Answer:
Species separated by a physical barrier for a long time, suffer allopatric speciation, so they can not interbreed anymore.
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background giving 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 flow, as the two new populations that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
Vicariance is the geographical separation of an original population into two or more new groups. Discontinuities in the physical environment like rivers, mountains, water, etc., are physical barriers that impede genetic flow between the separated groups.
The process of allopatric speciation involves different steps:
- 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 favored by selection once occurs a secondary contact between the new species in formation.
It’s A the immune system & lymphatic Hope this helps!
Explanation:
Evolution involves changing the hereditary characteristics of a population through generations. These traits are the expression of genes that are passed on to offspring during reproduction.
Answer:
Explanation:
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.
ORR
Struggle for existence, variation and inheritance. These are said to be the necessary and sufficient conditions for natural selection to occur.
Answer:
b. A transferase deficiency will result in an accumulation of the toxic metabolite galactosse 1-phosphate.
c. A galactokinase deficiency will cause an accumulation of galactose.
Explanation:
Transferase is an enzyme which is responsible for the breakdown of galactose which is a known milk sugar. Its deficiency causes the formation of toxic materials such as galactose-1-phosphate which comes from galactose, and galactitol. Galactokinase is also an enzyme which helps in the conversion of galactose into galactose 1-phosphate with the expenditure of ATP molecule, so its deficiency causes the deposition of galactose.
