keywords Flashcards
light microscope
an instrument used to magnify specimens using lenses and light
electron microscope
an instrument used to magnify specimens using a beam of electrons
nucleus (of a cell)
an organelle found in many living cells containing the genetic information
gene
a short section of DNA carrying genetic information
chromosome
thread-like structure carrying the genetic information found in the nucleus of a cell
cytoplasm
the water-based gel in the which the organelles of all living cells are suspended
cell membrane
the membrane around the contents of a cell which controls what moves in and out of the cell
mitochondria
the site of aerobic cellular respiration in a cell
ribosome
the site of protein synthesis in a cell
protein synthesis
the process by which proteins are made on the ribosomes based on information from the genes in the nucleus
algae
single-celled or simple multicellular organisms, which can photosynthesize but are not plants
algal cell
the cells of algae, single-celled or simple multicellular organisms, which can photosynthesize but are not plants
cell wall
a rigid structure which surrounds the cells of living organisms apart from animals
cellulose
a big carbohydrate molecule which makes up plant and algal cell walls
chloroplasts
the organelles in which photosynthesis takes place
chlorophyll
the green pigment contained in the chloroplasts
permanent vacuole
a space in the cytoplasm filled with cell sap which is there all the time
bacteria
single-celled microorganisms that can reproduce very rapidly. Many bacteria are useful, e.g. gut bacteria and decomposing bacteria, but some cause disease
bacterial colony
a population of billions of bacteria grown in culture
genetic material
the DNA which carries the instructions for making a new cell or a new individual
DNA
deoxyribonucleic acid, the material of inheritance
plasmid
extra circle of DNA found in bacterial cytoplasm
yeast
single-celled fungi which produce ethanol when they respire carbohydrates anaerobically
asexual budding
a form of asexual reproduction where a complete new individual forms as a bud on the parent organism
aerobic respiration
breaking down food using oxygen to release energy for the cells
anaerobic respiration
breaking down food without oxygen to release energy for the cells
fermentation
the reaction in which the enzymes in yeast turn glucose into ethanol and carbon dioxide
antibiotic
drug that destroys bacteria inside the body without damaging human cells
specialized
adapted for a particular function
optic nerve
the nerve carrying impulses from the retina of the eye to the brain
root hair cell
cell on the root of a plant with microscopic hairs which increases the surface area for the absorption of water from the soil
xylem tissue
the non-living transport tissue in plants, which transports water around the plant
mineral ion
chemical needed in small amounts as part of a balanced diet to keep the body healthy
sperm
male sex cell (gamete) in animals
diffusion
the net movement of particles of gas or a solute from an area of high concentration to an area of low concentration (along a concentration gradient)
solute
the solid which dissolves in a solvent to form a solution
net movement
the overall movement of
concentration gradient
the gradient between an area where a substance is at a high concentration and a area where it is at a low concentration
simple sugars
small carbohydrate molecules made up of single sugar units or two sugar units joined together
respiration
the process by which food molecules are broken down to release energy for the cells
partially permeable membrane
allowing only certain substances to pass through
osmosis
the net movement of water from an area of high concentration (of water) to an area of low concentration (of water) along a concentration gradient
isotonic
having the same concentration of solutes as another solution
hypertonic
a solution with a higher concentration of solute molecules than another solution
hypotonic
a solution with a lower concentration of solute molecules than another solution
turgor
the state of a plant cell when the pressure of the cell wall on the cytoplasm cancels out the tendency for water to move in by osmosis, so the cell is rigid
plasmolysis
the state of a plant cell when large amounts of water have moved out by osmosis and the protoplasm shirks and pulls away from the cell wall, leaving visible gaps
active transport
the movement of substances against a concentration gradient and / or across a cell membrane, using energy
kidney tubule
a structure in the kidney where substances are reabsorbed back into the blood
exchange surface
a surface where materials are exchanged
ventilated
movement of air into and out of the lungs
gaseous exchange
the exchange of gases, e.g. the exchange of oxygen and carbon dioxide which occurs between the air in the lungs and the blood
alveoli
the tiny air sacs in the lungs which increase the surface area for gaseous exchange
stomata
openings in the leaves of plants (particularly the underside) which allow gases to enter and leave the leaf. They are opened and closed by guard cells
digestive system
the organ system, running from the mouth to the anus, where food is digested
small intestine
the region of the digestive system where most of the digestion of the food takes place
