AP Biology Unit 2 Topic 1: Cellular structure and functions

What to Know

Identify the system, surroundings, and scale before explaining a process.
Use diagrams, graphs, and tables as evidence rather than decoration.
For quantitative questions, keep units visible from the setup through the final answer.
Always connect this topic back to the larger unit: Cells.

Detailed Notes

Cellular structure and functions belongs to Cells, so study it as part of a larger scientific system rather than as a stand-alone fact. Start by identifying what is being described, what is changing, and what evidence would let you defend a claim.

In AP Biology, strong answers usually connect a visible pattern to an underlying mechanism. That means explaining not only what happens, but why it happens at the particle, organism, environmental, or system level.

For AP-style questions, expect this topic to appear with graphs, diagrams, data tables, experiments, or written scenarios. Your job is to describe the evidence, apply the correct concept, and explain the reasoning that connects them.

Key Vocabulary

Cell

The basic unit of life; all organisms are made of one or more cells.

Organelle

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

Plasma membrane

The selectively permeable boundary that controls movement into and out of the cell.

Cytoplasm

The fluid-filled region inside the cell where many cellular processes occur.

Eukaryotic cell

A cell with a nucleus and membrane-bound organelles.

Prokaryotic cell

A cell without a nucleus or membrane-bound organelles, such as a bacterial cell.

Quick Practice

How would you explain Cellular structure and functions in one or two AP-style sentences?

Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.