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Home Q & A Board Biology-Related Homework Help General Biology
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Catc Catc
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6 years ago
In many animals, changes in melatonin secretion patterns trigger seasonal adjustments in behavior or appearance. Explain how melatonin levels affect singing in male songbirds.
 
  What will be an ideal response?

Question 2

Trypanosomes that infect humans are transmitted by:
 
  a. biting insects
  b. contaminated water
  c. contaminated food
  d. aerosols
  e. parasitic worms
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#1
6 years ago
Answer to q. 1

In some male songbirds, long winter nights lead to an increase in melatonin secretion. The rise in melatonin indirectly prevents singing and other courtship behaviors by slowing secretion of the male sex hormone testosterone. As long as the level of testosterone stays low, the bird will not sing. In the spring, there are fewer hours of darkness, so the melatonin level in the bird's blood declines, testosterone rises, and the bird begins to sing.

Answer to q. 2

a
Catc Author
wrote...
#2
6 years ago
Smiling Face with Glasses Feeling super confident now, TY
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