Author Question: A large proportion of archaeans are extremophiles, so called because they inhabi (Read 791 times)

geoffrey

  • Hero Member
  • *****
  • Posts: 880
A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on the primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?
A) Among themselves, they should share relatively few ancestral traits, especially those that enabled ancestral forms to adapt to extreme conditions.
B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.
C) They should contain genes that originated in eukaryotes that are the hosts for numerous species of bacteria.
D) They should currently be undergoing a high level of horizontal gene transfer with non-extremophilic archaeans.



penguins

  • Hero Member
  • *****
  • Posts: 903

Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The average adult has about 21 square feet of skin.

Did you know?

Walt Disney helped combat malaria by making an animated film in 1943 called The Winged Scourge. This short film starred the seven dwarfs and taught children that mosquitos transmit malaria, which is a very bad disease. It advocated the killing of mosquitos to stop the disease.

Did you know?

Lower drug doses for elderly patients should be used first, with titrations of the dose as tolerated to prevent unwanted drug-related pharmacodynamic effects.

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

Cucumber slices relieve headaches by tightening blood vessels, reducing blood flow to the area, and relieving pressure.

For a complete list of videos, visit our video library