Answer:
a
Explanation:
b. speciation
c. convergent selection
d. stabilizing selection
Speciation occurs when a population suffers divergence. Genetic flow is interrupted between the new groups that keep reproducing and going through mutations. Reproductive isolation emerges. Option B. Speciation.
Occurs when the original population is divided into two or more groups and each group is exposed to different environments.
Each group reproduces for many generations, going through many changes or mutations.
These changes will depend on each group's environment and its ecological pressures.
Pressures act on individuals and make them adapt to the new environmental conditions.
Generation after generation, the genotype of individuals will increase the fitness to survive and reproduce.
The fixation of mutations will increase the difference among both groups, up to the diverging point into two new species.
There are different types of speciation. One of them is Allopatric speciation.
Allopatric speciation refers to the geographical separation of a continuous genetic population, originating two or more new geographicallyisolated groups.
During these events of speciation, emerging new barriers impede genetic flow between groups. The two new populations that are separated can not get together and mate anymore.
These barriers might be geographical or ecological.
After the emergence of the barrier, the two populations evolved separately in different new species.
Two different species that evolved in allopatry might meet again in secondary contact if the barrier that separated them, disappears. However, they will not be able to mate and reproduce due to prezygotic and postzygotic reproductiveisolation.
The exposed example is a case of speciation, in which the chimpanzees' habitat was fragmented and a town was built.
The town acts as the barrier between the two diverged groups, impeding them to meet.
Genetic flow is interrupted and each group keeps reproducing separately, and mutating, leading to genetic changes and reproductive isolation.
After a long period of time, the chimpanzees came back into contact but were incapable of breeding.
This process is speciation. Option B.
You can learn more about speciation at
Decomposing
Photosynthesis
Cellular respiration
The factor which makes the permeability of the plasma membrane a main reason for the cells existence is that this condition makes the cell a to take in important required substances and throw out waste. Thus, the life of the cell is based the fact that the plasma membrane is selectively permeable.
Further Explanation:
Eukaryotic cells are the cells which have membrane-bound organelles, membrane-bound nucleus, and several chromosomes. They have a true nucleus and have some similarity with prokaryotic cells like plasma membrane, cytoplasm, and ribosomes.
Plasma membrane is selectively permeable as they allow only certain molecule to pass through them. This permeability is dependent on many factors one of them being the need of the molecule by the cell. The membrane of the cell is made up of following components;
1. Phospholipid bilayer
2. Transmembrane proteins
3. Interior protein network
4. Cell surface markers
Out of these components the one responsible for maintaining the movement of the chemicals or molecules across the membrane is the phospholipid bilayer and the transmembrane proteins. The major component which acts as an permeability barrier is the phospholipid bilayer.
Learn more:
1. Learn more about which structure is unique to eukaryotic cells brainly.com/question/4493579
2. Learn more about the purpose of transfer RNA brainly.com/question/236807
3. Learn more about translation brainly.com/question/273550
Answer Details:
Grade: High School
Subject: Biology
Chapter: Cell biology
Keywords:
Eukaryotic cell, DNA, cell membrane, ribosomes, nucleus, plasma membrane, cytoplasm, chromosomes, endoplasmic reticulum, nucleolus, phospholipid bilayer, transmembrane proteins.