The autotrophic protists can photosynthesize, while the heterotrophic protists can’t.
The liver breaks down many substances in the blood, including toxins. The liver also excretes bilirubin — a waste product of hemoglobin catabolism — in bile. ... The lungs are responsible for the excretion of gaseous wastes, primarily carbon dioxide from cellular respiration in cells throughout the body.
Mutualism, both of the animals benefit from the relationship.
Answer:
C. Characters with little genetic variation will constrain the rate of natural selection
Explanation:
Natural selection can have an effect only as long as there are variations on characters on which it can select upon. Genetic variation is independent of the environment or the needs that a species may have to become better adapted to its changing environment. In other words, genetic mutations are the raw material on which natural selection can work. If there is a low rate for mutations to occur, then natural selection will proceed at a slow pace. The opposite is also true. Since mutation rate may be more frequent at some locations in a gene than at others, it can be predicted that the characters coded in that gene location will be more likely to be affected by natural selection and therefore what phenotype may be molded by natural selection.
Plant cells have what is perhaps the most complex outer coverings. Plant cell walls are made largely of cellulose which forms strong, highly rigid, almost indigestible coverings that protect the cell and gives it shape.