CELLS AS THE BASIS OF LIFE

Stage 2 Biology

What is the cell theory?

All living things are made of cells. Cells are the basis units of life. New cells come from existing cells.

How are prokaryotic and eukaryotic cells different?

Prokaryotic cells are small and simple, with no nucleus. Eukaryotic cells are larger and have a nucleus and other organelles. Prokaryotes have circular DNA in the cytoplasm, eukaryotes have linear DNA inside the nucleus.

What does the nucleus do?

Holds the cell’s DNA and controls what the cell does.

What is the job of the mitochondria?

Makes energy for the cell (ATP).

Where does photosynthesis happen?

In the chloroplasts (only in plant cells).

What is the Golgi Body for?

Packages and sorts proteins to be sent around the cell.

Name two differences between plant and animal cells.

Plant cells have a cell wall and chloroplasts. Animal cells don't have a cell wall and chloroplasts.

What does ATP do in a cell?

Stores and gives energy for the cell’s activities.

What is the simple word equation for respiration?

glucose + oxygen → carbon dioxide + water + energy

Which releases more energy, aerobic respiration or fermentation?

Aerobic respiration. (Gives much more energy than fermentation)

What is the simple word equation for photosynthesis?

carbon dioxide + water → glucose + oxygen

Name one thing that affects how fast photosynthesis happens.

Light or temperature.

What does the cell membrane do?

Controls what goes in and out of the cell.

What is diffusion?

When particles move from where there’s a lot to where there’s less.

What do carrier proteins do?

They help transport molecules in and out of a cell.

Why does the cell copy its DNA before dividing?

So both new cells get the correct DNA.

What are the four steps of Mitosis?

Prophase, Metaphase, Anaphase, Telophase.

What is the main difference between mitosis and meiosis?

Mitosis makes two identical cells. Meiosis makes four different cells.

Why is meiosis important for variation?

It mixes up genes so offspring are different from parents.

What happens in fertilisation?

Male sperm cell fuses with female egg, creating a new full set of chromosomes.

How can chemicals affect cells?

Some chemicals can stop or slow down how cells work.

How do hormones help control cell division?

Some hormones tell cells when to divide or stop dividing.

What is cell culture used for?

Growing cells for research, making vaccines, testing medicines.

What is a problem with cell culture?

Cells might not act exactly the same as in the body.