Final answer:
Genomes encompass all of an organism's genes, and phenotypes are the traits expressed by these genes. A genotype is the genetic makeup of an individual, consisting of alleles inherited from each parent, which together with environmental interactions, determine an organism's phenotype.
Step-by-step explanation:
Genomes are the entire set of genes in organisms, while phenotypes are the characteristics and traits that are expressed by those genes.
The genetic material that an organism inherits from its parents is known as its genotype. This includes all the DNA sequences that contain the instructions for building and maintaining the organism. Genes are located on chromosomes, and the location of a gene on a chromosome is referred to as its locus. In diploid organisms, which include humans, two copies of the genome are present, with one set inherited from each parent. These matched pairs of chromosomes are called homologous chromosomes, and they carry the same genes, although possibly different versions of those genes, known as alleles.
Phenotype refers to the observable characteristics of an organism, such as hair color, eye color, and height. These observable traits result from the interaction of the genotype with the environment. For instance, Mendel's classic experiments with pea plants demonstrated that the phenotype of plant height was affected by whether the plants had one or two copies of the gene for tallness.
Alleles for different genes assort independently during meiosis, which is the process of cell division that results in the production of gametes (sperm and egg cells). These alleles make up the individual's genotype, which can be homozygous (two of the same alleles) or heterozygous (two different alleles). The expression of the genotype leads to the phenotype, where dominant alleles are typically expressed over recessive alleles in heterozygous combinations.