Genetic Cross in Guinea Pigs: Understanding Mendel's Laws
Question:
In a genetic cross of Gg with Gg guinea pigs, none of the four offspring were gg. This...
a. disproves Mendel's law of independent assortment.
b. neither supports nor disproves Mendel's law of independent assortment.
c. supports Mendel's law of independent assortment.
d. supports Mendel's law of segregation.
Final answer:
Answer:
The absence of gg offspring in a genetic cross of two Gg guinea pigs neither supports nor disproves Mendel's law of independent assortment.
Explanation:
The question regarding a genetic cross in guinea pigs, in which none of the four offspring are gg, pertains to Mendel's laws of inheritance. When a Gg guinea pig is mated with another Gg guinea pig, the expected genotypic ratio is 1GG : 2Gg : 1gg, according to Mendel's law of segregation. This law states that alleles segregate into gametes, allowing offspring to have an equal likelihood of inheriting either allele from each parent.In the scenario where none of the offspring are gg, the result neither supports nor disproves Mendel's law of independent assortment, because the law of independent assortment applies to genes on different chromosomes or far apart on the same chromosome. The four possible gametes when crossing Gg individuals are still G and g from each parent, forming combinations of GG, Gg, and gg. The absence of gg offspring in this small sample size could be due to chance rather than any inconsistency with Mendelian laws.
Therefore, the correct answer is: b. neither supports nor disproves Mendel's law of independent assortment.