Download glossary - Skinners` School Physics

Glossary
abdomen
lower part of the body in humans, between the ribs and
hip bones
absorption
movement of digested food molecules through the wall
of the intestine into the blood or lymph
acid rain
Air pollution produced when acid chemicals are
incorporated into rain, snow, fog or mist. The "acid" in
acid rain comes from sulfur oxides and nitrogen oxides,
products of burning coal and other fuels and from certain
industrial processes.
active transport
movement of ions in or out of a cell through the cell
membrane, from a region of their lower concentration to
a region of their higher concentration against a
concentration gradient, using energy released during
respiration
adaptation
features of living things that help them survive in their
environment
aerobic respiration
the release of a relatively large amount of energy in cells
by the breakdown of food substances in the presence of
oxygen
alimentary canal
the passage along which food passes through the body,
from mouth to anus
allele
alveoli
amino acid
amnion
one of two or more alternative forms of a gene
air sacs in the lungs through which gas exchange takes
place
the basic building block of proteins
the innermost membrane enclosing the embryo
amniotic fluid
the fluid surrounding the developing fetus that is found
within the amniotic sac contained in the mother's womb
amylase
a digestive enzyme, produced largely by the pancreas
and salivary glands, which converts starches to sugars
anaemia
below normal levels of red blood cells or haemoglobin,
or both, which can be caused by many different
conditions, including iron deficiency
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anaerobic
respiration
anther
the release of a relatively small amount of energy by the
breakdown of food substances in the absence of oxygen
pollen-producing oval body at the tip of a stamen
antibiotic
a class of natural and synthetic compounds that inhibit
the growth of, or kill, other micro-organisms
antioxidant
a molecule that is capable of reacting with free radicals
and neutralising them
anus
the opening to the anal canal
aorta
the largest artery; it leaves the heart
artery
blood vessel that carries blood away from the heart
arteriole
artificial selection
small, elastic blood vessel that arises from arteries and
leads into capillaries
selective breeding
asexual
reproduction
the process resulting in the production of genetically
identical offspring from one parent
assimilation
making use of molecules that have been absorbed from
food
atom
a chemical unit that is the smallest particle of an element
still retaining its properties
auxin
a type of plant hormone that elongates cells in
seedlings, shoot tips, embryos and leaves
axon
part of a neurone that allows electrical signals to pass
through
bacteria
bile
very small single-celled organisms
a liquid produced by the liver that helps in digestion of
fats
bile duct
the passage from the liver to the duodenum
bile salts
salts in the bile that help break fat into tiny droplets
binomial
a system in which the scientific name of an organism is
made up of two parts showing the genus and species
biodegradable
able to be broken down by bacteria and other microorganisms
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biomass
bolus
bronchi
bronchioles
canines
capillaries
the mass of a living organism
a ball of food
tubes through which air passes, between the trachea
and the smaller bronchioles
small tubes that branch from each of the bronchi
pointed teeth used for biting
tiny blood vessels
carbohydrase
enzyme that digests carbohydrate
carbon dioxide
gas produced during respiration and used up during
photosynthesis
carnivore
an animal that gets its energy by eating other animals
catalyst
a substance that speeds up a chemical reaction and is
not changed by the reaction
cell wall
the outer part of a plant cell, made of cellulose
cell
cervix
the basic ‘building block’ of living things
the neck of the womb
chlorophyll
green pigment in plants, involved in photosynthesis
chloroplasts
structures containing chlorophyll
chromosome
a thread of DNA, made up of a string of genes
ciliary muscles
codominant
colon
community
concentration
gradient
cones
consumer
ring of muscles holding the eye lens
alleles both having an effect in a heterozygous organism
first part of the large intestine
all the different species in a habitat
a difference in concentration across a material
light-sensitive cells in the retina, responsible for colour
vision
an organism that gets its energy by feeding on other
organisms
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contraction
cornea
coronary heart
disease
coronary arteries
crustaceans
cytoplasm
deamination
decomposers
deficiency disease
in muscle tissue, the shortening of cells
the front of the eye, responsible for most of the focusing
