AQA Biology GCSE Topic 1: Cell Biology - Key Definitions

29 question-and-answer flashcards covering the key definitions for AQA GCSE Biology Topic 1: Cell Biology.

What is active transport in cells?

The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient) using energy from respiration.

What is an adult stem cell?

A type of stem cell that can form many different types of cells.

What is agar jelly used for in biology?

A substance placed in petri dishes to culture microorganisms.

What is meant by cell differentiation?

The process where a cell becomes specialised for its function.

What is the function of the cell membrane?

It is a partially permeable barrier that surrounds the cell.

What is the cell wall and where is it found?

An outer layer made of cellulose that strengthens plant cells.

What is the role of chloroplasts?

They are organelles that are the site of photosynthesis.

What are chromosomes?

DNA structures found in the nucleus that are made up of genes.

What is a concentration gradient?

The difference in concentration between two areas.

Define diffusion.

The net movement of particles from an area of higher concentration to an area of lower concentration in gases or solutions.

What is an embryonic stem cell?

A stem cell that can differentiate into most types of human cells.

What is a eukaryotic cell?

A cell that contains a nucleus, found in plants and animals.

What does magnification mean in microscopy?

How much bigger an image appears compared to the original object.

What are meristematic cells?

Plant stem cells that can differentiate into any type of plant cell.

What is the main function of mitochondria?

They are organelles that are the site of respiration.

What is mitosis?

A type of cell division that produces two genetically identical daughter cells from one parent cell.

What is the nucleus in a cell?

An organelle containing genetic material that controls the cell’s activities.

What is an organelle?

A specialised structure found inside a cell.

Define osmosis.

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

What is a plasmid?

A loop of DNA found in the cytoplasm of prokaryotic cells.

What characterises a prokaryotic cell?

A cell that does not contain a nucleus, found in bacteria.

What does resolution refer to in microscopy?

The ability to distinguish two different points in a specimen.

What are specialised cells?

Cells that are adapted to perform a specific function.

Define a stem cell.

An undifferentiated cell that can divide to produce many specialised cells of the same type.

What is surface area in biology?

The amount of contact an object has with its environment.

What is the surface area to volume ratio (SA:V)?

The size of an object compared with the amount of area where it contacts its environment.

What is the cell cycle?

A series of stages preparing a cell for division.

What is therapeutic cloning?

Producing an embryo that has the same genes as a patient.

What is a vacuole in plant cells?

An organelle that stores cell sap.