A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a brain attack.. If blood flow is cut off for longer than a few seconds, the brain cannot get nutrients and oxygen. Brain cells can die, causing lasting damage.
A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes. The cell or organism in question is called a homozygote. True breeding organisms are always homozygous for the traits that are to be held constant.
Homozygous dominant is a genotype that consists of two dominant alleles for a gene. Although a homozygous dominant cat might have the same phenotype, or appearance, as a heterozygous one, the difference is that the homozygous dominant individual will 'breed true'.xample of Homozygous Dominant. In cats, the agouti allele is dominant. It causes each hair in the cat's coat to have sections that are black and sections that are another color, such as gray. Tabby cats have the agouti allele, giving their fur a multicolored appearance.