Edexcel Biology GCSE Topic 2: Cells and Control

A set of vocabulary flashcards covering key definitions and concepts in Edexcel Biology GCSE Topic 2: Cells and Control.

Adult stem cells

Stem cells that can differentiate into a limited range of cell types, e.g. bone marrow stem cells.

Anaphase

The third stage of mitosis in which the chromatids are pulled to opposite poles of the cell by spindle fibres.

Asexual reproduction

A form of reproduction involving a single parent that creates genetically identical offspring.

Axon

A long fibre that conducts nerve impulses away from the cell body.

Cancer

A non-communicable disease caused by changes in the cell that lead to uncontrolled growth and division.

Cataract

A cloudy patch which forms on the lens of the eye preventing normal light entry, leading to blurred vision.

Cell cycle

A series of events that take place in a cell, involving cell growth, DNA replication, and cell division.

Cell differentiation

The process by which an undifferentiated cell becomes specialised for its function.

Cell elongation

The process by which cells expand and enlarge, enabling the growth of a plant.

Central nervous system (CNS)

The brain and spinal cord.

Cerebellum

The region of the brain that controls muscle coordination and non-voluntary movement.

Cerebral hemisphere

One half of the cerebrum that controls muscles on opposite sides of the body.

Cerebrum

The largest region of the brain responsible for movement, memory, intelligence, language, and vision.

Chromatid

One ‘arm’ of a replicated chromosome.

Chromosome

A long, coiled molecule of DNA that carries genetic information in the form of genes.

Colour blindness

A deficiency of the eye that makes it difficult to distinguish between colours.

Cone cells

Cells found in the retina sensitive to bright light and detecting different colours.

Cornea

The transparent outer covering that reflects light entering the eye.

CT scan

An imaging technique using X-rays to create detailed images of internal organs.

Cytokinesis

The division of the cytoplasm at the end of mitosis to produce two new daughter cells.

Dendrites

Short, branched extensions that receive nerve impulses from other neurones.

Dendron

Branched extensions of a nerve cell that carry impulses towards the body.

Diploid cell

A cell that contains two copies of each chromosome.

Effector

An organ, tissue, or cell that produces a response to a stimulus.

Embryonic stem cells

Stem cells found in very early embryos, capable of differentiating into any cell type.

Eye

A sense organ containing receptors sensitive to light intensity and colour.

Growth

An increase in mass or size.

Haploid cell

A cell that contains a single copy of each chromosome.

Interphase

The longest stage of the cell cycle involving cell growth and DNA replication.

Iris

A pigmented ring of muscles controlling the size of the pupil.

Lens

A transparent, biconvex structure that refracts light onto the retina.

Long-sightedness

A defect where nearby objects appear out of focus due to light convergence behind the retina.

Medulla oblongata

The brain region regulating unconscious activities like breathing and heart rate.

Meristem tissue

Plant tissues containing undifferentiated stem cells.

Metaphase

The second stage of mitosis where chromosomes align at the cell equator.

Mitosis

A form of cell division producing two genetically identical daughter cells.

Motor neurone

A neurone carrying nerve impulses from the CNS to the effectors.

Myelin sheath

An insulating layer surrounding the axon that increases the speed of nerve impulses.

Neurones

Nerve cells that transmit nerve impulses, the functional units of the nervous system.

Neurotransmitters

Chemicals used for communication between neurones and target cells.

Percentile chart

A chart used to monitor growth by comparing measurements to expected values.

PET scan

An imaging technique assessing brain structure and function through radioactive chemicals.

Prophase

The first stage of mitosis where chromosomes condense and the nuclear membrane breaks down.

Pupil

A hole in the centre of the iris allowing light rays to enter the eye.

Reflex

A rapid and automatic response to a stimulus by the body.

Reflex arc

The pathway of neurones involved in a reflex action.

Relay neurone

A neurone carrying nerve impulses from sensory to motor neurones within the CNS.

Retina

A light-sensitive layer at the back of the eye that converts light energy into neural signals.

Rod cells

Cells in the retina sensitive to low light intensity.

Sensory neurone

A neurone that carries nerve impulses from receptors to the CNS.

Sensory receptor

A specialised structure detecting a specific type of stimulus.

Short-sightedness

A defect of the eye causing distant objects to be out of focus due to light convergence in front of the retina.

Stem cells

Cells that are unspecialised and capable of differentiating into various cell types.

Synapse

A small gap between neurones where nerve impulse transmission occurs.

Telophase

The final stage of mitosis where spindle fibres break down and daughter cell nuclei form.