Biology Key Terms - Cells

Flashcards covering key vocabulary and concepts in cell biology, including definitions of terms related to cell structure and function, as well as processes such as transport and cellular differentiation.

Active transport

Movement of substances from an area of low concentration to an area of high concentration. Requires energy.

Agar

A jelly-like substance on which bacteria or fungi can be grown.

Animal cell

Cells which do not contain chloroplasts and don’t have a cell wall.

Antibiotic

Chemical used to kill bacteria inside the body.

Antiseptic

Chemical used to kill bacteria outside the body.

Aseptic technique

Used to ensure that microorganisms from the environment cannot contaminate an experiment and microorganisms from the experiment cannot escape into the environment.

Bacteria

Very small cells which don’t have a nucleus.

Binary fission

How bacteria divide and reproduce.

Bone marrow

In humans, where the adult stem cells which make blood cells are found.

Cell

The smallest unit of life.

Cell cycle

The complete life of a cell.

Cell membrane

Surrounds the cell and controls what moves into and out of the cell.

Cell sap

The liquid found in the vacuole of plant cells.

Cellulose

Plant cell walls are made of this.

Chloroplast

Cell organelle which carries out photosynthesis.

Chromosome

A length of DNA containing genes. Humans have 46.

Clone

A genetically identical organism e.g. plants grown from cuttings.

Colony

A group of bacteria growing on a medium e.g. agar.

Concentration gradient

A difference in concentration between two places.

Culture

A population of bacteria in a growth medium.

Cytoplasm

Liquid part of the cell, where chemical reactions occur.

Diabetes

A condition affecting the pancreas which might be treated using stem cells.

Differentiation

How a cell becomes specialised.

Diffusion

Movement of molecules from an area of high concentration to an area of low concentration.

Electron microscope

Type of microscope with a very high magnification and resolution.

Embryo

A source of stem cells for medical research and treatment.

Estimation

A ‘guess’ based on other facts e.g. working out the size of an organelle based on the size of others.

Gene

A length of DNA which codes for a protein.

Gills

Gas exchange surface in fish.

Glucose

Molecule which moves from the small intestine to the blood by active transport if it is only present as a low concentration.

Lungs

An organ containing alveoli to increase the surface area for diffusion.

Magnification

How much larger an object appears than it actually is.

Meristem

An area within plants where stem cells are found.

Microscope

A piece of equipment used to study very small objects e.g. cells.

Mineral ions

Substances which move from soil to roots by active transport.

Mitochondria

Cell organelle where respiration takes place.

Mitosis

Cell division to produce identical cells.

Muscle cell

A specialised cell in animals which can contract and relax as part of an organ with the same name.

Nerve cell

A specialised cell which carries impulses (signals) to and from the brain.

Nucleus

Cell organelle which contains DNA.

Nutrient broth

A liquid growth medium for bacteria.

Organ

A group of tissues carrying out a more complex role.

Organism

A living thing (usually made up of different tissues, organs and systems).

Osmosis

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

Oxygen

A gas which diffuses from the alveoli to the blood.

Partially permeable

Type of membrane needed for osmosis.

Permanent vacuole

Contains cell sap. Found in plant cells.

Phloem

Tissues in plants which transport sugars.

Plant cell

Cells which contain chloroplasts and have a cell wall.

Plasmid

A small ring of DNA found in a bacteria cell.

Ratio

A mathematical term to describe how many times larger/smaller one value is than another e.g. surface area and volume.

Replication

Happens to DNA before a cell can divide.

Resolution

The ability to distinguish between two points (e.g. in microscopy).

Ribosome

Cell organelle where protein synthesis (making proteins) takes place.

Root hair cell

A specialised cell in plants which has a long projection to increase the surface area for water absorption.

Small intestine

An exchange surface involved in transport of nutrients from digested food into the blood.

Specialised cell

A cell which is adapted to carry out a particular function.

Sperm cell

A specialised cell which carries genetic information from a male parent.

Stem cell

An unspecialised cell.

System

A group of organs working together for a specific function.

Therapeutic cloning

Process of producing stem cells for medical research which can then differentiate into different specialised cells.

Tissue

A group of specialised cells.

Urea

A chemical which diffuses from cells into blood plasma for excretion by the kidneys.

Xylem

Hollow tissues in plants which transport water.