There are two small populations of finches on one of the Galapagos Islands, each feeding on a different size seed. A drought takes place that leaves only production of the larger of the two seed types. Researchers then observe natural selection towards birds with larger beaks and bodies. However, once the rain returned and the production of smaller seeds became more prolific, there was selection towards birds with smaller beaks and bodies. What would be the best interpretation of this observed scenario? A) macroevolution
B) directional selection
C) bottleneck effect

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Describe the function of the endomembrane system? what organelles are involved?

One function of the poly-a tail on eukaryotic mrna sequences is to the mrna be transported from the nucleus to the cytoplasm. prokaryotic mrna also has a poly-a tail. choose the best explanation of the prokaryotic poly-a tail. a. prokaryotic poly-a tails are composed of a different molecular structure compared with eukaryotic poly-a tails. b. prokaryotic poly-a tails have the same functions as eukaryotic poly-a tails, because this process is highly conserved throughout different species. c. prokaryotic poly-a tails aren't important, because prokaryotes don't have nuclei. d. prokaryotic poly-a tails have other functions,because prokaryotes don't have nuclei.