There are almost 500 naturally occurring variants of hemoglobin. most are the result of a single amino acid substitution in a globin polypeptide chain. some variants produce clinical illness, though not all variants have deleterious effects. identify the variant or variants that can be described by each of the three statements by placing the letter corresponding to the statement next to the variant. statement b may describe more than one variant, and a variant may be described by more than one statement. at least one variant will not match any description. a. the hb variant least likely to cause pathological symptoms. b. the variants most likely to show pi values different from that of hba on an isoelectric focusing gel. c. the variant most likely to show a decrease in bpg binding and an increase in overall affinity for oxygen.

Region b indicates the occipital lobe

answer: carbon 14 can only be used to determine the age of the organisms that were once living, and igneous rocks are non living.

explanation:

carbon 14 dating is used to determine the age of the sample by estimating the amount of carbon 14 present in the sample and then comparing it with a reference standard.carbon 14 is a isotope of carbon which is radioactive and unstable. carbon 14 is assimilated by all plants and animals throughout their life from carbon dioxide. however, one the organisms die they stop this assimilation and the carbon 14 content starts to decrease.by knowing how much of carbon 14 is left in an organism after his death, one can estimate the age of the organism. the materials whose age can be estimated by carbon 14 method are the organic compounds. however, some inorganic compounds such as aragonite   shell can also be dated.however, if we consider the igneous rocks it is a non living component which never accumulated carbon 14 in it and thus, we cannot use carbon 14 dating method to estimate its age.