Answer:
Option A, Ohio River and the Missouri River
Explanation:
The historical evidences clearly indicate that Ohio River did not exist before the last ice advances. Before Ohio and Missouri river, the major glacier drainage of the east-west direction happens in Teays River. When ice of the glaciers blocked the Teaya river valley, then the Ohio was formed.
Like Ohio, Missouri river did also not exist before Pleistocene and during that time the largest drainage in North America take place in the Hudson's Bay
Hence, option A is correct
Answer:
phytoplankton
Explanation:
Phytoplankton can be defined as a set of photosynthesizing microorganisms that live floating on the water surface. It is composed of microscopic algae and cyanobacteria, which can be unicellular, colonial or filamentous. These microorganisms are defined as the primary producers of an ocean grazing food network.
Because phytoplankton live in aquatic environments - both in limic (eg lakes) and marine environments - they have a number of adaptations that guarantee their survival in the water column. Some of these microorganisms, for example, have flagella that aid locomotion; others, in turn, have gas vacuoles that aid in flotation, while some of them have mucilage, which surrounds the cells and ensures protection, flotation and locomotion.
Answer:
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Explanation:
Evolution, in genetic terms, involves a change in the frequency of alleles in a population over time. What are the sources of genetic variation? Three sources of genetic variation are mutation, genetic recombination during sexual reproduction and lateral gene transfer.
A virus is not a living thing. It is made of genetic material inside a protein coat. A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea. It is an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.