disease in which the coronary arteries get blocked or
damaged
arteries that deliver blood to the heart muscles
a group of arthropods including crabs, shrimp and
woodlice
jelly-like substance in cells
removal of nitrogen from amino acids
an organism that gets its energy from dead or waste
organic matter
disease caused by lack of a particular nutrient
denaturing
breakdown of an enzyme caused by a high temperature
dendrites
threads of cytoplasm in a neurone that pick up electrical
signals
denitrifying bacteria
bacteria that turn ammonia and nitrates back to nitrogen
dialysis
diaphragm
filtering a patient’s blood in a similar way to a kidney
muscular sheet below the ribs and lungs
diffusion
the net movement of molecules from a region of their
higher concentration to a region of their lower
concentration down a concentration gradient, as a result
of their random movement
digestion
the breakdown of large, insoluble food molecules into
small, water-soluble molecules using mechanical and
chemical processes
diploid nucleus
a nucleus containing two sets of chromosomes (e.g. in
body cells)
DNA
deoxyribonucleic acid, the molecule from which genes
are composed
dominant
an allele that is expressed if it is present (e.g. T or G)
double circulatory
system
a system in which the blood goes through the heart
twice
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drug
any substance taken into the body that modifies or
affects chemical reactions in the body
duodenum
first part of the small intestine
ecosystem
a unit containing all of the organisms and their
environment, interacting together, in a given area e.g.
decomposing log or a lake
effectors
parts of the body that respond to changes
egestion
passing out of food that has not been digested through
the anus as faeces
embryo
an unborn offspring during the first eight weeks after
conception
emphysema
condition of the lungs causing breathlessness
endocrine system
communication system that uses hormones
enzymes
proteins that function as biological catalysts
epidermis
layers of cells at the surface of a leaf
eutrophication
lack of oxygen in water caused by excessive plant
nutrients
evolution
process by which different kinds of organism develop
from earlier ones
excretion
removal from organisms of toxic materials, the waste
products of metabolism (chemical reactions in cells
including respiration) and substances in excess of
requirements
exoskeleton
faeces
Fallopian tube
hard outer covering of the body
waste products of digestion
tube leading from the ovary to the uterus, through which
an egg must pass
fatty acids
part of a fat molecule
fertilisation
process by which a sperm combines with an egg
fetus
an unborn offspring after the first eight weeks after
conception
fibre
roughage in the diet
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fibrin
an insoluble protein that gets tangled up with blood cells
to produce a blood clot
fibrinogen
a soluble protein in blood plasma
food chain
a chart showing the flow of energy (food) from one
organism to the next, beginning with a producer (e.g.
mahogany tree → caterpillar → song bird → hawk)
food web
a network of interconnected food chains showing the
energy flow through part of an ecosystem
fossil fuels
fuels such as coal, oil and gas formed from remains of
living things that existed millions of years ago
gall bladder
bile is stored in the gall bladder
gametes
gastric juice
genes
genetic engineering
male or female germ cell (a sperm or egg)
fluid that mixes with food in the stomach
A length of DNA that is the unit of heredity and contains
codes for a specific protein. A gene may be copied and
passed on to the next generation.
taking a gene from one species and putting it into
another species
genotypes
genetic makeup of an organism in terms of the alleles
present (e.g. Tt or GG)
geotropism
a response in which a plant grows towards or away from
gravity
glucagon
hormone that increases blood glucose concentration
glucose
a type of sugar
glycogen
a polysaccharide, used as an energy store
growth
guard cells
haemoglobin
haploid nucleus
a permanent increase in size and dry mass, by an
increase in cell number or cell size, or both
in a leaf, the guard cells change shape to open or close
the stomata
a protein in blood, responsible for carrying oxygen
a nucleus containing a single set of unpaired
chromosomes (e.g. sperm and egg)
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herbivore
an animal that gets its energy by eating plants
hermaphrodite
having both male and female characteristics
heterozygous
having two different alleles of a particular gene (e.g. Tt
or Gg), not pure-breeding
homeostasis
the maintenance of a constant internal environment
homozygous
Having two identical alleles of a particular gene (e.g. TT
or gg). Two identical homozygous individuals that breed
together will be pure-breeding.
