Unit 1A Vocab - Defining Life - 9th Grade

Biology

the branch of science that primarily deals with the structure, function, growth, evolution, and distribution of organisms

Biotic

the living component in an ecosystem

Abiotic

a non-living element of the environment that influences the way organisms and ecosystems function

Atom

the fundamental, smallest unit of matter that retains the properties of a chemical element

Molecule

a group of atoms bonded together

Cell

the structural, functional, and biological unit of all organisms

Unicellular

organisms consisting of one cell that performs all vital functions including metabolism, excretion, and reproduction

Multicellular

an organism that is made of many cells, such as plants, animals, and fungi

Cell Specialization

the process by which unspecialized cells become distinct cells with specific structures and functions to perform unique roles in a multicellular organism

Tissue

a group of cells that have similar structure and that function together as a unit

Organ

a collection of tissues that carries out a function or set of related ones

Organ system

a group of organs that work together to perform one or more major, complex functions within a multicellular organism

Organism

a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis

Homeostasis

the tendency not to stray from the range of favorable or ideal internal conditions

Negative Feedback Loop

a feedback in which the system responds to the perturbation in the opposite direction as the perturbation

Positive Feedback Loop

a feedback in which the system responds to the perturbation in the same direction as the perturbation

Environmental Stimulus

any aspect of an organism’s external or internal environment that causes a reaction or change in behavior

Responsiveness

the ability of a living organism to detect and react to changes or stimuli, caused by other living organisms

Metabolism

encompasses the various biochemical processes, reactions, and conversions that transform one form of energy to another (catabolic and anabolic processes).

Heredity

the passing of genetic factors from parents to offspring or from one generation to the next (biological inheritance)