An example of a genotype is:
a. A tall pea plant.
b. R and r.
c. TtHH.
d. Hemophiliac.
The correct answer and explanation is:
The correct answer is c. TtHH.
A genotype refers to the genetic makeup of an organism, specifically the alleles that an individual inherits from its parents. It is represented by the combination of letters that show the version of a gene that is present, whether dominant or recessive. In this example, TtHH is a genotype because it shows the alleles for two different genes.
- Tt refers to the alleles for one gene, where “T” could represent a dominant allele for a trait (like tallness in pea plants), and “t” represents the recessive allele (which would result in a short plant if inherited in a homozygous state).
- HH refers to the alleles for another gene, in this case, a dominant homozygous pair, which might represent a trait like normal clotting in hemophilia.
To clarify the other choices:
- a. A tall pea plant describes a phenotype, which is the observable characteristic or trait of an organism, not its genotype.
- b. R and r describes alleles but is incomplete. The combination of these alleles (such as Rr or RR) would be considered a genotype.
- d. Hemophiliac refers to a condition or phenotype and not the genotype. It describes an individual who expresses a certain genetic condition, but does not give information about the actual genetic composition (such as XhXh or XhY).
In summary, a genotype is an organism’s genetic code, represented by alleles for specific traits. The genotype TtHH illustrates this concept, showing how the combination of different alleles can influence the traits expressed by an individual.