Which of these is a natural source of pollution? a. rain b. pesticides c. dust storms d. fossil fuels?

Organisms within a population must compete for resources to survive

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.

Closing romer’s gap. what is the significance of the new fossil evidence found in scotland? answer in claim evidence and reasoning