Question

6
directions: select each correct answer. more than one answer may be correct.
mutations occur when segments of dna are accidentally rearranged through the deletion, insertion, or substitution of one or more
nucleotides the diagram below shows how a nucleotide sequence can be changed by these mutations
atc atc ttt gtt
deletion
atc att ttg tt
the second c was deleted
insertion
atc atc tta tgt t
an extra a was inserted
substitution
atc gca ttt gtt
atc was substituted with gca
if one or more of these mutations occurs in the genes of reproductive cells, how might the traits of offspring be affected?
they may be harmed
they may not be affected at all
they may receive a benefit

Explanation:

基因突变（mutation）是指基因组DNA分子发生的突然的、可遗传的变异现象。基因突变可能是中性的（对生物没有影响）、有害的（导致疾病等不良后果）或有益的（为生物进化提供原材料）。当生殖细胞（reproductive cells）的基因发生突变时，这些突变可能会传递给后代（offspring）。如果突变发生在关键基因区域，可能会对后代的性状（traits）产生有害影响（如导致遗传疾病）；如果突变发生在非关键区域或突变后的基因功能仍能维持正常，后代可能不受影响；在某些情况下，突变也可能使后代获得有益的性状（如对某种环境的适应性增强）。

Answer:

• They may be harmed
• They may not be affected at all
• They may receive a benefit