Bio Keystones (copy 98-123)

:(

Mitosis

A nuclear division resulting in the production of two somatic cells having the same genetic complement as the original cell.

Molecule

The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms held together by chemical forces.

Monomer

A molecule of any compound that can react with other molecules of the same or different compound to form a polymer. Each biological macromolecule has characteristic monomers.

Multicellular

Made up of more than one cell.

Multiple Alleles

More than two forms of a gene controlling the expression of a trait.

Mutation

A permanent transmissible change of genetic material (e.g., chromosomal mutations and gene mutations).

Natural Selection

A process in nature in which organisms possessing certain inherited traits are better able to survive and reproduce compared to others of their species.

Nondisjunction

The process in which sister chromatids fail to separate during and after mitosis or meiosis.

Nonnative Species

A species normally living outside a distribution range that has been introduced through either deliberate or accidental human activity; also can be known as introduced, invasive, alien, nonindigenous, or exotic.

Nucleic Acid

A biological macromolecule (DNA or RNA) composed of the elements C, H, N, O, and P that carries genetic information.

Nucleus

A membrane‐bound organelle in eukaryotic cells functioning to maintain the integrity of the genetic material and, through the expression of that material, controlling and regulating cellular activities.

Organ

An anatomical unit composed of tissues serving a common function.

Organ System

An anatomical system composed of a group of organs that work together to perform a specific function or task.

Organelle

A subunit within a cell that has a specialized function.

Organic Molecule

A molecule containing carbon that is a part of or produced by living systems.

Organism

A form of life; an animal, plant, fungus, protist or bacterium.

Osmosis

The movement of water or another solvent through permeable membranes from an area of higher water concentration (dilute) to an area of lower water concentration (concentrated).

Passive Transport

The transportation of materials across a plasma membrane without using energy.

pH

The measure of acidity or alkalinity (basicity) of an aqueous solution scaling from 1 (highly acidic) to 14 (highly alkaline) with a midpoint of 7 (neutral)

Phenotype

The observable expression of a genotype.

Photosynthesis

A process in which solar radiation is chemically captured by chlorophyll molecules and through a set of controlled chemical reactions resulting in the potential chemical energy in the bonds of carbohydrate molecules.

Plasma Membrane

A thin, phospholipid and protein molecule bilayer that encapsulates a cell and controls the movement of materials in and out of the cell through active or passive transport.

Plastids

A group of membrane‐bound organelles commonly found in photosynthetic organisms and mainly responsible for the synthesis and storage of food.

Point Mutation

A single‐base substitution causing the replacement of a single‐base nucleotide with another nucleotide (e.g., silent mutation, in which there is no change in an amino acid; missense mutation, in which there is a different amino acid; and nonsense mutation, in which there is an insertion of a stop codon in the amino acid which stops protein synthesis).

Polygenic Trait

A trait in which the phenotype is controlled by two or more genes at different loci on different chromosomes.