Genetic Experiments of Gregor Mendel: Sorting Valid Statements
What were the key findings from Gregor Mendel's experiments with pea plants?
a) All the members of Mendel's F1 generations exhibited the same phenotype.
b) Mendel's P generation included plants that were homozygous for different alleles of the same trait.
c) Some members of Mendel's F2 generation are heterozygous.
d) Which of Mendel's generations produced offspring of only one genotype?
Answer:
The statements a) and b) are valid as Mendel's F1 generation showed the same phenotype due to all being heterozygous, and the P generation consisted of homozygous plants. Statement c) is also valid since variation in the F2 generation implies the presence of heterozygous plants. The answer to d) is that the F1 generation all had the same genotype when considering a single trait.
Explanation:
Gregor Mendel's ground-breaking work with pea plants laid the foundation for our understanding of genetics. He meticulously cross-bred pea plants to observe how traits were inherited from one generation to the next, leading to the discovery of dominant and recessive alleles.
Let's sort the provided statements:
a) All the members of Mendel's F1 generations exhibited the same phenotype. This statement is valid. The F1 generation resulted from cross-fertilizing purebred P generation plants with contrasting traits, leading to offspring that were all heterozygous, displaying the dominant trait.
b) Mendel's P generation included plants that were homozygous for different alleles of the same trait. This statement is valid. Mendel started his experiments with P generation plants that were purebred, meaning they were homozygous for a specific trait.
c) Some members of Mendel's F2 generation are heterozygous. This statement is valid. The F2 generation showed variation in traits, which implies that some of the plants had heterozygous genotypes.
d) Which of Mendel's generations produced offspring of only one genotype? This question is slightly ambiguous but implicitly refers to the F1 generation. All F1 offspring had the same genotype (Yy) and phenotype (yellow round seeds), but only when considering a single trait. For a full understanding, it's essential to look at multiple traits and recognize that the P generation was also of a single genotype, but each parental line had different genotypes from each other (YY and yy for a given trait).