AP BIOLOGY

Detailed explanation-1: -In sexually reproducing organisms, each parent contributes half of the genes acquired (at random) by the offspring. Individuals have two of each chromosome and hence two alleles of each gene, one acquired from each parent. These versions may be identical or may differ from each other.

Detailed explanation-2: -An international research effort called the Human Genome Project, which worked to determine the sequence of the human genome and identify the genes that it contains, estimated that humans have between 20, 000 and 25, 000 genes. Every person has two copies of each gene, one inherited from each parent.

Detailed explanation-3: -Each of your parents has two copies of each of their genes, and each parent passes along just one copy to make up the genes you have. Genes that are passed on to you determine many of your traits, such as your hair color and skin color.

Detailed explanation-4: -An individual inherits two alleles, one from each parent, for any given genomic location where such variation exists. If the two alleles are the same, the individual is homozygous for that allele. If the alleles are different, the individual is heterozygous.

Detailed explanation-5: -If parents pass on both copies of a gene pair, then offspring would end up with four genes for each trait. Mendel deduced that sex cells-sperm and eggs-contain only one parental gene of each pair. The half-sets of genes contributed by sperm and egg restore a whole set of genes in the offspring.