Key Definitions F215

HideShow resource information
a length of DNA that codes for one or more polypeptides eg, enzymes, electron carriers, structural proteins like keratin
1 of 220
the specific place a gene occupies on a chromosome
2 of 220
Genetic code
the set of rules used to translate info in genetic material to produce proteins, 4 charac: triplet code, degenerate code, some = no AA (stop codons), widespread but not universal
3 of 220
first stage of protein synthesis, the creation of mRNA copy of the DNA coding strand
4 of 220
second stage of protein synthesis, the assembly of polypeptides at ribosomes
5 of 220
changes in the amount of or arrangement of the genetic material in a cell
6 of 220
Chromosome mutation
involves changes to parts of or whole chromosomes
7 of 220
DNA mutations
changes to genes due to changes in nucleotide base sequences
8 of 220
Point mutations
where one base pair replaces another, also called substitution
9 of 220
Insertion/deletion mutations
where one or more base pairs are inserted or deleted from a length of DNA, causes a frameshift where every AA after that is different
10 of 220
The lac operon
a functional unit of genes in the genome of prokaryotic cells, made up of structural genes and control sites
11 of 220
Homeobox genes
control the development of the body plan of an organism, including the polarity and positioning of the organs ie basic structure and orientation by switching genes on/off at appropriate times
12 of 220
Hox clusters
a group of homeobox genes
13 of 220
Homeobox sequence
the sequence of 180 base pairs in a homeobox gene
14 of 220
programmed cell death, a series of biochemical events that lead to a tidy and orderly cell death
15 of 220
Cell necrosis
an untidy and damaging cell death that occurs after trauma and releases hydrolytic enzymes
16 of 220
a reduction division where four haploid daughter cells are produced for reproduction
17 of 220
Homologous chromosomes
the two chromosomes of similar length found in all diploid cells, each member has genes at the same loci and each pair has one maternal and one paternal chromosome
18 of 220
one pair of homologous chromosomes
19 of 220
the points where two non-sister chromatids exchange genetic material during crossover as they wrap around each other
20 of 220
Crossing over
where lengths of DNA are swapped from one chromatid to another at chiasmata, occurs during prophase 1
21 of 220
alternative form of a gene, found at the same postion on homologous chromosomes
22 of 220
the genetic make up, combo of alleles, of an organism
23 of 220
two identical alleles for a particular gene
24 of 220
two different alleles for a particular gene
25 of 220
the characteristics expressed in the organism that are observable, determined by both the genes and the environment
26 of 220
allele is if it is always expressed in the phenotype even if a different allele is present, the charac masks another charac
27 of 220
allele is if only expressed in the phenotype if another identical allele is present or if no dominant allele is present, otherwise this charac is masked by another charac
28 of 220
where both alleles contribute to the phenotype of a heterozygote
29 of 220
where two or more genes are located on the same chromosome, linked alleles are normally inherited together, reduces the number of phenotypes
30 of 220
Sex linkage
a charac is sex-linked if the gene that codes for it is found on one of the sex chromosomes, a certain charac will occur more often in one gender than the other
31 of 220
the interaction of different gene loci so that one gene locus masks/suppresses the expression of another gene locus
32 of 220
Recessive epistasis
where the presence of a recessive allele may prevent the expression of another allele at a second locus, 9:3:4
33 of 220
Dominant epistasis
where a dominant allele at one gene locus masks the expression of the alleles at a second gene locus, 12:3:1/13:3
34 of 220
Complementary epistasis
where two genes interact and compliment each other, both working together to produce a phenotype, 9:7
35 of 220
Chi-squared test
a statistical test used to determine whether the observed results differ significantly from the expected results
36 of 220
Discontinuous variation
describes qualitative differences between phenotypes that fall into clearly distinguishable categories, no intermediates eg gender, blood groups
37 of 220
Continuous variation
describes quantitative differences between phenotypes, there are no distinct categories but a full range between two extremes, eg height
38 of 220
Hardy-Weinberg principle
used to calculate allele frequencies in a popn, p + q = 1, p^2 + 2pq + q^2 = 1
39 of 220
