Figure 1. model of water movement through the xylem, with magnified models of water movement in the stem and leaf. which statement describes how water is pulled up through the xylem to the leaves of the plant?

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Awire-hair terrier and a smooth-hair terrier are mated. the offspring produced are 6 wire-hair puppies and 2 smooth-hair puppies. a. what pattern of inheritance best describes this situation? b. what is the genotype(s) of the wire-haired puppies? of the smooth-haired puppies? c. what would be the expected genotype and phenotype ratios of a mating between 2 wire-haired terriers that are heterozygous?

The negative impacts of nonnative species generally outweigh the positive impacts