Answer:
b. it involves a physical exchange of segments from homologous chramosomes.
Explanation:
Crossing is a phenomenon involving homologous chromatids. It consists of the breaking of these chromatids at certain points, followed by an exchange of corresponding pieces between them.
Exchanges cause new gene sequences to appear along the chromosomes. Thus, if on a chromosome there are several genes combined in a certain sequence, after the occurrence of crossing the combination may no longer be the same. So when thinking about crossing, it is common to analyze what would happen, for example, about the combination of the allele genes "A" and "a" and "B" and "b" in the pair of homologues.
Answer:
The simplest definition of an ecosystem is that it is a community or group of living organisms that live in and interact with each other in a specific environment.
Seas, rivers
Explanation:
this is the correct answer you want
To a plant, leaves are food producing organs. Leaves "absorb" some of the energy in the sunlight that strikes their surfaces and also take in carbon dioxide from the surrounding air in order to run the metabolic process of photosynthesis. The green color of leaves, in fact, is caused by an abundance of the pigment "chlorophyl" which is the specific chemical agent that acts to capture the sunlight energy needed for photosynthesis. The products of photosynthesis are sugars and polysaccharides. An important "waste product" of photosynthesis is oxygen. To an animal, a leaf may be a food source or a place to live on or under.
Answer:
A.) for souvenirs
Explanation:
Tourists are interested in mining corals mainly to get souvenirs, since corals are known to be pretty and would be a "good" souvenir because of that.
Tourists would not be interested in mining corals to build roads, get protection, or get bone grafts because tourists are just interested in visiting a place and getting souvenirs from it.