Answer:
B. To make sure that the two new cells have slightly different genetic codes.
Explanation:
<h2><u>Full Question:</u></h2>
In the alveolus pictured above, a disease or injury to which structures would reduce the ability of oxygen to diffuse from the alveolar space to the capillary?
A. A and B
B. B and C
C. B and D
D. A and D
<h2><u>Answer:</u></h2>
The correct answer is option D.
<h3><u>Explanation:</u></h3>
Alveoli is defined as the unicellular thickened sac like structure of lungs which helps in exchange of gases in lungs. The exchange membrane of lungs comprise of three structures -
A. The epithelium cells of Alveoli,
B. The basement membrane of alveolar epithelium,
C. The endothelial layer of blood capillary.
The red blood cells described here won't cause any problems to the diffusion of gases from alveolar cavity to blood. The structures mentioned here as the type 2 cells of Alveoli which secrete lecithin, a surfactant which releases the surface tension of Alveoli. This compound prevents the Alveoli from collapsing and helps in diffusion of gases. The other structure mentioned here as D are the alveolar epithelium which is the unicellular thickened membrane of Alveoli, helping in gaseous exchange.
The theory would be endosymbiont theory. It was developed on the idea that some eukaryotic organelles come from prokaryotic organisms. It is also known as symbiogenesis. This theory says that these organelles were first from prokaryotic cells that is living inside a host cell.
Answer:
a. one allele from each parent
Explanation:
According to Mendel, gametes are always pure and contain one allele for each gene. Let's assume that the genotype of the tall plant is "TT" and the genotype of the short plant is "tt". The tall plant would produce all the gametes with one copy of the "T" allele while all the gametes from the short plant would carry only the "t" allele.
The random fusion of gametes from tall and short parent plant produces all the F1 progeny with genotype "Tt". Here, each F1 plant obtained one "T" allele from the tall parent plant and one "t" allele from the short parent plant.
Answer:
Bird irruption and climatic phenomena subsequently
Explanation:
The Hawaiian islands are extremely diverse in both flora and fauna species. Today, similarly to the Galapagos Islands, there are thousands of species of Hawaiian finches, some of them eat seeds, others fruit, while other nectar, etc. Also, their beaks and colors are incredibly variable.
After years of research, scientists determined that it was one finch progenitor that arrived from Asia to the Hawaiian Islands around 6 million years ago, which gave rise to this process of speciation. This situation, as suggested by the researchers, occured due to a phenomenon known as 'irruption', characterized by the movement of hundreds to thousands of birds from one region to another located very far.
This finch is suggested to have gotten carried away in a storm, which eventually brought it to the Hawaiian Islands.
