Q1. A typical prokaryotic cell has about 3,000 genes in its DNA, even as a human cell has about 25,000 genes. About 1,000 of these genes are present in both types of cells. Based on the understanding of evolution, describe how such different organisms might have this same subset of […]

The mutated form of hemoglobin (hemoglobin S, or HbS) in sickle-cell anemiaresults from the replacement of a glutamate residue by a valine residue at position 6 in the chain of the protein. (Normal hemoglobin is HbA.)   HbS has normal shape under normal conditions, but under conditions of low [O2] the hemoglobin forms […]

Question: Gene frequencies for the ABO alleles vary geographically. For example the I^A allele makes up nearly 50% of the genes for blood type among Australian Aborigines, about 25% in Central Asian populations, and 0% in peoples native to South America. No blood type has sufficient selective advantage over another to […]

Answer the following questions in terms of physical and/or chemical factors that might explain, or partially explain, various divisions in the Figure 1 classification. 1. The division between the epipelagic and mesopelagic zones.2. The division between the mesopelagic and bathypelagic zones. This boundary is about 1000 meters deep, and it […]