
  17. How does a gene get turned on?
  18. At what point in development is an embryo referred to as a “fetus, and how big is it at this point?”
  19. What crucial events take place during the last trimester of development?
  20. Write a short paragraph which emphasizes something new you have learned from the film.