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:
Because water exhibits cohesive behavior.
Explanation:
Cohesive behavior can be explained as a behavior where molecules are attracted to each other.
And this means that, water molecules are attracted to each other because of their cohesive behavior. This makes them to be attracted to other substances, such as the walls of the xylem of plants.
In this case, it is believed that the water molecules behave this way because they are polar, that is, there is an electronegativity difference between the bonded atoms. And this enables it to move from the roots to the leaves of the plants.
The correct answer should be The ability to reproduce only within a species.
The only independent variable in this experiment is the amount of nitrogen Sarah uses. All of the other variables are dependent on other factor and processes, but Sarah controls the amount of nitrogen that she uses for each plant.
Every plant organ is adapted to its function. For example, leaves that are big and flat absorb plenty of sunlight for photosynthesis. Long roots keep a tree stable and take water from deep in the soil. Some plants have unusual adaptations.