Selection pressure
an environmental factor that confers greater chances of survival to reproductive age on some members of the popn
40 of 220
Stabilising selection
where there is no evolutionary change, alleles of the extremes don't change in freq, mean doesn't change
41 of 220
Directional selection
where the environ changes and so does the selection pressure, leads to evolutionary change as now certain individuals = better adapted etc
42 of 220
Genetic drift
changes in allele frequencies (by chance!), causes large changes in small popns
43 of 220
3 isolating mechanisms that cause reproductive isolation
1) ecological/geographic, 2) seasonal/temporal, 3) reproductive
44 of 220
The biological species concept
a species is a group of similar organisms that are able to interbreed to produce fertile offspring
45 of 220
The phylogenetic species concept
a group of organisms that have similar morphology, physiology, embryology and behaviour and occupy the same ecological niche
46 of 220
Natural selection
a mechanism for evolution, organisms best adapted survive and reproduce, passing on favorable alleles, environ does the selecting
47 of 220
Artificial selection
where humans do the selecting by selecting useful characteristics in animals/plants and breeding them together, must continue over several generations
48 of 220
A clone
describes genes, cells or whole organisms that carry identical genetic material because they are derived from the same original DNA
49 of 220
Reproductive cloning
the process of artificially cloning whole organisms
50 of 220
Non-reproductive cloning
the process of making many identical copies without the intention of producing a new organism
51 of 220
Vegetative propagation
refers to the production of structures in an organism that can grow into new individual organisms eg root suckers, runners, bulbs
52 of 220
Tissue culture
the separation of cells of any tissue type and their growth in/on a nutrient medium
53 of 220
involves the exploitation of living organisms/biological processes to improve agriculture, animal husbandry, food science, medicine and industry
54 of 220
a growth of microorganisms, single or mixture of species
55 of 220
Closed culture
refers to the growth of microorganisms in an environment where all the conditions are fixed and contained, no new materials are added and no waste products removed
56 of 220
Lag phase
organisms are adjusting to surrounding conditions, taking in water, activating genes etc
57 of 220
Log phase
popn size doubles each generation as every individual has enough space and nutrients to reproduce
58 of 220
Stationary phase
DR = reproduction rate as nutrients and space falls and waste builds up
59 of 220
Decline/death phase
DR exceeds reproduction rate as waste builds, nutrient exhaustion, eventually all organisms will die in a closed system
60 of 220
the culturing of MOs both anaerobically and aerobically in fermentation tanks
61 of 220
Primary metabolites`
substances produced by an organism as part of its normal growth, these include AAs, proteins, enzymes, nucleic acids, ethanol and lactate, matches growth curve
62 of 220
Secondary metabolites
substances produced by an organism that aren't part of its normal growth, usually after the main growth period and so doesn't match the growth curve, eg antibiotics, only small numbers of MOs produce these
63 of 220
Batch culture
where a starter popn of MOs is supplied with a fixed amount of nutrients and allowed to grow. At the end, the products are extracted and tank is emptied. Eg, penicillin
64 of 220
Continuous culture
where nutrients are added to the tank and products removed at regular intervals, maintained at the log phase, eg insulin
65 of 220
the absence of unwanted microorganisms
66 of 220
Aseptic technique
any measure taken at any point in a biotechnological process to ensure that unwanted MOs do not contaminate the culture or the products from isolation of the initial culture, through scaling up, fermentation and product harvesting
67 of 220
any unwanted microorganism
68 of 220
Downstream processing
the processes involved in the separation and purification of any product of large-scale fermentations
69 of 220
Immobilisation of enzymes
refers to any technique where enzyme molecules are held, separated from the reaction mixture and so do not mix freely but the substrates can still bind and the products just go back into the mixture
70 of 220
enzyme molecules mixed with the immobilising support and bind to it
71 of 220
Covalent bonding
enzymes are covalently bonded to a support often linking enzymes together with an insoluble material using a cross linking agent
72 of 220