hormones
a chemical substance, produced by a gland, carried by
the blood, which alters the activity of one or more
specific target organs and is then destroyed by the liver
hyphae
ileum
immunosuppressant
drugs
incisors
ingestion
inheritance
inorganic
insulin
intercostal muscles
iris
kidney tubules
kwashiorkor
lactase
lactic acid
lactose
threads making up the main body of a fungus
latter part of the small intestine
substance taken into the body that modifies or affects
chemical reactions in the body
biting teeth
taking substances (e.g. food, drink) into the body
through the mouth
the transmission of genetic information from generation
to generation
substances that do not derive from living things
hormone that helps reduce a high blood glucose level
muscles between the ribs
coloured part of the eye that changes shape to control
amount of light entering the eye
tiny tubes in the kidney that play a role in filtering the
blood
condition caused by lack of protein in the diet
enzyme that breaks down lactose
a waste product of anaerobic respiration
a type of sugar
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large intestine
part of the intestine where remaining water and
inorganic ions pass into the blood
limiting factor
something present in the environment in such short
supply that it restricts life processes
lipases
enzymes that break down fats
lipids
an alternative name for fats
lumen
space in the veins through which blood flows
lymph
tissue fluid in the lymphatic capillaries
lymphocytes
white blood cells that kill pathogens
malaria
disease caused by a parasite carried by mosquitoes
maltase
enzyme that breaks down maltose
maltose
a type of sugar
meiosis
reduction division in which the chromosome number is
halved from diploid to haploid
menstrual cycle
menstruation
mesophyll
metabolic reactions
micropyle
process of menstruation and ovulation
discharge of blood from the lining of the uterus
inner tissue of a leaf
chemical reactions that take place in cells
small opening in the surface of an ovule
mitosis
nuclear division giving rise to genetically identical cells in
which the chromosome number is maintained by the
exact duplication of chromosomes
molars
grinding teeth
mutation
a change in a gene or chromosome
mycelium
the main body of a fungus
myriapod
an arthropod with many legs
narcotic
addictive drug
nerve cell
cell that carries electrical signals
neurone
alternative name for a nerve cell
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nicotine
nitrifying bacteria
nitrogen-fixing
bacteria
addictive drug found in tobacco
bacteria that change proteins in organic material into
ammonia and nitrates
bacteria that change nitrogen from the air into ammonia
nucleus
part of a cell that contains genetic material
nutrition
taking in of nutrients that are organic substances and
mineral ions, containing raw materials or energy for
growth and tissue repair, absorbing and assimilating
them
obesity
condition of being severely overweight
oesophagus
tube connecting mouth and stomach
oestrogen
hormone that controls development of female
characteristics
optic nerve
nerve connecting retina to brain
organ
a structure made up of a group of tissues working
together to perform specific functions
organ systems
a group of organs with related functions, working
together to perform body functions
organic
derived from living things
osmosis
the diffusion of water molecules from a region of their
higher concentration (dilute solution) to a region of their
lower concentration (concentrated solution), through a
partially permeable membrane
ovary
the organ in which eggs (ova) are produced
oviduct
tube through which an egg leaves the ovary
ovulation
process by which an egg is released from the ovary
ovules
part of the ovary of a plant; becomes the seed after
fertilisation
oxygen debt
condition after exercise during which extra oxygen is
needed to break down lactic acid
oxyhaemoglobin
molecule formed when haemoglobin combines with
oxygen
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palisade cells
pancreas
pancreatic juice
partially permeable
cells near the surface of a leaf where most of the
photosynthesis takes place
gland containing pancreatic juice
fluid containing enzymes that help digestion
allowing some substances through, but not others
pathogen
a harmful organism
pectinase
enzyme that helps to break down cell walls in fruit
penicillin
an antibiotic
pepsin
peristalsis
a protein-digesting enzyme
process by which muscles in the wall of the intestine
cause food to be pushed along
phagocytes
white blood cells that surround and digest harmful
bacteria
phenotype
