the passing of traits from parent to offspring
heredity
any alteration in the sequence of DNA
mutation
the unborn, developing young of an animal during the later stages of development
fetus
a protein, produced by the immune system, that either attacks invading pathogens or marks them for killing
antibody
an organism in the early stages of development
embryo
a substance that can speed up the rate of a chemical reaction without being changed or used up during the reaction
catalyst
the basic unit of structure and function that makes up all organisms
cell
a condition in which a person’s immune system is overly sensitive to environmental substances that are normally harmless
allergy
the process by which organisms produce new organisms of the same type
reproduction
any change in the environment that causes an organism to react
stimulus
pod-shaped organelles that contain enzymes used to extract energy from nutrients
mitochondria
the ability of an organism to maintain a stable internal environment even when the external environment changes
homeostasis
to copy
replicate
(deoxyribonucleic acid) the material found in all cells that contains genetic information about that organism
DNA
the body’s primary defense against disease-causing pathogens
immune system
a segment of DNA (on a chromosome) that contains the code for a specific trait
gene
any one of several building blocks of protein
amino acids
a thick threadlike structure that contains genetic information in the form of DNA
chromosome
a large structure within a cell that controls the cell’s metabolism and stores genetic information, including chromosomes and DNA
nucleus