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.
_________________________________________________________________________________
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Identify the process at 3. State how process 3 affects the amount of genetic information an offspring
receives.
_________________________________________________________________________________
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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.
http://www.youtube.com/watch?v=y2yIUeXtTdw&feature=BFa&list=PLF1797686D94C4CEF
http://www.youtube.com/watch?v=OdNj7d1FK-Y&feature=related
Work Period
1.
2.
3.
4.
What is the combined mission once the egg and sperm join?
What is the first job of the zona after fertilization?
Where is the fertilized egg (zygote) going?
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