Life’s greatest miracle


· Guide Questions to answer as you view “Life’s Greatest Miracle.” (This video was produced in 2001.)

· (This video can also be viewed online at

· Please submit the answers to this on 1 whole sheet of pad paper Feb 9, Tuesday (Individual work).

Chapter 1. Passing On Your DNA

1. Why is sexual reproduction more advantageous than cloning?

Chapter 2. The Egg’s Journey

2. Describe the path the egg takes after being released from the ovary.

3. The video states that an egg will survive only a few hours if not fertilized. More recent information suggests that an egg will survive at least 24 hours and perhaps as long as 48 hours if not fertilized. How does that fact influence the most fertile time when couples are attempting to avoid pregnancy using the rhythm method?

Chapter 3. The Sperm’s Journey

4. What kind of obstacles will a sperm encounter once it enters the female?

5. Where in the female reproductive tract does fertilization of the egg occur?

Chapter 4. The First Two Weeks

6. Why would more than 50% of all fertilized eggs not survive? What kind of problems could a fertilized egg encounter?

7. How do identical twins form?

8. How does the blastocyst prevent the mother’s immune system from destroying the developing embryo?

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Nerve impulse transmission

Confused about nerve impulse transmission? Check out the following links:

  1. Review neuron structure
  2. Animation of nerve impulse transmission (shown in class)
  3. Good explanation of the phenomenon
  4. Saltatory conduction vs transmission in unmyelinated axons (shown in class)
  5. Communication at the synapse (shown in class)
  6. Another animation on synaptic transmission (slightly more detailed)

Schematic of an Action Potential

Diagram from (