Keywords Flashcards
(286 cards)
1
Q
Abiotic condition
A
A non-living feature of an ecosystem
2
Q
Abundance
A
The number of individuals of one species in a particular area (population size)
3
Q
Accurate result
A
A result that is really close to the true answer
4
Q
Acetylation
A
Attachment of an acetyl group to something (e.g. histones)
5
Q
Acetylcholine (ACh)
A
A type of neurotransmitter that binds to cholinergic receptors
6
Q
Acetyl Coenzyme A (AcetylCoA)
A
A type of coenzyme involved in respiration. It transfers acetate from one molecule to another
7
Q
Acquired mutation
A
A mutation you develop during your lifetime
8
Q
Actin
A
The thin myofilament protein in muscle fibres
9
Q
Actin-myosin cross bridge
A
The bond formed when a myosin head binds to an actin filament
10
Q
Activation energy
A
The energy that needs to be supplied before a chemical reaction will start
11
Q
Activator
A
A transcription factor that increases the rate of transpiration
12
Q
Active site
A
The part of an enzyme where a substrate molecule binds
13
Q
Active transport
A
Movement of molecules and ions across plasma membranes, usually against a concentration gradient. Requires energy
14
Q
Adaptation
A
The characteristic that increases an organism’s chance of survival and reproduction (e.g. abiotic resistance)
15
Q
ADP (adenosine diphosphate)
A
A molecule made up of adenine, a ribose sugar and two phosphate groups. ATP is synthesised from ADP and a phosphate group.
16
Q
Adrenaline
A
A hormone secreted from adrenal glands that has many effects, including increasing the blood glucose concentration
17
Q
Affinity for oxygen
A
The tendency a molecule has to bind with oxygen
18
Q
Agglutination
A
The clumping together of cells, e.g. pathogens, red blood cells
19
Q
AIDS (acquired immunodeficiency syndrome)
A
A condition caused by HIV, in which the immune system deteriorates and eventually fails
20
Q
Allele
A
One or more alternative versions of the same gene
21
Q
Allele frequency
A
How often an allele occurs in a population
22
Q
Allopatric speciation
A
Where speciation occurs as a result of geographic isolation
23
Q
Alveolus
A
A microscopic air sac in the lungs where gas exchange occurs
24
Q
Amino acid
A
A monomer of proteins
25
Ammonification
The process in which nitrogen compounds from dead organisms or waste material are turned into ammonium compounds by saprobionts
26
Anomalous result
A measurement that falls outside the range of values you'd expect or any pattern you already have
27
Antibiotic
A medicine that is designed to kill or inhibit the growth of bacteria (or sometimes fungi)
28
Antibiotic resistance
When bacteria are able to survive in the presence of antibiotics
29
Antibody
A protein produced by B-cells in response to the presence of a pathogen
30
Antidiuretic hormone (ADH)
A hormone that regulates the water potential of the blood by controlling the permeability of the cells of the distal convoluted tubule and the collecting duct in the kidney
31
Antigen
A molecule (usually a protein) that can trigger an immune response
32
Antigenic variation
Where pathogens change their antigen
33
Antigen-presenting cell
An immune system ell that processes and presents antigens on its surface to activate other immune system cells
34
Antimicrobial substance
A substance designed to kill microorganisms (e.g. an antibiotic, antiseptic or disinfectant)
35
Artefact (microscope)
Something you can see on a microscope slide that isn't part of the specimen you're looking at (e.g. an air bubble)
36
Arteriole
A blood vessel that branches off an artery
37
Aseptic technique
A technique used to prevent the unwanted growth or transfer of microorganisms
38
Atheroma
Fibrous plaque caused by the build up and hardening of white blood cells, lipids and connective tissue
39
ATP (adenosine triphosphate)
A molecule made up of adenine, a ribose sugar and three phosphate groups. It is the immediate source of energy in a cell
40
ATP Hydrolase
An enzyme which catalyses the hydrolysis of ATP into ADP and Pi
41
ATP-phosphocreatine (PCr) system
A system that generates ATP very quickly by phosphorylating ADP using a phosphate group from phosphocreatine
42
ATP synthase
An enzyme which catalyses the synthesis of ATP from ADP and Pi
43
Atrioventricular node (AVN)
A group of cells in the heart wall that is responsible for passing waves of electrical activity from the SAN on to the bundle of His
44
Atrioventricular valve (AV)
A valve in the heart linking the atria to the ventricles
45
Attachment protein (virus)
A protein on the surface of a virus that lets the virus cling onto a suitable host cell
46
Autonomic nervous system
