The majority of marine organisms are found in coastal regions, rather than the open ocean. Which of the following best explains why?
Salinity is usually much higher in coastal regions,
Temperatures are cooler in coastal regions.
Ocean currents bring nutrient-rich water into coastal regions.
The shallow waters of coastal regions provide less oxygen

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.