Topic 1: Cell Biology

What are the two main types of cells?

Prokaryotic (e.g. bacteria) and eukaryotic (e.g. animal and plant cells).

Name three organelles found in both animal and plant cells.

Cell membrane, cytoplasm, nucleus.

What additional structures are found only in plant cells?

Chloroplasts, permanent vacuole, and cell wall (made of cellulose).

What are plasmids?

Small rings of DNA found in the cytoplasm of prokaryotic cells.

What is the function of mitochondria?

Site of aerobic respiration, providing energy for the cell.

How do sperm cells adapt for their function?

Streamlined shape, many mitochondria, and enzymes in the acrosome.

What is the role of xylem cells in plants?

Transport water and minerals from roots to shoots.

What is cell differentiation?

The process where a cell becomes specialised for its function.

What is the maximum magnification of a light microscope?

Around x2000.

Which microscope has a higher resolving power: light or electron?

Electron microscope (up to 0.2nm resolution).

What formula calculates magnification?

Magnification = size of image ÷ size of object.

What is binary fission?

The method by which bacteria reproduce by splitting in two.

Why are agar plates stored upside down?

To prevent condensation from disrupting bacterial growth.

What is mitosis used for?

Growth, repair, and asexual reproduction.

What are stem cells?

Undifferentiated cells that can become other types of cells.

Where are meristem stem cells found in plants?

In the tips of roots and shoots.

What is diffusion?

The passive movement of particles from high to low concentration.

What affects the rate of diffusion?

Concentration gradient, temperature, and surface area.

What is osmosis?

Movement of water from a dilute to a concentrated solution through a partially permeable membrane.

What is active transport?

Movement of substances against a concentration gradient using energy.