TLS Online TPP Program

#Question id: 12428


Flycatcher birds that migrate from Africa to Europe feed their nestlings mostly with moth caterpillars. The data presented show the mean dates of egg laying, hatching, and fledging of flycatcher young, and the 1980 and 2000 peak mass of caterpillars.

Why are ecologists  concerned about the shift in  date from May 28 in  1980 to May 15 in  2000 of the caterpillar peak mass?

#Unit 10. Ecological Principles
  1. The  caterpillars will  eat  much of  the  foliage of  the  trees where flycatchers nest, and  their  nests will  be more open to predation.
  2. The earlier hatching of caterpillars will compete with other insect larval forms on which the flycatchers also feed their young.
  3. The flycatcher nestlings in 2000 will miss the peak mass of caterpillars and may not be as well fed.
  4. The flycatchers will have to migrate sooner to match their brood-rearing season with the time of caterpillar peak mass.
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TLS Online TPP Program

#Question id: 4657

#Unit 11. Evolution and Behavior

 Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ?

TLS Online TPP Program

#Question id: 4658

#Unit 11. Evolution and Behavior

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution?

TLS Online TPP Program

#Question id: 4659

#Unit 3. Fundamental Processes

Many bacterial responses are controlled by two component regulatory systems. What will happen at the high concentration of glutamine and at the low concentration of glutamine?

a) At high concentrations glutamine binds to a sensor domain of NtrB conformational change in the protein that inhibits its histidine kinase activity

b) NtrC phosphorylation takes place causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

c) At the same time, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers

d) At low concentrations of glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain

Which of the following given combination is correct?

TLS Online TPP Program

#Question id: 4660

#Unit 3. Fundamental Processes

Two-component system regulating response to low Gln,

a) Glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain in NtrB

b) glutamine binds to a sensor domain of NtrB, causing a conformational change in the protein that inhibits its histidine kinase activity, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers.

c) Activated transmitter domain of NtrB that transfers the γ-phosphate of ATP to a histidine residue (H), this phosphohistidine then transfers the phosphate to an aspartic acid residue (D) in the NtrC protein

d) This causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 4661

#Unit 3. Fundamental Processes

In bacteria two components regulatory systems contain a domain can have function such as controlling the direction in which the bacterium swims in response to a concentration gradient of nutrients is known as

TLS Online TPP Program

#Question id: 4662

#Unit 3. Fundamental Processes

Transcriptional activation by Pol II initiates transcription, polymerase pauses after transcribing fewer than 100 nucleotides due to the action of the elongation inhibitor such as