Question: Justify the hypothesis of early microorganisms were chemolithotroph and why phototrophic organisms that came after had pigments that absorbed maximally at UV and IR radiation Question: Although physiologically distinct, chemolithotrophs and chemoorganotrophs share a number of features with respect to the production of ATP. Discuss these common features along with reasons […]

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 […]