Lesson 9. Differentiation, Specialization, Development, and Growth

Estimated Time: 1 period

Objective

Track the development of the fetus once the egg had been fertilized, focusing on differentiation of cells

EQ: What happens after fertilization?

Bridge

Base your answers to the questions on the information below and on your knowledge of biology.

The diagram below represents some stages in the life cycle of humans. The numbers in the diagram represent various processes in the cycle.

Identify the process occurring at 1 and 2. State how processes 1 and 2 affect the amount of genetic information provided by a parent to its offspring.

______

______

Identify the process at 3. State how process 3 affects the amount of genetic information an offspring receives.

______

______

Mini Lesson

Share out answers to the bridge

So at this point in our movie, the egg has been fertilized, but that does not automatically mean baby. Right now we have one cell with a complete set of genetic information, half from each parent. But we are made of more than one cell, in fact we have trillions. And our cells gather together to make tissues and our tissues added together make organs and those organs arrange into organ systems, each with a specific job to do. How does that happen?

Expectations for Work Period: Watch the next 3 sections of “Life’s Greatest Miracle”. There is more to the video but I stop it there…. The only thing left is her giving birth. Answer the questions.

Work Period

  1. What is the combined mission once the egg and sperm join?
  2. What is the first job of the zona after fertilization?
  3. Where is the fertilized egg (zygote) going?
  4. What happens inside of the zygote as it moves towards the uterus? How long does it take to get to the uterus?
  5. What 2 things does the zygote have to do once it reaches the blastocyst stage?
  6. Why is the blastocyst in danger once it implants in the uterus? How does it counteract this attack?
  7. What milestone event happens about 2 weeks after fertilization? What is the process called? Where does it occur in humans?
  8. What will the layers formed in the hollow ball form into?
  9. Describe what is happening in the process of gastrulation.
  10. What will the lower layer of cells form?
  11. What will the middle layer of cells form?
  12. What will the top layer of cells form?
  13. What controls the specialization (also called differentiation) of cells in your body? How does it do this?
  14. What organic molecule builds your body? Give 2 examples of these molecules and the job that they do in the body.
  15. How do cells talk to each other so they know what to grow into?
  16. What controls the sex of the embryo? How does it do this?
  17. Since you cannot determine sex in the early stages of development through reproductive parts, how COULD you determine the embryo’s sex really early?
  18. How do genes send out the messages they need to direct development?
  19. When does the embryo become a fetus?
  20. Where does the nutrition for the baby come from? What 2 structures aid in getting these nutrients to the developing fetus?
  21. Does the blood between the baby and the mother ever mix?
  22. What organ is working within weeks of development?
  23. What organs do not start to function until later in development?

Summary

Answer the EQ

Closing

Many mothers and fathers engage in activities that are detrimental to a developing baby. At what point in the reproductive process would…..

Activities of the father damage the fetus?

Activities of the mother do the MOST damage to the fetus?

Independent Practice

Regents questions