Answer:
The correct option is <em>A. convergent evolution</em>
Explanation:
The phenomenon of evolution explains how different species might have common ancestors. This phenomenon explains that genetic variations might have led to the birth of different species from a common ancestor.
Convergent evolution can be described as a type of evolution in which similar features or traits can be observed in organisms although they may not have any genetic sequence in common. For example, sharks and dolphins look similar but they have huge differences in their genomes.
Hyothalamus is the thermostat of the human body
Answer:
Explanation:
The sickle cell allele is recessive. Hence, in order for any child of the couple to have sickle cell anemia, such a child will have to inherit an affected allele each from the two parents. This means that both the father and the mother must have affected alleles in their genotypes. In other words, two sickle cell alleles are required for the abnormality to manifest.
Let us assume that the sickle cell allele is represented by S and the normal allele is represented by A.
Now, it is established that the mother has sickle cell anemia, her genotype would be SS. The father does not have sickle cell, his genotype can either be AA or AS.
Assuming the genotype of the father is AA:
SS x AA
AS AS AS AS
<em>All the children would be normal in this case.</em>
Assuming that the genotype of the father is AS
SS x AS
AS SS AS SS
<em>50% of the children would have sickle cell while the remaining 50% would be normal.</em>
<u>Therefore, in order to produce children with sickle cell, the father has to be AS, otherwise, he has to be AA.</u>
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In populations of all living things, there is a variation of different traits. This is important for the process of evolution and natural selection because if the individuals in the population vary in size, shape, color or any other morphological or physiological trait, the individuals can be more or less successful because of them and therefore natural selection can filter the variations that are the fittest for that environment.