Cell Theory and Organisms Study Guide

A set of vocabulary flashcards covering the fundamentals of cell theory, cell functions, and the differences between unicellular and multicellular organisms.

What is the basic unit of all living organisms?

The cell

According to cell theory, what are all living things made of?

One or more cells

Why is the cell considered the basic unit of life?

Because it is the smallest structure capable of carrying out all life functions.

Major Cell Functions

The four essential tasks every cell must perform to stay alive: obtain nutrients and water, remove waste, obtain and use energy, and respond to the environment.

Unicellular Organisms

Organisms consisting of a single cell that performs all the functions necessary for life.

Multicellular Organisms

Organisms consisting of many cells where labor is divided among specialized cells to perform specific functions more efficiently.

Cell Specialization

The process in multicellular organisms where different cells perform specific tasks, such as muscle cells contracting or nerve cells transmitting signals.

Cell Division

The process where one cell grows, copies its contents, and divides into two new cells, allowing for growth, tissue repair, and reproduction.

Microscopic

A term used to describe objects, such as most cells, that are too small to be seen with the naked eye.

Microscope

The instrument used by scientists to observe cells and other microscopic structures.

Preexisting Cells

The existing cells from which all new cells are produced, contradicting the idea that cells can arise from nonliving matter.