If a mutant organism used mitosis to produce gametes, what would be the result of mating with a wildtype partner?

Question

A.  Progeny would be quadraploid, and almost certainly nonviable.
B.  Progeny would be triploid, and almost certainly nonviable.
C.  Progeny would be normal -- this is a common occurrence in some phyla.
D.  The resulting progeny would be identical twins.


Clarify Question
What is the key concept addressed by the question?

What type of thinking is required?


Gather Content
What do you already know about gametes? What other information is related to the question?

Choose Answer
Given what you now know, what information 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.  Progeny would be triploid, and almost certainly nonviable.


Clarify Question
What is the key concept addressed by the question?
     · This question is asking about the effects of a mutation in a gamete.

What type of thinking is required?
     · Analyze level:
       o This is an analyze question because you have to break mutant and wild type gametes into their component pieces to understand how they function.


Gather Content
What do you already know about gametes? What other information is related to the question?
     · Ploidy refers to the number of sets of chromosomes. 
     · Haploid cells have one set of chromosomes, diploid cells have two sets of chromosomes, triploid cells have three sets of chromosomes, etc.
     · Mitosis makes clones of existing cells. A diploid cell gives rise to a diploid clone via mitosis.
     · The process of gamete formation normally occurs via meiosis. Meiosis yields four haploid cells from one diploid cell.
     · Usually fertilization combines a haploid egg and a haploid sperm to make a diploid offspring.


Choose Answer
 Given what you now know, what information is most likely to produce the correct answer?
     · Normally, meiosis produces haploid (n) gametes. When two haploid gametes fuse, the result is a diploid (2n) embryo.
     · If a gamete arose through mitosis, it would be diploid. Fusion with a normal haploid gamete would produce a triploid cell.


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?
     · Analyze level:
       o Answering this question correctly depended not only on distinguishing between mitosis and meiosis, but on your ability to break down, or analyze, the nature of the resulting cells. If you got an incorrect answer, did you remember that cells produced via mitosis are diploid, or that cells produced by meiosis are haploid? Did you have trouble breaking down the concept of gametes to determine the correct answer?