No, the sickle-cell anemia allele won't be eliminated by natural selection.
Sickle-cell anemia trait is controlled by a single gene and the allele (S) for sickle-cell anemia is a harmful autosomal recessive.
It is caused by a mutation in the normal allele (A) for hemoglobin (a protein on red blood cells).
Heterozygotes (AS) with the sickle-cell allele are resistant to malaria, a deadly tropical disease. It is common in many African populations.
In these areas, (S) carriers have been naturally selected, because their red blood cells, containing some abnormal hemoglobin, tend to be in sickle shape when they are infected by the malarial parasite.
Therefore, they are more likely to survive and reproduce. This keeps the S allele in the gene pool.
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The role of the Golgi body or Golgi apparatus is to package the proteins in vesicles and target it to their respective place of function. Example, the receptor proteins that are synthesised in the Endoplasmic Reticulum will be sent to the Golgi body for its packaging into the vesicles that bind and fuse with the cell membrane. The targeting is done by the special set of markers present on the secreted vesicle. All the eukaryotic cells have a Golgi apparatus. When chemical treatment is done to stop its functioning, the cell stops functioning and eventually dies due to the hampered targeting of proteins to the various organelle. On the other hand, prokaryotic cells lack Golgi body as the cell size is small enough to allow for the synthesised protein to move by diffusion to its target. Hence no effect will be seen when prokaryotic cells are treated with that chemical.
The species was a keystone species.
Keystone species are the species that ''hold the ecosystem together''.
They have an important role in the trophic networks (food chains) and often they can even afflict changes in the abiotic part of the ecosystem (change the composition of soil, purify the water, lower the effect of the wind etc)
Therefore, when a keystone species is removed it affects greatly the whole ecosystem.
Answer:
respiration, waste production, food intake, cells, breathing
They often respond to Quorum sensing which is determined by the cell density. Bacteria cells secrete molecules that can be detected by other bacteria, Quorum sensing allows bacteria to sense the concentration of these signalling molecules to monitor the local density of cells. It used by bacteria to coordinate certain behaviors , such as the production of biofilms.
