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.
Answer:
1. B Prokaryotes lack a nucleus and membrane-bound organelles
2. C glucose
It is an hydrophilic substance....<span>Substances that have charge or polarity are </span>hydrophilic<span>, and are likely to dissolve because they have either full or partial charge areas to form hydrogen bonds with water molecules.</span>
Fat (lipid) molecules are made up mostly of long chains of carbon atoms.
For a fat molecule to be considered saturated, the carbon chain must have only single bonds between them.
Schematically, they look like -C-C-C-C- ...
If the carbon chain contains one or more double bonds, such as -C=C-C-C, then the given lipid molecule is unsaturated.
If a lipid molecule (fatty acid) contains exactly one double bond in its chain, and the rest are single bonds, it is then called monosaturated. It is a more healthy food source than saturated fats.
Saturated fat are generally solid at room temperatures. Examples include lard, butter, mostly from animal sources. However, coconut oil (solid at room temperatures as well) is a saturated fat.
