#Question id: 12844
#General Aptitude
#Question id: 1388
#Unit 4. Cell Communication and Cell Signaling
When Lucifer yellow, a small dye, is injected into a neuron of the retina, neighboring neurons become rapidly labeled. If the retina is incubated in dopamine prior to Lucifer yellow injection, only the injected neuron becomes labeled. These findings suggest which of the following?
I. Neurons of the retina communicate via gap junctions.
II. Dopamine is transferred between cells via gap junctions.
III. Dopamine decreases the permeability of gap junctions.
#Question id: 18607
#Unit 13. Methods in Biology
#Question id: 33301
#Unit 1. Molecules and their Interaction Relevant to Biology
#Question id: 13130
#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.
Which process best explains the dynamics of genetic variation observed in this experiment?