Bio Test 1

Atom

The smallest unit of matter.

Molecule

Two or more atoms chemically bonded together.

Organelle

A specialized structure inside a cell that performs a specific job.

Cell

The smallest unit of life.

Tissue

A group of similar cells working together to perform a specific function.

Organ

A group of tissues working together to perform a specific function.

Organ System

A group of organs working together to perform major body functions.

Organism

An individual living thing.

Population

A group of organisms of the same species living in the same area.

Community

All the different populations living and interacting in a given area.

Ecosystem

A community of organisms combined with the nonliving environment they interact with.

Biosphere

All ecosystems on Earth where life exists.

Sequence of biological organization

Cells $\rightarrow$ tissues $\rightarrow$ organs $\rightarrow$ organ systems $\rightarrow$ organism.

Requirement for life classification

An organism must display all 7 characteristics of life.

Unicellular

Describing an organism consisting of only one cell.

Multicellular

Describing an organism composed of many specialized cells working together.

Metabolism

The sum of all chemical reactions occurring within an organism.

Anabolism

buildup reactions, turns into complex molecules

Catabolism

Chemical reactions that break down larger molecules into smaller ones.

Homeostasis

The maintenance of a stable internal environment despite external changes.

Negative feedback

A response mechanism that reverses a change to return conditions toward a normal set point.

Growth

An increase in the size or overall number of cells.

Development

Structural and functional changes that occur as an organism matures.

Sexual reproduction

A process where two parents contribute genetic material to produce offspring.

Asexual reproduction

A process where a single parent produces offspring without combining genetic material.

Stimulus

A change in the environment that triggers a reaction in an organism.

Response

An organism's reaction to an environmental change.

Evolution

Change in the inherited characteristics of populations over generations.

Adaptation

An inherited trait that enhances an organism's survival and reproduction in its environment.

Polarity of water

Unequal sharing of electrons between oxygen and hydrogen, creating slightly positive and negative regions.

Hydrogen bond in water

A weak attraction between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another.

Cohesion

The attraction between water molecules sticking to other water molecules.

Adhesion

The attraction between water molecules sticking to different surfaces or materials.

High specific heat

The requirement of a large amount of energy to raise the temperature of a substance.

High heat of vaporization

The requirement of a large amount of energy to convert liquid water into gas.

Universal solvent property of water

The ability to dissolve many solutes, allowing efficient transport of nutrients and wastes within organisms.

Density anomaly of ice

Hydrogen bonds expand and lock water molecules farther apart upon freezing, making solid ice less dense than liquid water.