Question

Which would least likely result from a chromosomal change?



a.death of the cell or organism

b.no effect on the cell or organism

c.enhanced ability of the organism to reproduce

d.change to the phenotype of the organism

Answer 1

Chromosomal changes usually lead to some kind of disease (like Down Syndrome) or abnormal reproduction, like polyploid fruits. Chromosomes make up DNA so it will definitely change something in the organism. Would you say polyploidy is an "enhancement?" For humans, yes, because polyploid fruits tend to be bigger so we manipulate plant reproduction to get the big strawberries found in supermarkets. I would say D because no matter what the ultimate effect is, the organism is still different than what it would have been without the mutation.

Answer 2

I disagree. @JessicaHW Many plants accumulate massive amounts of chromosome copies and have no phenotypic effects. In fact, we have only a good idea at why this occurs. I think the answer hinges on who the question maker defined "chromosomal change". Are we talking SNPs, gene deletion/duplication, mass alterations in a chromosome such as the rare cases in which a large chunk of a chromosome breaks out, reverses, and is reinserted, or something like whole chromosome/genome duplication or deletion. Yes, whole genomes can be lost when talking about mitochondria or chloroplasts.