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 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?

#Question id: 5321

#Unit 11. Evolution and Behavior

Biologists now routinely test for homology between genes in different species. If genes are determined to be homologous, how are they related to each other?

#Question id: 5322

#Unit 11. Evolution and Behavior

A current view of how the human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter ________.

#Question id: 5323

#Unit 8. Inheritance Biology

An X-linked recessive gene produces red-green color blindness in humans. A woman with normal color vision whose father was color-blind marries a color-blind man. What is the probability that their son will be color-blind?

#Question id: 5324

#Unit 8. Inheritance Biology

In eusocial insects, males develop from unfertilized eggs while females develop from fertilized eggs. The ultimate consequence of this difference is that

#Question id: 5325

#Unit 8. Inheritance Biology

Cystic fibrosis is caused by a recessive lethal gene and can be detected by an excess concentration of chloride in sweat. A normal man whose sister has cystic fibrosis, his normal wife whose brother has cystic fibrosis. What is chance of cystic fibrosis in their child?

#Question id: 5326

#Unit 8. Inheritance Biology

The recessive allele located on heterozygous locus present on X-chromosome in female is conclude as