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.
Learn more about Sickle-cell anemia on
brainly.com/question/14505007
#SPJ4
Answer:
a. different alleles of the seed shape gene.
Explanation:
Mendel crossed different varieties of pea plants and he observed how phenotypic traits passed to the progeny. From these experiments, Mendel formulated the 'First Law of Segregation', where he observed that traits may exist in pairs that segregate (separate) at meiosis. During meiosis, i.e., gamete formation, these two factors separate from each other, thereby each gamete has the same probability of receiving either factor. Nowadays, we know that these two factors represent two different gene variants or 'alleles' for a given gene <em>locus</em>. Alleles can be classified into dominant or recessive as in the example above described, where the R factor (round) dominates on the r factor (wrinkled) to determine the seed shape.
C, because it protects the cell from the outside environment
Answer: The flow of individuals in and out of a population introduces new alleles and increases genetic variation within that population. Mutations are changes to an organism’s DNA that create diversity within a population by introducing new alleles.
Explanation:
