Suppose you have high sensitivity to the taste of PTC. If...

Key Concepts

Punnett Square Analysis

This analytical tool is used to predict the probability of offspring inheriting particular genotypes and phenotypes from their parents. By considering the possible allele contributions from a parent with low sensitivity and a parent with high sensitivity, one can determine which alleles must have been contributed by each parent.

Genotype and Phenotype

The genotype is the set of genes an individual carries, while the phenotype is the observable expression of those genes. This concept explains how the combination of alleles from each parent results in the sensory trait being exhibited, such as the ability or inability to taste a chemical.

Dominant and Recessive Alleles

In genetics, alleles are different versions of a gene, where dominant alleles mask the effect of recessive ones in heterozygous individuals. A trait that shows high sensitivity can be due to the presence of a dominant allele, while low sensitivity would be due to a recessive allele, defining how a trait is expressed in an individual.

Genetic Inheritance

This concept involves the transmission of traits from parents to offspring through genes. It explains how observable traits, or phenotypes, such as taste sensitivity to a chemical, are influenced by the genetic makeup inherited from both the mother and the father.

Transcript

00:01 So for this question, it's very important to look at the information you have and to see what you can deduce using punnet squares.

00:07 So we're looking at the ptc gene in this question, and this gene establishes whether or not you can taste a specific herb.

00:14 And if you have at least one dominant allele represented by the capital t, that means that you can taste this herb and that it is bitter.

00:23 And if you have two recessive alleles represented by the lowercase tea, that means that you can't taste.

00:30 This herb so you're non -tasting and this question also gives you more information it tells you that you are able to taste the herb and you're highly sensitive to it and that means there are two options you're either homozygous dominant or heterozygous and you're also told that your mother is not sensitive to this she has low sensitivity which means she can't taste the herb and that means there's only one option.

01:01 She's homozygous recessive.

01:03 And this actually helps you narrow down what your genotype is, because you can only get one allele from your father and one allele from your mother.

01:11 And your mother has, can only give you a recessive allele.

01:16 And since you can taste the herb, that means your other allele that you got from your father must be a dominant allele.

01:23 So that means your heterozygous.

01:25 But what does this tell us about your father's genotype? so we know that there are three options.

01:33 Your father could either be homozygous dominant, heterozygous, or homozygous recessive...

Please give Ace some feedback