To act as a catalyst in chemical reactions
Answer:
Much change is due to random genetic drift rather than positive selection. Some are harmful and are likely to be eliminated by natural selection – by death of the embryo, for instance. ...
<span>This organelle is the nucleolus.
The nucleolus is made of proteins, DNA, and RNA. They form around specific regions of the chromosomes called nucleolar organizing regions. These regions of the chromosomes contain some the genes needed for ribosome production.</span>
A human with heterozygous genotype can have a dominant phenotype if one of the alleles complete mask the effects of the other.
- Heterozygous genotype involves two different alleles, unlike homzygous genotypes in which the alleles are the same.
- When the two alleles of an heterozygous genotype exert equal effects on one another, they are said to be codominant.
- When one of the alleles of an heterozygous genotype incompletely exert its effects on the other allele, it is said to be incomplete dominance.
- When one of the alleles complete dominates and masks the effects of the other allele, it is said to be dominant.
Hence, a dominant allele will always produce a dominant phenotype even if the genotype of the organism is heterozygous.
More on genotypes can be found here: brainly.com/question/14398652
Mainly by nitrogen-fixing bacteria in the soil and oceans