A division of the peripheral nervous system that controls unconscious activities (e.g. heart rate)
47
Autoradiography
A technique that reveals the location of radioactive tracers
48
Autosomal linkage
When two genes are located on the same autosome and are inherited by the offspring together
49
Autosome
A chromosome that isn't a sex chromosome
50
Base
A nitrogen-containing molecule that forms part of a DNA molecule
51
B-cell
A type of white blood cell involved in the immune response. It produces antibodies
52
Benedict's test
A biochemical test for the presence of sugars
53
Benign tumour
A non-cancerous tumour
54
Bias
When someone intentionally, or unintentionally, favours a particular result
55
Bile salt
A type of salt produced by the liver to aid the digestion of lipids
56
Binary fission
The process by which prokaryotic cells replicate
57
Binomial system
The system used in classification for naming organisms using a two-part Latin name
58
Biodiversity
The variety of living organisms in an area
59
Biomass
The mass of living material in an organism
60
Biotic condition
A living feature of an ecosystem
61
Biuret test
A biochemical test for the presence of polypeptides and proteins
62
Bohr effect
An effect by which an increase of carbon dioxide in the blood results in a reduction of haemoglobin's affinity for oxygen
63
Bundle of His
A group of muscle fibres in the heart, responsible for conducting waves of electrical activity from the AVN to the Purkyne tissue
64
Cancer
A tumour that invades surrounding tissue
65
Capillary bed
A network of capillaries
66
Capsid
The protein coat surrounding a virus' genetic material
67
Capsule (cell)
A layer of secreted slime surrounding some prokaryotic cells
68
Cardiac cycle
An ongoing sequence of contraction and relaxation of the atria and ventricles that keeps blood continuously circulating the body
69
Cardiac output
The volume of blood pumped by the heart per minute (measured in cm^3 per minute)
70
Cardiomyocyte
A heart muscle cell
71
Cardiovascular disease
Any disease associated with the heart and blood vessels
72
Carrier
A person carrying an allele that is not expressed in their phenotype, but that can be passed on to their offspring
73
Carrier protein
A protein in a cell membrane that allows the facilitated diffusion of large molecules
74
Carrying capacity
The maximum stable population size of a species that an ecosystem can support
75
Catalyst
A chemical that speeds up a chemical reaction without being used up itself
76
Causal relationship
Where a change in one variable causes a change in the other
77
cDNA (complementary DNA)
A DNA copy of mRNA made using reverse transcriptase
78
Cell cycle
The process that all body cells from multicellular organisms use to grow and divide
79
Cell fractionation
A method that separates the organelles in a cell
80
Cell-surface membrane
The membrane found on the surface of animal cells (and just inside the cell wall of other cells). Regulates the movement of substances into and out of the cell
81
Cellular immune response
The immune response that involves T-cells and the other immune system cells they interact with (e.g. phagocytes)
82
Cellulose
A polysaccharide made of long, unbranched chains of beta glucose
83
Cell wall
The outermost cell layer found in plant, algal and fungal cells
84
Centromere
The point at which two strands of a chromosome are joined together
85
Channel protein
A protein that forms a pore in a cell membrane and allows the facilitated diffusion of charged particles
86
Chemical mediator
A chemical messenger that acts locally (i.e. on nearby cells)
87
Chemiosmosis
The process of electrons flowing down the electron transport chain and creating a proton gradient across a membrane to drive ATP synthesis
88
Chlorophyll
A photosynthetic pigment found in chloroplast. There are different types of this pigment (e.g. chlorophyll a)
89
Chloroplast
An organelle present in plant and algal cells where photosynthesis occurs
90
Choice chamber
A container with different compartments that can be used to investigate how animals respond to different environmental conditions
91
Cholesterol
A type of lipid present in cell membranes (except bacterial cell membranes)
92
Cholinergic synapse
A synapse that uses the neurotransmitter acetylcholine
93
Chromatids
One 'arm' of a double stranded chromosome
94
Chromosome
A thread like structure made up of one long DNA molecule
95
Chromosome non-disjunction
Failure of the chromosomes to separate properly during meiosis or mitosis
96
Classification
The act of arranging organisms into groups
97
Climax community
