#Question id: 12242
#Unit 10. Ecological Principles
#Question id: 1563
#Unit 4. Cell Communication and Cell Signaling
A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to ________.
#Question id: 13129
#Unit 10. Ecological Principles
Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation and on egg-to-adult survival. From a large source population, they randomly assigned eggs to three experimental populations of size N, equal to 20, 60, and0100. For later generations, they collected N eggs from each population and moved them into identical vials that co0ntained f2re0sh me4d0ium. Th6e0y coun8te0d the number of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by scoring alleles at several polymorphic loci and expressed as the average number of alleles at those loci. The results are summarized in Figure 1 and Figure 2 below.
Based on Figure 1, which of the following best describes the change in genetic variation over time?
#Question id: 10238
#Unit 10. Ecological Principles
The diagram below shows the frequency distribution of two closely related bird species based on their resource use in sympatric. Which one of the following phenomena most appropriately explains the change in frequency distributions of species 1 and 2 in the figure given above?
#Question id: 11343
#Unit 2. Cellular Organization
In the liver, which type of GLUT transports glucose out of hepatocytes when liver glycogen is broken down to replenish blood glucose?