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Study Questions for Sex Determination and Differentiation
1. What is an organizational effect?
Describe how the song bird brain
is organized by the relevant hormones. Be specific about which hormones
are involved in the cascade of events. After these organizational events,
how does a male bird learn his song?
2. What is an activational effect?
Describe how maternal behaviors in
mice are activated by hormone interactions. What is the environmental
trigger for nuturing behaviors? Is
nurturing under genetic control?
3. What is a maternal effect?
How is this different from genetic alteration of phenotype? What are the
advantages of a system in which the female can alter offspring via a maternal
effect, compared to hard-wired genetic differences?
4. How does the phenomenon of
sex change in the stoplight parrotfish span the spectrum of male and female
reproductive phenotypes? Describe the mechanisms of sex change (with diag.
of hormone profile) in terms of the principle male and female hormones found
in fish.
5. Discuss the costs
and benefits of polygyny and monogamy in male song birds and the physiological mechanisms underlying
song, courtship, and the propensity for parental care.
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