The largest and most complex community of plants and animals an ecosystem can support
98
Codominant allele
An allele whose characteristic appears together with another allele in the phenotype because neither allele is recessive
99
Codon
A base triplet (three nucleotides) in DNA or mRNA that codes for an amino acid
100
Coenzyme
A molecule that aids the function of an enzyme. They work by transferring a chemical group from one molecule to another
101
Community
All the populations of different species in a habitat
102
Compensation point
The point at which the rate of photosynthesis in a plant exactly matches its rate of respiration
103
Competitive inhibitor
A molecule that has a similar shape to a substrate and blocks an enzyme's active site
104
Complementary base pairing
Hydrogen bonding between specific pairs of bases on opposing polynucleotide strands
105
Condensation reaction
A reaction that releases a molecule of water when it links molecules together
106
Cone (eye)
A photoreceptor cell found in the eye that gives information in colour
107
Conservation
The protection and management of species and habitats (ecosystems) in a sustainable way
108
Continuous data
Data that can take any value in a range
109
Control group
A group in a study that is treated exactly the same as the experimental group, apart from the factor you're investigating
110
Control variable
A variable you keep constant throughout an experiment
111
Coordinator
Part of the nervous system (e.g. the CNS) which formulates an appropriate response to a stimulus before sending impulses to an effector
112
Coronary artery
An artery supplying the heart muscle with blood
113
Coronary heart disease
When the coronary arteries have lots of atheromas in them, which restricts blood flow to the heart
114
Correlation
A relationship between two variables
115
Co-transporter
A type of carrier protein that binds two molecules at the same time
116
Counter-current system (fish)
The system in which blood flows in one direction and water flows in the opposite direction across the gills of a fish
117
Courtship behaviour
Behaviour carried out by organisms to attract a mate of the right species
118
Crossing over
When chromatids twist around each other and bits of them swap over during meiosis
119
Cytokinesis
The division of the cytoplasm during eukaryotic cell division
120
Cytoplasm
A gel-like substance where most of the chemical reactions in a cell happen
121
Cytotoxic T-cell
A T-cell that kills abnormal or foreign cells
122
Dehydrogenase
An enzyme that transfers hydrogen and electrons from one molecule to another
123
Denatured
The point at which an enzyme no longer functions as a catalyst
124
Denitrification
The process in which nitrates in the soil are converted into nitrogen gas by denitrifying bacteria
125
Deoxyribose
The pentose sugar in DNA
126
Dependent variable
The variable you measure in an experiment
127
Depolarisation
A decrease in the potential difference across a cell's membrane, making it less negative (i.e. more positive) than the resting potential
128
Type 1 Diabetes
A condition in which blood glucose concentration can't be controlled properly because the body can't produce enough insulin
129
Type 2 Diabetes
A condition in which blood glucose concentration can't be controlled properly because the body doesn't produce enough insulin or the body's cells don't respond properly to insulin
130
Differential reproductive success
The fact that in any population, some individuals are more likely to survive and reproduce than others
131
Diffusion (simple)
Net movement of particles from an area of higher concentration to an area of lower concentration
132
Digestion
The process of breaking down food into substances that can be used by the body
133
Dihybrid inheritance
The inheritance of two characteristics, which are controlled by different genes
134
Dipeptidase
An endopeptidase enzyme that hydrolyses bonds within a protein
135
Dipeptide
A molecule formed from two amino acids
136
Diploid
When a cell contains two copies of each chromosome
137
Directional selection
Where individuals with alleles for a single extreme phenotype are more likely to survive, reproduce and pass on their alleles
138
Disaccharide
A molecule formed from two monosaccharides
139
Discrete data
Numerical data that can only take certain values in a range
140
Disruptive selection
Where individuals with alleles for phenotypes at the extreme ends of a range are more likely to survive, reproduce and pass on their alleles
141
Distribution
Where a particular species is within an area being investigated
142
DNA (deoxyribonucleic acid)
The molecule in cells that stores genetic information