the physical or other features of an organism due to both
its genotype and its environment (e.g. tall plant or green
seed)
phloem tubes
photosynthesis
phototropism
placenta
plasma
tubes that transport sugars around a plant
the fundamental process by which plants manufacture
carbohydrates from raw materials using energy from
light
a response in which a plant grows towards or away from
the direction from which light is coming
organ in the uterus that provides nutrients for the fetus
watery constituent of blood that contains many dissolved
substances
plasmolysed
condition when the surface membrane of a plant cell is
pulled away from the cell wall
pollination
the transfer of pollen grains from the male part of the
plant (anther of stamen) to the female part of the plant
(stigma)
population
a group of organisms of one species, living in the same
area at the same time
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primary consumer
producers
protease
protein
an animal that eats plants
an organism that makes its own organic nutrients,
usually using energy from sunlight, through
photosynthesis
an enzyme that breaks down protein
molecules made up of amino acids
pulmonary artery
blood vessel from the heart to the lungs
pulmonary vein
blood vessel from the lungs to the heart
recessive
reflex action
reflex arc
reproduction
respiration
an allele that is only expressed when there is no
dominant allele of the gene present (e.g. t or g)
action that does not involve conscious thought (e.g.
blinking)
pathway from receptor to muscle
the processes that make more of the same kind of
organism
the chemical reactions that break down nutrient
molecules in living cells to release energy
retina
light-sensitive part of the eye
rods
light-sensitive cells in the retina, responsible for
monochrome vision in poor light
root hair cells
secondary
consumer
sense organs
specialised cells that help anchor a plant and absorb
water and minerals from the soil
an animal that eats other animals
groups of receptor cells responding to specific stimuli:
light, sound, touch, temperature and chemicals
sensitivity
the ability to detect or sense changes in the environment
(stimuli) and to make responses
sexual reproduction
the process involving the fusion of haploid nuclei to form
a
diploid zygote and the production of genetically
dissimilar offspring
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sickle cell anaemia
a condition causing abnormal haemoglobin, but which
appears to give protection against malaria
small intestine
part of the alimentary canal between the stomach and
the large intestine
sperm
spongy mesophyll
(layer)
stomata
suspensory
ligaments
tendon
tertiary consumer
test cross
testes
testosterone
the male sex cell
inner layer of a leaf, having air spaces between the cells
gaps in the lower epidermis of a leaf
strong fibres holding the eye lens within the ciliary
muscles
bundle of strong, non-stretchy fibres that hold muscle to
bone
an animal that eats a secondary consumer
crossing an unknown genotype with one showing a
recessive phenotype
organ that produces sperm
hormone that controls development of male secondary
sexual characteristics
thorax
in humans, the chest
tissue
a group of cells with similar structures, working together
to perform a shared function
trachea
tube between the mouth or nose and the bronchi
translocation
the movement of sucrose and amino acids in phloem
transpiration
evaporation of water at the surfaces of the mesophyll
cells followed by loss of water vapour from plant leaves,
through the stomata
trophic level
the position of an organism in a food chain, food web or
pyramid of biomass, numbers or energy
tropisms
turgid
urea
plant growth in response to a stimulus
rigid (in plants, when they have sufficient water)
an excretory substance made in the liver from excess
proteins, excreted by the kidneys
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ureter
tube carrying urine from the kidney to the bladder
urethra
tube through which urine leaves the body
uterus
organ in which offspring grow and develop before birth
vacuole
vascular bundles
veins
vena cava
villi
liquid-filled space inside a cell
structures in a leaf that contain xylem vessels
blood vessels carrying blood to the heart
the vein carrying blood from all of the body, apart from
the lungs, to the heart
small projections on the wall of the small intestine
water potential
a measure of concentration; concentrated solutions have
a low water potential
xylem vessels
a system of tubes that delivers water to parts of a plant
zygote
a cell resulting from the fusion of two gametes
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