Question

this passage describes the cystic fibrosis trait in humans:
cystic fibrosis is a condition that affects mucus. mucus is a jelly - like substance that certain cells produce to protect the body from infection. humans with cystic fibrosis produce mucus that is thicker and stickier than usual. this sticky mucus builds up in the lungs and interferes with breathing.
in a group of humans, some individuals have cystic fibrosis and others do not. in this group, the gene for the cystic fibrosis trait has two alleles. the allele f is for not having cystic fibrosis, and the allele f is for having cystic fibrosis.
vicky, a human from this group, does not have cystic fibrosis. vicky has two alleles for not having cystic fibrosis.
based on this information, click the blue words to correct any errors in the text.
vicky does not have cystic fibrosis. this is vickys phenotype for the cystic fibrosis trait.
vicky is heterozygous for the cystic fibrosis gene.
vickys phenotype for the cystic fibrosis gene is ff.

Explanation:

1. For the first sentence: "Vicky does not have cystic fibrosis. This is Vicky's phenotype for the cystic fibrosis trait." - "phenotype" is correct here as phenotype refers to the observable characteristic (whether she has the disease or not), and "does not have" is an accurate description of her phenotype, so no error here.
2. For the second sentence: "Vicky is heterozygous for the cystic fibrosis gene." - The passage states Vicky has two alleles for not having cystic fibrosis (so her genotype is FF). Heterozygous means having two different alleles (e.g., Ff), while homozygous means having two identical alleles (FF or ff). So "heterozygous" is incorrect. It should be "homozygous".
3. For the third sentence: "Vicky's phenotype for the cystic fibrosis gene is Ff." - "Phenotype" is the observable trait (like having or not having the disease), while "genotype" is the genetic makeup (the alleles, like FF, Ff, or ff). Since Vicky has two alleles for not having cystic fibrosis, her genotype is FF, and her phenotype is "does not have cystic fibrosis". So "phenotype" here is incorrect, it should be "genotype", and "Ff" is also incorrect, it should be "FF".

Answer:

• Second sentence correction: Change "heterozygous" to "homozygous".
• Third sentence correction: Change "phenotype" to "genotype" and change "Ff" to "FF".