143
DNA helicase
An enzyme that breaks the hydrogen bonds between two polynucleotide DNA strands during DNA replication
144
DNA polymerase
Enzyme that joins together the nucleotides on a new strand of DNA during DNA replication
145
DNA probe
A short single strand of DNA that has a complementary base sequence to part of a target gene
146
DNA sequencing
A technique used to determine the order of bases in a section of DNA
147
Dominant allele
Allele whose characteristic appears in the phenotype even when there's only one copy
148
Double-helix
Structure of a DNA molecule - two separate strands wound together in a spiral
149
Ecosystem
All the organisms living in a community plus all the non-living (abiotic) conditions in the area in which they live
150
Effector
A cell that brings about a response to a stimulus, to produce an effect
151
Electrochemical gradient
Concentration gradient of ions
152
Electron transport chain
Chain of proteins down which excited electrons flow
153
Emulsion test
A biochemical test for the presence of lipids
154
Endopeptidase
Enzyme that hydrolyses peptide bonds within a protein
155
Endoplasmic reticulum
System of membranes enclosing a fluid-filled space. Involved with lipid and protein processing
156
Endothelium
Inner lining of a blood vessel
157
Enzyme
Protein that speeds up the rate of chemical reactions
158
Enzyme-substrate complex
Intermediate formed when a substrate molecule binds to the active site of an enzyme
159
Epigenetic control (of gene expression)
Attachment or removal of chemical groups to or from DNA or histone proteins, which determines whether a gene is switched on or off
160
Epistasis
When an allele of one gene masks (blocks) the expression of the alleles of other genes
161
Eukaryote
Organism made up of a cell (or cells) containing a nucleus (e.g. animals, plants, algae and fungi)
162
Eutrophication
The process whereby nutrients build up in water, leading to the growth of large quantities of algae. This results in death of plants, and decomposition of dead plant matter causes the oxygen content of the water to fall, killing aquatic organisms
163
Evolution
The gradual change in a species over time or the change in allele frequency in a population over time
164
Exchange organ
An organ (e.g. the lungs) specialised to exchange substances
165
Exocytosis
Process by which a cell secretes substances using vesicles
166
Exon
Section of DNA within a gene that codes for amino acids
167
Exopeptidase
An enzyme that hydrolyses the peptide bonds at the end of proteins to remove single amino acids
168
Expiration
Breathing out
169
Extracellular digestion
When food is broken down (digested) outside of a cell. Saprobionts feed using extracellular digestion
170
Facilitated diffusion
Diffusion of particles through carrier proteins or channel proteins in the plasma membrane
171
FAD
Type of coenzyme involved in respiration. It transfers hydrogen from one molecule to another
172
Fast twitch muscle fibre
Muscle fibre that contracts very quickly but also gets tired quickly
173
Fertilisation
When a haploid sperm fuses with a haploid egg to generate a diploid zygote
174
Flagellum
A long, hair-like structure that rotates to move a cell
175
Fluid mosaic model
Model describing the arrangement of molecules in a cell membrane
176
Foreign antigen
An antigen not normally found in the body
177
Founder effect
Reduction in genetic diversity that occurs when just a few organisms from a population start a new colony
178
Frameshift mutation
Mutation that changes the number of bases in the DNA code, causing a shift in the base triplets that follow, so that the triplet code is read in a different way
179
Functional RNA
RNA molecules that aren't mRNA (e.g. tRNA or RNA found in ribosomes)
180
Gametes
A sex cell (e.g. sperm cell in males or egg cell in females)
181
Gas exchange
The process of taking in gases that are needed for life processes and getting rid of waste gases
182
Gas exchange surface
A boundary between the outside environment and the internal environment of an organism, over which gas exchange occurs
183
Gel electrophoresis
A technique that allows DNA fragments to be separated on a gel according to size
184
Gene
Section of DNA that codes for a protein (polypeptide) which results in a characteristic
185
Gene expression
The transcription of a gene into mRNA and translation of the mRNA into a protein
186
Gene pool
The complete range of alleles present in a population
187
Generator potential
The change in potential difference across a cell membrane due to the presence of a stimulus
188
Gene technology
