topic 1 - cell biology

active transport

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

adult stem cell

A type of stem cell that can form many types of cell - undifferentiated

embryonic stem cell

a type of stem cell that can differentiate into most types of human cells - differentiated

cell differentiation

The process where a cell becomes specialised to its function.

cell membrane

a partially permeable barrier that surrounds the cell

cell wall

an outer layer made of cellulose that strengthens plant cells

chloroplast

an organelle which is the site of photosynthesis

chromosomes

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

concentration gradient

the difference in concentration between two areas.

diffusion

the net movement of particles from an area of high concentration to an area of low concentration

eukaryotic cells

a type of cell found in plants and animals that contains a nucleus

prokaryotic cells

a type of cell found in bacteria that does not contain a nucleus

magnification

how much bigger an image appears compared to the original object

meristematic cells

a type of stem cell that can differentiate into any type of plant cell (found in roots and shoots of plant)

mitochondria

an organelle which is the site of respiration

mitosis

a type of cell division which produces 2 genetically identical daughter cells from one parent cell (asexual)

nucleus

an organelle found in most eukaryotic cells that contains the genetic material of the cell, and controls the activities of the cell

organelle

a specialised structure found inside a cell

osmosis

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

plasmid

loops of DNA found in the cytoplasm of prokaryotic cells

resolution

the ability to distinguish 2 different points in a specimen

specialised cells

cells that are adapted to perform a specific function

stem cell

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

surface area

the amount of contact an object has with its environment

surface area to volume ratio (SA:V)

the size of the object compared with the amount of area where it contacts the environment

the cell cycle

a series of stages preparing the cell for division (interphase, mitosis, cytokinesis)

therapeutic cloning

producing an embryo that has the same genes as a patient

vacuole

an organelle that stores cell sap (plant)