The most common form of gene therapy involves inserting a normal gene into cells that contain a defective version of the gene. In order to use gene therapy to prevent a man from passing a defective gene on to future generations, you should try to insert normal copies of the gene into

Question

A.  blood cells.
B.  germ-line cells.
C.  somatic cells in the testes.
D.  bone marrow cells.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

  Gather Content
  · What do you know about fertilization? How does it relate to the question?
Consider Possibilities
    · What other information is related to the question? Which information is most useful?

  Choose Answer
  · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?  

  Reflect on Process
  · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
 

Answer 1

B.  germ-line cells.

Clarify Question
  · What is the key concept addressed by the question?
        o The question asks about the transfer of genetic information to the next generation.
· What type of thinking is required?
        o You are being asked to apply your knowledge of fertilization to explain which types of cells produce gametes.
· What key words does the question contain and what do they mean?
        o Passing a defective gene on to future generations – gametes are used to transfer genetic material from one generation to the next.

  Gather Content
  · What do you know about fertilization? How does it relate to the question?
        o Gametes pass genetic information from one generation to the next.  If you want to correct a defective gene so it cannot be passed on, it would need to be done in gametes.
 
Consider Possibilities
    · What other information is related to the question? Which information is most useful?
        o Gametes are produced by meiosis in specific cells in the body.  This does not happen in somatic cells like blood cells or bone marrow cells.

  Choose Answer
  · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?  
        o Gametes are produced in germ-line cells in the testes and ovaries.  If gene therapy is done on these cells, then the gametes they produce would contain the fixed gene and this would be passed on to future generations.

  Reflect on Process
  · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked you to apply your understanding of gamete production to predict which cells would pass genetic changes on to the next generation. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that germ-line cells produce gametes?  Did you realize that the changes would need to be made in the gametes to be passed on to the next generation?  Did you think that changes in somatic cells like blood and bone marrow cells could be passed on to the next generation?