Biology: Cell Structure and Function

Study Notes

Cell Size and Structure

Cells are small because their volume increases faster than their surface area.
Small cells more efficiently move nutrients and waste.
Cell size is limited by surface area-to-volume ratio, material movement, and DNA efficiency.

Cell Cycle

S phase: DNA replicates.
Mitosis: The nucleus divides.
Cytokinesis: The cell divides into two.

Cell Theory

All living things are made of cells.
Cells are the fundamental unit of life.
New cells arise from existing cells.

Cell Types

Plant cells have a cell wall and chloroplasts.
Animal cells do not have these structures.
Both plant and animal cells contain cell membranes and mitochondria.

Cell Membrane

Made of fats with water-loving heads and water-fearing tails.
Controls what enters and exits the cell.

Protein Production

Ribosomes synthesize proteins.
The Golgi apparatus packages proteins.

Evolution and Natural Selection

Species change over time due to natural selection.
Example: Birds with longer beaks survive if food is deep in trees.

Speciation

Geographic isolation occurs when a barrier separates a group.
Reproductive isolation develops when groups stop interbreeding.

Mutations

Mutations are changes in DNA.
Mutations drive evolution by creating variation.

Darwin's Observations

Island animals resemble mainland relatives but adapt to their new environments.

Classification and Characteristics of Life

Scientific names (e.g., Felis catus) classify organisms.
Archaea and bacteria are single-celled, with differences in cell walls.
Characteristics common to all life forms:
- Composed of cells.
- Respond to surroundings.
- Grow, reproduce, and use energy.
Kingdom distinctions:
- Animals move and cannot produce their own food.
- Plants remain stationary and generate food using sunlight.

Description

This quiz covers essential concepts in cell biology, including cell size and structure, the cell cycle, cell theory, and different cell types. Test your understanding of how cells operate and their vital roles in living organisms.