a biologist was studying two indigenous groups of people from different areas of the world. the first population was from equatorial africa. the second population was from northern europe. the biologist was studying a gene that affects skin color. the biologist examined the gene in 100 people from each population. she kept track of how many different forms ( or alleles ) of the gene she found in each population. the results are in the graph in figure

When the oxygen produced by photosynthetic plants in the water dissolves in the water, which of these is being formed?

How do the sperm cells get from the stigma to the ovules?

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.