science exam

What is a cell?

The basic structural, functional, and biological unit of all known organisms.

What is an organelle?

A specialized subunit within a cell that has a specific function.

Nucleus

An organelle that contains the cell's genetic material (DNA) and controls the cell's growth and reproduction.

Mitochondria

Often called the "powerhouses" of the cell, these organelles generate most of the chemical energy needed to power the cell's biochemical reactions, stored in adenosine triphosphate (ATP).

Cell Membrane

A biological membrane that separates the interior of all cells from the outside environment, protecting the cell and controlling what goes in and out.

Cytoplasm

The jelly-like substance that fills the cell and surrounds the organelles.

What is a variable in research?

Any factor, trait, or condition that can exist in differing amounts or types and is measurable.

Quantitative Variables

Variables that can be measured numerically and express a quantity or amount. Examples include age, height, weight, and temperature.

Qualitative Variables (Categorical Variables)

Variables that represent categories or types and cannot be measured numerically. They describe qualities or characteristics. Examples include gender, race, and hair color.