You notice that in your aquarium, previously full of undoubtedly male fish, one is laying eggs. Upon a bit of research, you find out that the species of fish you purchased is a sequential hermaphrodite. Which of the following is true?

Question

A.  One of the male fish underwent protandry and became a female.
B.  One of the male fish fertilized its own eggs.
C.  Since the fish are hermaphrodites, one of the male fish laid eggs and another will likely fertilize them.
D.  The fish have parthenogenesis, therefore their eggs do not have to be fertilized to be viable.
E.  The fish have protogyny, which allows the males to lay eggs.

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 different reproductive strategies? 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

A.  One of the male fish underwent protandry and became a female.


Clarify Question
What is the key concept addressed by the question?
     · This question is asking about the reproductive strategy that is exhibited by a male fish that reproduces as a female fish later in its life.

What type of thinking is required?
     · Apply level:
       o You are being asked to take what you already know and use, or apply, it to the reproductive pattern of a fish.

Gather Content
What do you already know about different reproductive strategies? What other information is related to the question?
     · Hermaphroditism refers to the existence of active male and female reproductive organs (testes and ovaries) in the same body.
     · Sequential hermaphroditism occurs when an individual is able to reproduce as one gender at one point in life, and then can reproduce as another gender at a later point in life.
     · Protandry is a form a sequential hermaphroditism in which an individual reproduces as a male first, then reproduces as a female later.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
     · If it was apparent that an individual was male and not female, the individual could not be a hermaphrodite as well.
     · If only male fish were present, there would be no eggs to fertilize. A female fish must have been present to produce the eggs.
     · Protogyny refers to a type of sequential hermaphrodite in which the individual reproduces as a female first, then later as male. This is the opposite of what is occurring in this example. This also does not allow a male to lay eggs.
     · Parthenogenesis does occur in fish, but eggs still must come from a female, and the individuals in this example were male.
     · The events in this example can only be explained by protoandry. The individuals were initially male, but were later able to reproduce as females.

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?
     · Apply level:
       o Answering this question correctly depended on your ability to use reproductive strategies in a new situation. If you got an incorrect answer, did you remember that hermaphroditism can be sequential, or that protandry occurs when the individual reproduces as a male first, then reproduces as a female later? Did you have trouble identifying the different reproductive strategies to determine the correct answer?