Answer:
C
Explanation:
It moves across the cell membrane via simple diffusion, a process that requires no energy input and is driven by the difference in concentration levels on each side of the cell membrane.
Sickle cell anemia is caused by an abnormal hemoglobin in red blood cells. hemoglobin is the red pigment found in red blood cells for carrying oxygen.The abnormality arises from a genetic mutation in the DNA gene that codes for the beta chain of the protein called globin of which hemoglobin is made of.In the beta chain, the sixth amino acid called glutamine is replaced by another one called valine.<span>This one change in the amino acids cause the hemoglobin protein to behave abnormally, causing red blood cells to lose their normal spherical shape and become bent like a sickle, hence the name "sickle cell" anemia</span>
The two types of succession are primary and secondary. <span> Primary succession is the series of changes that occur on an entirely new habitat which has never been colonized before, while secondary occurs on places that have already been colonized before.</span>
<h2>Mesophyll cells</h2>
Explanation:
The most distinctive characteristic of leaf mesophyll cells is that they are filled with many chloroplasts
Mesophyll cells constitute the main body of a leaf, occurring between upper and lower epidermis
Typically, the leaves of temperate-zone plants have two layers of mesophyll cells, the palisade mesophyll on the upper side and the spongy mesophyll on the lower side
The palisade mesophyll is a layer of densely packed, columnar cells which contain many chloroplasts, this layer is responsible for most of the photosynthesis of leaves
The spongy mesophyll is composed of large, often odd-shaped, photosynthetic cells separated from one another by large, intercellular spaces, these intercellular spaces apparently facilitate the exchange of photosynthetic gases
Answer:
According to the diagram, cell growth and preparation occur in steps 2 and 4, corresponding to phases G₁ and G₂ of cell cycle.
Explanation:
G₁ phase consists of the beginning of the cell cycle, following the process of previous division, and occurs in a cell that prepares for a next division. In this phase growth depends on the proliferation of mRNA to increase protein synthesis.
G₂ phase —third phase of the cycle— is the continuation of the process of cell growth induced by protein synthesis. Changes occur at the level of cellular components, as preparation of the cell prior to division.