Techniques that allow the study and alteration of genes and their functions
189
Gene therapy
Possible treatment option for genetic disorders and some cancers that involves altering defective genes inside cells
190
Genetic bottleneck
An event that causes a big reduction in a population and reduces genetic diversity
191
Genetic code
The sequence of base triplets (codons) in mRNA which code for specific amino acids
192
Genetic disorder
An inherited disorder caused by an abnormal gene or chromosome
193
Genetic diversity
The number of different alleles of genes in a species or population
194
Genetic drift
Process whereby an allele becomes more common in a population due to chance
195
Genetic fingerprint
A DNA gel that shows the number of times repetitive, non-coding base sequences are repeated at different loci in an individual
196
Genetic pedigree diagram
A diagram that shows how an inherited trait (characteristic) runs in a group of related individuals
197
Genome
All the genetic material in an organism (or cell)
198
Genotype
The genetic constitution of an organism (the different alleles an organism has)
199
Geographical isolation
When a physical barrier (e.g. a flood) divides a population of a species, causing some individuals to become separated from a main population
200
Germ line therapy
Gene therapy that involves altering the alleles in sex cells
201
Gill
The respiratory organ in a fish
202
Gill filament
A thin plate in a fish's gill
203
Glomerular filtrate
The fluid present in the nephrons of the kidney, following ultrafiltration of the blood at the Bowman's capsule
204
Glomerulus
A bundle of capillaries looped inside the Bowman's capsule of a nephron. Where ultrafiltration takes place
205
Glucagon
A hormone secreted by the pancreas that has an important role in raising blood glucose concentration
206
Glucogenesis
The conversion of glycerol or amino acids to glucose, activated by glucagon
207
Glycogen
A polysaccharide made from a long, very branched chain of alpha glucose
208
Glycogenesis
The conversion of glucose to glycogen, activated by insulin
209
Glycogenolysis
The conversion of glycogen to glucose, activated by glucagon
210
Glycolipid
A lipid that has a carbohydrate attached
211
Glycolysis
The first stage of aerobic respiration, glucose is converted into pyruvate
212
Glycoprotein
A protein that has a carbohydrate attached
213
Glycosidic bond
A bond formed between monosaccharides
214
Golgi apparatus
A group of fluid-filled flattened sacs. Involved with processing and packaging lipids and proteins, making lysosomes
215
Golgi vesicle
A small, fluid-filled sac produced by the Golgi apparatus, which stores and transports lipids and proteins
216
Granum
A structure in chloroplasts formed from the stacking of thylakoid membranes
217
Gravitropism (geotropism)
Growth of a plant in response to gravity
218
Gross primary production (GPP)
Total amount of chemical energy converted from light energy by plants in a given area
219
Guard cell
A cell that controls the opening and closing of stomata
220
Habitat
The place where an organism lives within an ecosystem
221
Haemoglobin
An oxygen-carrying protein found in red blood cells
222
Haploid
When a cell contains one copy of each chromosome
223
Hardy-Weinberg principle
A mathematical model that predicts that the frequency of alleles in a population won't change from one generation to the next provided that certain conditions are met
224
Helper T-cell
A T-cell that releases chemical signals to activate other immune system cells
225
Herd immunity
Where unvaccinated people are protected because the occurrence of the disease is reduced by the number of people who are vaccinated
226
Hereditary mutation
A mutation that's inherited from your parents
227
Heterozygous
When an organism carries two different alleles at the same locus
228
Histone
A protein that DNA wraps around to form chromatin, which makes up chromosomes
229
HIV (human immunodeficiency virus)
A virus that affects the human immune system
230
Homeostasis
The maintenance of a stable internal environment
231
Homologous pair
A pair of matching chromosomes, each chromosome contains the same genes but could have different alleles
232
Homozygous
When an organism carries two copies of the same allele at the same locus
233
Host cell
A cell inside which a virus replicates or a cell that is used to carry recombinant DNA
234
Humoral immune response
The immune response that involves B-cells, clonal selection and the production of antibodies
235
Hydrolysis
A chemical reaction that uses a water molecule when it breaks bonds between molecules
236
Hydrophilic
Attracts water
237
