Define the terms penetrance and expressivity and explain how they affect the expression of single gene traitsWhat will be an ideal response?
ANSWER: The terms penetrance and expressivity define two different aspects of phenotypic variation.
Penetrance is the probability that a disease phenotype will be present when the disease genotype is present. For example, if all individuals carrying the allele for a dominant disorder
have the mutant phenotype, the gene has 100% penetrance. If only 25% of those who carry
the mutant allele show the mutant phenotype, penetrance is 25%. If the phenotype of a trait is
present in less than 100% of those with the related genotype, the trait is said to show
incomplete penetrance. Expressivity refers to the range of phenotypes resulting from a given
genotype. For example, a genetic disorder called camptodactyly causes an unmovable, bent
little finger. All dominant allele homozygotes should have a bent little finger on both hands.
However, some of those affected have only one bent finger or normal fingers on both hands,
but must carry the mutant allele because it can be passed on to children, each of whom may
have some level of expression.
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Cyanobacteria obtain energy through ________
Fill in the blank(s) with correct word