Phylogenetic trees represent hypothesis about the evolutionary relationships among a group of organisms, these relationship based on which character?

#Question id: 953

#Unit 1. Molecules and their Interaction Relevant to Biology

 The degradation of arginine, histidine and proline all lead to the product ________.

#Question id: 12086

#Unit 10. Ecological Principles

The herbaceous plant Achillea lanulosa is widespread in the Northern Hemisphere. Phenotypic variation in the species has been extensively studied along an altitudinal gradient from sea level to over 3,000 meters. In California there is conspicuous variation in  height; alpine plants are only several centimeters tall  while  those in  the San Joaquin Valley may reach a height of 1.8 meters. Adaptation to different local environments also results in variation in physiological processes such as photosynthetic rate, resistance to cold, and the timing of dormancy.

The genetic polymorphism found in Achillea lanulosa is most likely maintained primarily by

#Question id: 12028

#Unit 7. System Physiology – Animal

#Question id: 1434

#Unit 4. Cell Communication and Cell Signaling

A bone tumor sample appears to be heterozygous for a p53 mutation. The most likely explanation for this finding is:

#Question id: 4839

#Unit 8. Inheritance Biology

In Drosophila males there is complete linkage. What is the reason behind this?