TLS Online TPP Program

#Question id: 7279


X chromosome number alone is the primary sex determinant in normal drosophila because:

#Unit 5. Developmental Biology
  1. The X chromosome contains genes encoding transcription factors that activate the critical gene in Drosophila sex determination.
  2. Male and female parts and their sex-linked characters are activated by Y chromosome.
  3. The number of X chromosome is greater than number of Y chromosome.
  4. Only X chromosome is active, Y chromosome is inactive.
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TLS Online TPP Program

#Question id: 4995

#Unit 11. Evolution and Behavior

It has been found that certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This is evidence in support of the claim that

TLS Online TPP Program

#Question id: 4994

#Unit 11. Evolution and Behavior

In certain motile prokaryotes, dozens of different proteins comprise the motor that powers the prokaryotic flagellum. The motor has a complicated structure, and its various proteins interact to carry out its function. Based on Darwinʹs explanation for the existence of human eyes, how would he probably have explained the existence of such motors?

TLS Online TPP Program

#Question id: 4993

#Unit 11. Evolution and Behavior

If the prokaryotic flagellum developed from assemblages of proteins that originally were not involved with cell motility but with some other function instead, then the modern prokaryotic flagellum is a(n)

TLS Online TPP Program

#Question id: 4992

#Unit 11. Evolution and Behavior

The existence of the phenomenon of exaptation is most closely associated with which of the following reasons that natural selection cannot fashion perfect organisms?

TLS Online TPP Program

#Question id: 4991

#Unit 11. Evolution and Behavior

Which of these fly organs, as they exist in current fly populations, best fits the description of an exaptation?

TLS Online TPP Program

#Question id: 4990

#Unit 11. Evolution and Behavior

Fly species W, found in a certain part of the island, produces fertile offspring with species Y. Species W does not produce fertile offspring with species X or Z. If no other species can hybridize, then species W and Y