The answer is true ...............good luck
Living organisms obtain many of their requirements by diffusion. They also get rid of many of waste materials in this way. For example, Plants need carbon dioxide for photosynthesis. This diffuses from the air into the leaves through the stomata. It does this because there is a lower concentration of carbon dioxide inside the leaf as the cells are using it up. Outside the leaf in the air, there is a higher concentration. Carbon dioxide molecules therefore diffuse into the leaf down this concentration gradient :)
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Answer:
- Interruption in the genetic flow between separated groups
- The emergence of new mutations in each of the groups, and their accumulation in time. Slow and gradual differentiation between populations.
- Genetic divergence by natural selection and reproductive isolation
- Prezigotic isolation mechanisms
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background that can give place to two or more new geographically isolated populations. These separations might be due to migration, extinction of geographically intermediate populations, or geological events. In this speciation, some barriers impede genetic interchange, or genetic flux, as the two new groups that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
The process of allopatric speciation involves different steps that affect organisms:
- The emergence of the barrier.
- Interruption in the genetic interchange
- The occurrence of new mutations and their accumulation in time in each population. Slow and gradual differentiation.
- Genetic divergence by natural selection and reproductive isolation makes it impossible for the two groups to mate even if the barrier disappears.
- Prezigotic isolation mechanisms will be favored by selection if occurs a secondary contact between the new species in formation.
Answer:
Cell membrane as a semi permeable membrane.
Explanation
A semi permeable membrane is the one that would only allow water,ions and certain molecules to pass through it by diffusion while restricting other large molecules from passing through.
Details in the attachment.