Hydrophobic
Repels water
238
Hydrostatic pressure
The pressure exerted by a liquid
239
Hyperpolarisation
An increase in the potential difference across a cell's membrane, making it more negative than the resting potential
240
Hypothalamus
A part of the brain that controls body temperature and monitors the water potential of the blood
241
Immunity
The ability to respond quickly to an infection
242
Immunological comparison
Using antibodies to determine how similar proteins are
243
Independent segregation
The random division of maternal and paternal chromosomes into daughter cells during meiosis
244
Independent variable
The variable you change in an experiment
245
Index of diversity
A measure of biodiversity that takes into account the number of species present in a community and the abundance of each species
246
Indoleacetic acid (IAA)
An auxin produced in the tips of shoots and roots in flowering plants
247
Inspiration
Breathing in
248
Inorganic ion
An ion that doesn't usually contain carbon
249
Insulin
A hormone secreted by the pancreas that has an important role in lowering blood glucose concentration
250
Interphase
A period of the cell cycle in which the cell grows and the DNA is replicated
251
Interspecific competition
Competition between organisms of different species for the same resources
252
Intron
A section of DNA within a gene that does not code for amino acids
253
In vitro cloning
When gene copies are made outside of a living organism using PCR
254
In vivo cloning
When gene copies are made within a living organism as it grows and divides
255
Iodine test
A biochemical test for the presence of starch
256
iPS (induced pluripotent stem) cell
A type of pluripotent stem cell made in the lab by reprogramming a specialised adult body cell to express certain transcription factors
257
Kinesis (kinetic response)
Non-directional movement in response to a stimulus
258
Krebs cycle
The third stage of aerobic respiration. It is a series of oxidation-reduction reactions that produces reduced coenzymes and ATP
259
Lamella (chloroplasts)
A thin, flat piece of thylakoid membrane found in chloroplasts
260
Lamella (fish)
A tiny structure found on the gill filament in a fish
261
Leaching
The process in which water-soluble compounds in the soil are washed away (e.g. by rain)
262
Ligase
An enzyme that joins together the sticky ends of DNA fragments
263
Light-dependent reaction
The first stage of photosynthesis. Light energy is absorbed by photosynthetic pigments and converted to ATP and reduced NADP
264
Light-independent reaction (Calvin cycle)
The second stage of photosynthesis. ATP and reduced NADP are used to make glucose from carbon dioxide
265
Limiting factor
A variable that can slow down the rate of a reaction
266
Link reaction
The second stage of aerobic respiration where pyruvate is converted into acetyl coenzyme A
267
Lipase
An enzyme that catalyses the hydrolysis of lipids
268
Loading of oxygen (onto haemoglobin)
The action of an oxygen molecule binding with a haemoglobin molecule
269
Locus
The position on a chromosome where a particular allele is found
270
Loop of Henle
Part of the kidney nephron responsible for establishing the water potential gradient, which allows water to be reabsorbed by the kidney
271
Lymphatic system
A network of tubes which transports excess tissue fluid back into the circulatory system
272
Lysosome
A round organelle that contains digestive enzymes called lysozymes
273
Magnification
How much bigger an image from a microscope is compared to the specimen
274
Malignant tumour (cancer)
A tumour that invades and destroys surrounding tissues
275
Margin of error
The range in which the true value of a measurement lies
276
Marker gene
A gene that can be inserted into transformed cells in order to identify them
277
Mark-release-recapture
A method used to estimate the population size of organisms
278
Mass transport system
A system (e.g. the circulatory system) that carries substances to and from individual cells
279
Medulla (oblongata)
A part of the brain that controls heart rate
280
Meiosis
A type of cell division where a parent cell divides to create four genetically different haploid cells
281
Memory cell
A white blood cell that remains in the body and remembers how to respond to infections
282
Meristem
A growing region of a plant (e.g. the shoots and roots) which contain totipotent stem cells
283
Mesophyll cell
A type of plant cell present in a leaf and the main gas exchange surface in a plant
284
Metabolic rate
The rate at which energy is used by an organism
285
Methylation
Attachment of a methyl group to something (e.g. DNA)
286
