Glossary Flashcards
the movement of digested food molecules through the wall of the intestine into the blood or lymph
absorption
the change of shape of the lens, in order to focus on objects at different distances
accommodation
the part of an enzyme molecule into which its substrate fits
active site
the movement of molecules and 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
active transport
a feature of an organism that helps it survive in its encironment
adaptation (adaptive feature)
tissue made up of cells in which fat is stored
adipose tissue
a hormone secreted by the ______ glands, which prepares the body for ‘flight or fight’
adrenaline
adrenal glands
the release of a relatively large amount of energy in cells by the breakdown of nutrient molecules in the presence of oxygen
aerobic respiration
any of two or more alternative forms of a gene
allele
part of the digestive system; a long tube running from mouth to anus
alimentary canal
an air sac in the lungs, where gas exchange occurs
alveolus (plural: alveoli)
molecules that can link together in a long chains to form proteins; they contain carbon, hydrogen, oxygen and nitrogen and sometimes sulfur
amino acids
fluid secreted by the ______, which supports and protects a developing fetus
amniotic fluid
amnion
an enzyme which breaks down starch to maltose
amylase
the release of a relatively small amount of energy by the breakdown of nutrient molecules in the absence of oxygen
anaerobic respiration
the part of a stamen in which pollen is produced
anther
a drug that kills bacteria in the human body, without damaging human cells
antibiotic
chemicals secreted by lymphocytes, which attach to antigens andhelp to destroy them
antibodies
a blood vessel that carries blood away from the heart
artery
the choice by a farmer or grower of only the ‘best’ parents to breed, generation after generation
artificial selection
the process resulting in the production of genetically identical offspring from one parent
asexual reproduction
the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells
assimilation
valves between the atria and ventricles in the heart that prevent blood flowing from the ventricles into the atria
atrioventricular valves: tricuspid valves (right) bicuspid valves (left)
a plant hormone which causes cells to elongate
auxin
a nerve fibre that conducts impulses away from the cell body
axon
a diet containing some of each of the different types of nutrients, in a suitable quantity and proportions
balanced diet
a liquid made in the the liver, stored in the gall bladder and emptied into the small intestine, where it helps to emulsify fats
bile
a two-word Latin name for a species of organism, genus+species
biominal
a test for protein
biuret test
muscular movements which cause air to move into and out of the lungs
breathing
the small tubes into which the bronchi branch
bronchioles
one of the two tubes into which the trachea branches, carrying air into each lung
bronchus (plural: bronchi)
a tiny blood vessel that delivers blood to tissues
capillaries
an enzyme that catalyses the breakdown of carbohydrates
carbohydrase
starches and sugars
carbohydrates
the muscle of which the heart is made
cardiac muscle
an animal that gets its energy by eating other animals
canivore
the female part of a flower
carpel
a solution of sugars and other substances inside the vacuole of a plant cell
cell sap
a polysaccharide carbohydrate which forms fibres and is found in the cell walls of plant cells
cellulose
the brain and spinal cord
central nervous system
a thread-like structure of DNA, made up of a string of genes
chromosome
the partly-digested food, that moves from the stomach into the small intestine
chyme
tiny extensions on the surface of a cell, which can wave in unison and cause fluids to move
cilia
a ring of muscle around the lens, which can change its shape
ciliary muscle
a group of genetically identical organisms
clone
a situation in which both alleles in a heterozygote have an effect on the phenotype
codominance
all the organisms, of all the different species, living in an area at the same time
community
a light-sensitive cell in the retina, which responds to light of a particular colour
cone cell
an organism that gets its energy by feeding on other organisms
consumer
differences in the features of a group of organisms in each individual’s features can lie anywhere between two extremes
continuous variation
a condition in which the coronary arteries become partly blocked
coronary heart disease
the structure that forms in an ovary after an egg has been released; it secrets progesterone
corpus luteum
in a kidney, the outer layer; in a plant stem or root, a tissue made of typical plant cells (usually without chloroplasts)
cortex
food storage structures in ground during germination and begin to photosynthesise
cotyledons
the transfer of pollen from the anther of one plant to the stigma of another plant of the same species
cross-pollination
a layer of wax on a leaf
cuticle
jelly-like material that is found in cells
cytoplasm
a metabolic reaction that takes place in the liver in which amino acids is removed to form urea, followed by the release of energy from the remainder of the amino acid
deamination
a stage where the number in a population falls rapidly towards zero
death phase
an organism that gets its energy from dead or waste organic matter
decomposer
the desruction of large area of forest
deforestation
an enzyme is said to be _______when its molecule has changed shape so much that the substrate can no longer fit into it
denatured
bacteria that obtain their energy by converting nitrate ions into nitrogen gas
denitrifying bacteira
a drug that inhibits the nervous system and slows it down
depressant
exchange of substances through a partially permeable membrane; used in kidney faliure
dialysis
the net movement of molecules from a region of higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement
diffusion
the break-down of large, insoluble food molecules into small molecules using mechanical and chemical processes
digestion
having two sets of chromosomes
diploid
a complex sugar; a carbohydrate whose molecules are made of two sugar units
disaccharide
differences in the features of a group of organisms where each fits into one of a few clearly defined categories
discontinuous variation
the chemical which chromosomes and genes are made
DNA
an allele that is expressed if it is present; written in capital letter
dominant
a condition in which an organism shuts its metabolism down, so that it can survive in adverse condition
dormant
a system in which blood passes twice through the heart on one complete circuit of the body
double circulatory system
any substance taken into the body that modifies or affects chemical reactions in the body
drug
a unit containing all of the organisms and their environment, interacting together, in a given area
ecosystem
unable to regulate body temperature physiologically; the organism’s temperature varies with that of its environment
ecothermic
a part of the body that responds to a stimulus, a muscle or a gland
effector
the passing out of food that has not been digested, as faeces, through the anus
egestion
which is different from excretion
a female gamete
egg
a young organism before birth, and before all the body organs have formed
embryo
breaking large globules of fat into tiny droplets, so that they mix easily with water
emulsification
the ductless glands that secrete hormones into the blood and together make up the _______ system
endocrine glands
able to internally regulate body temperature; the body temperature is independent of the temperature of the environment
endothermic
the increase in the green house effect caused by the addition of more greenhouse gases to the atmosphere
enhanced greenhouse effect
proteins that function as biological catalysts
enzymes
the outer layer of the skin
epidermis (mammals)
a tissue made up of a single layer of cells which covers the top and bottom of a leaf, and the outside of the stem and root
epidermis (plant)
removal from organisms of the waste products of metabolism (chemical reactions in cells including respiration) toxic materials and substances in excess of requirements
excretion
the offspring from a parent homozygous for a dominant allele and a parent homozygous for the recessive allele
F1 generation
the stage in population growth when numbers increase exponentially
exponential/log phase
the change in adaptive features of a population over time, as a result of natural selection
evolution
the breakdown of glucose by yeast, using anaerobic respiration; it produces carbon dioxide and alcohol
fermentation
the fusion of the nuclei of two gametes
fertilisation
a young organism before birth, once all the body organs have formed
fetus
an insoluble protein that forms fibres that help in blood clotting
fibrin
a soluble protein that is converted to insoluble fibrin when blood clots
fibrinogen
the stalk of a stamen
filament
the probability of an organism surviving and reproducing in the environment in which it is found
fitness
a term used to describe a cell that has lost a lot of water, becoming soft
flaccid
a space inside an ovary in which an egg develops
follicle
a chart showing the flow of energy (food) from one organism to the next beginning with a producer
food chain
a network of interconnected food chains showing the energy flow through part of an ecosystem
food web
the part of the retina where cones are most tightly packed
fovea
an ovary of a plant after fertilisation; it contains seeds
fruit
a hormone secreted by the pituitary gland which causes the development of eggs in the ovaries
FSH - follicle stimulating hormone
able to let most substances pass through
fully permeable
sex cells
gamete
the entry of oxygen into an organism’s body, and the loss of carbondioxide
gas exchange
a length of DNA that is the unit of heredity and codes for a specific protein
gene
a change in the base sequence of DNA
gene mutation
taking a gene from one species and putting it into another species
genetic engineering
the genetic makeup of an organism in terms of the alleles present
genotype
a group of similar and related species
genus (plural: genera)
a tangle of blood capillaries in a Bowman’s capsule in the kidney
glomerulus
a hormone secreted by the pancreas, which increases blood glucose level
glucagon
the polysaccharide that is used as an energy store in animal cells and fungi
glycogen
cells which secrete mucus
goblet cells
a response in which a plant grows towards or away from gravity
geotropism
the warming effect of carbon dioxide, methane and other greenhouse gases, on the earth
greenhouse effect
a permanent increase in size and dry mass by an increase in cell number or cell size or both
growth
one of two sausage-shaped cells in the epidermis in plants, between which there is a hole called a stoma; can change shape to open and close the stoma
guard cell
the place where an organism lives
habitat
having one set of chromosomes
haploid
a blood vessel that transports blood from the digestive system to the liver
hepatic portal vein
an animal that gets its energy by eating plants
herbivore
the scar where a seed was attached to a fruit
hilum
the maintenance of a constant internal environment
homeostasis
the two chromosomes of a pair in a diploid cell; they have genes for the same features at the same positions
homologous chromosomes
having two identical alleles of a particular gene
homozygous - pure-breeding
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
hormone
a plant adapted to live in wet conditions
hydrophyte
having too much glucose in the blood
hyperglycaemia
having too little glucose in the blood
hypoglycaemia
the movement of a young embryo into the lining of the uterus, and its attachment there
implantation
taking substances into the body through the mouth
ingestion
