Key Concepts in Human Biology and Physiology

A low number of red blood cells or low level of hemoglobin; may be caused by dietary deficiencies, metabolic disorders, hereditary conditions, or damaged bone marrow.

A foreign substance in the body that causes an immune response.

The BMR is the number of calories a person needs to perform normal bodily functions all day long.

The BMI is the result of a formula that uses your weight and height to determine whether you need to lose weight.

Energy-packed compounds consisting of carbon, hydrogen, and oxygen that provide quick fuel for organisms.

A form of carbohydrate that has a structural role in living organisms (animals and plants).

A machine that is used to separate blood cells and platelets from plasma.

Plant cells that use energy from sunlight to create food.

The fluid contained within animal cells. Also called plasma.

Carbohydrate molecules in which 2 monosaccharide molecules are joined together. Disaccharides consist of 6 to 14 carbon atoms.

Stands for deoxyribonucleic acid. Large molecules found in all living things that carry genetic information.

A high-powered, expensive device that uses beams of electrons to bring the finest details of cells into focus.

A system of glands that secrete different types of hormones that help regulate organisms.

The ER is a series of canals that connects the nucleus of animal cells to the cytoplasm outside those cells.

The state of a chemical reaction in which the amounts on each side of the reaction have stabilized.

Organisms — including plants and animals, as well as fungi, protozoa, and most algae — with cells that contain a nucleus and chromosomes.

A component within cells that packages and distributes hormones, enzymes, and other cell products to other organelles or outside the cell.

An iron-containing molecule in red blood cells that carries oxygen around the body.

Animals — including herbivores, carnivores, and omnivores — that feed on other living organisms.

The processes used by the body to constantly achieve and maintain balance.

The skin or outer surface of an animal. Small animals such as earthworms use integumentary exchange to exchange gases with the environment.

A method of describing the steps involved in the chemical process of respiration.

Compounds such as HDL and LDL that carry cholesterol through the bloodstream; made from a fat (lipid) and a protein.

Specialized cellular organelles formed by the Golgi apparatus that help to “clean up” the cell by breaking down harmful cell products and removing dead organelles.

A process, such as chewing, that physically breaks down food into pieces.

The extracellular fluid in which animal cells float.

An organelle in animal cells that combines food with oxygen to supply energy to cells.

Carbohydrate molecules in which simple sugars consist of three to seven carbon atoms.

A two-layer structure that separates the nucleus from the cytoplasm in animal cells.

Structures that float inside the fluid of cells; used during metabolic processes.

A mechanism that moves water and nutrients into and throughout a plant.

The action of food being moved down the esophagus and through the entire digestive tract.

Sacs of enzymes within animal cells that help protect the cell by breaking down accumulations of toxic products such as hydrogen peroxide.

The biochemical process that plants use to acquire energy from the sun.

The membrane that holds fluid within animal cells. Also called the cell membrane.

Carbohydrate molecules that are formed by many long chains of monosaccharides.

Organisms — such as bacteria and blue-green algae — with cells that do not contain a nucleus.

Components within cells that assist in making proteins from amino acids.

Stands for ribonucleic acid. In animals, works with DNA to produce proteins needed throughout the body.

Mammals — such as cattle, sheep, and goats — that can break down and digest cellulose.