Answer:
c. The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism's DNA
Explanation:
Mutations are changes in DNA sequence that can create genetic variation within the population. Mutations are important for evolution because of their ability to form a new genetic variant (allele) that can be spread to the offspring. If a new variant of a trait formed by a mutation is advantageous and helps the organism to survive and reproduce, it is going to be favourable by natural selection. That variation will more likely be passed to the next generation and remain over time.
While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion.
Answer:
Eutrophication
Explanation:
Algal bloom:
Algal bloom is the overgrowth of algae in a marine or freshwater environment resulting in pungent odors and discoloration of water. Algal blooms arise in nutrient rich water due to a process called eutrophication.
Eutrophication is the presence of excess nutrients in water that promote the growth of algae and aquatic plants. This excessive growth results in the depletion of oxygen.
Eutrophication causes the build-up of inorganic chemicals such as ammonia, hydrogen sulphide and nitrites to a level that becomes toxic for fish and organisms. This coupled with depletion of oxygen kills fish resulting in the addition of more nutrients to the water.