Explain how the alleles were passed from parents to offspring
The Correct Answer and Explanation is :
Alleles are different versions of a gene that are passed from parents to offspring during reproduction. The process by which alleles are inherited follows the principles of Mendelian genetics, named after Gregor Mendel, who studied inheritance patterns in pea plants. Here’s how the alleles are passed from parents to offspring:
Each individual has two copies of every gene, one inherited from each parent. These two copies are called alleles. The alleles can be dominant or recessive. Dominant alleles are expressed even when only one copy is present (represented by a capital letter), while recessive alleles are only expressed when both copies are recessive (represented by lowercase letters).
When gametes (sperm and egg cells) are formed through a process called meiosis, each parent contributes only one allele per gene to the offspring. This occurs because meiosis reduces the chromosome number by half, ensuring that when the sperm and egg combine during fertilization, the resulting offspring has two alleles per gene—one from each parent.
The combination of alleles from the two parents determines the genotype of the offspring. For example, if one parent passes a dominant allele (A) and the other parent passes a recessive allele (a), the offspring will have the genotype Aa, and the dominant allele (A) will determine the phenotype, or physical expression, of the trait.
In Mendelian inheritance, the way alleles are passed on can be predicted using a Punnett square, which shows the possible genetic outcomes based on the alleles contributed by each parent. If both parents are heterozygous (Aa), there’s a 25% chance their offspring will inherit two recessive alleles (aa), a 50% chance of inheriting one dominant and one recessive allele (Aa), and a 25% chance of inheriting two dominant alleles (AA).
In summary, alleles are inherited through the fusion of gametes, with each parent contributing one allele, and the combination of these alleles determines the offspring’s traits.