Agreater amount of dna damage occurs when a living organism is exposed to a greater amount of a radioactive isotope. how might this affect the number of mutations acquired by the organism? a. more mutations will be acquired, leading to more phenotypic changes. b. the number of mutations will be the same because the same isotope was used. c. there will be no mutations because damaged dna is always repaired perfectly. d. fewer mutations will be acquired, leading to fewer phenotypic changes.

Option A, More mutations will be acquired, leading to more phenotypic changes

Explanation:

Radioactive material causes mutations in living organisms. Radioactivity is very harmful to living cells as it is ionizing in most of the cases which means it can remove an electron from an atom. When DNA in a human cell is exposed to radiation, its structure may get disrupted thereby causing loss of electrons and hence mutation. The mutated cell will not function like a normal cell and also the repair process of cell is slow. Therefore, once a cell is  mutated  it takes years to repair and there are high chances that it does not get repaired ever and is just carried to next generation.

These mutated cell will express certain distorted physical trait (phenotype). Thus, option A, is correct

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

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he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?