enzymes may be trapped in a gel bead and in their natural state
73 of 220
Membrane separation
enzymes physically separated from the substrate mixture by a partially permeable membrane
74 of 220
all the genetic information inside a cell or organism
75 of 220
the study of the whole set of genetic information in the form of DNA base sequences that occur in the cells of organisms of a particular species
76 of 220
Recombinant DNA
DNA from one organism that contains a gene from another organism or species
77 of 220
used to separate DNA fragments based on their size
78 of 220
DNA probe
a short single-stranded piece of DNA that is complementary to a section of the DNA being investigated, used to identify genes with a specific nucleotide sequence
79 of 220
the complementary base pairing binding between the DNA probe and the DNA fragment
80 of 220
The polymerase chain reaction (PCR)
artificial DNA replication done to amplify the amount of genetic material
81 of 220
short, single-stranded sequences of DNA needed in sequencing and PC reactions to bind to a section of DNA so that DNA polymerase will bind
82 of 220
Genetic engineering
a number of different processes for obtaining a specific gene and placing that gene in another organism, recipient organism = transgenic
83 of 220
short, circular pieces of DNA
84 of 220
Restriction enzymes
cut through DNA at specific points, they are specific to which base sequence they cut, sequence = restriction site
85 of 220
Sticky end
formed when DNA is cut using a restriction enzyme, short run of unpaired, exposed bases seen at the end of the cut section, complementary sticky ends can anneal
86 of 220
DNA ligase
an enzyme used to catalyse a condensation reaction which joins the sugar-phosphate backbones
87 of 220
Recombinant plasmid
a plasmid that has taken up the desired gene
88 of 220
Heat shock
where the temperature of the culture is lowered to around freezing then quickly raised to 40 degrees
89 of 220
Transformed bacteria
bacteria that have taken up the recombinant plasmid
90 of 220
Bacterial conjugation
where genetic material is exchanged between bacteria
91 of 220
Replica plating
the process of growing bacteria on an agar plate, then transferring a replica of that growth to other plates
92 of 220
the transplant of organs from one species to another
93 of 220
Gene therapy
treating genetic disorders by inserting new genes
94 of 220
Somatic gene therapy
adding genes into a body cell so that the cell can produce a specific protein (augmentation), can kill specific cells too
95 of 220
Germline cell therapy
treating a fertilised egg so that all cells in that organism possess the required gene
96 of 220
all the interactions between the living and non-living components in a habitat
97 of 220
place where an organism lives
98 of 220
all of the organisms of one species that live in the same place at the same time and can breed together
99 of 220
all the populations of different species that live in the same place at the same time and can interact with eachother
100 of 220
the role each species plays in an ecosystem
101 of 220
autotrophs that convert energy from the environment into chemical energy for other organisms
102 of 220
organisms that feed on other organisms, they digest the complex organic molecules made by autotrophs, primary consumers eat plants and secondary eat primary etc
103 of 220
organisms that feed on waste or on dead organic matter, bacteria fungi and some animals
104 of 220
Trophic level
level at which an organism feeds in a food chain
105 of 220
Pyramid of numbers
where the area of each bar is proportional to the number of individuals
106 of 220
Pyramid of biomass
where the area of the bars is proportional to the dry mass of all the organisms at that trophic level
107 of 220
Pyramid of energy
working out how much heat energy is released per gram
108 of 220
the rate at which energy passes through each trophic level in a food chain
109 of 220
Gross primary productivity
the rate at which plants convert light energy into chemical energy
110 of 220
Net primary productivity
the remaining energy after respiratory heat loss has been taken off
111 of 220
a directional change in a community of organisms over time
112 of 220
Primary succession
development of a community from bare ground
113 of 220
Pioneer community
the first species that begin to live on the bare rock, they are hardy and can withstand harsh conditions, small and few present, produces soil
114 of 220
Climax community
the last stage of succession, the final community of well-adapted competitors are present, the community is stable and consists of larger plants
115 of 220
Secondary succession
takes place on previously colonised but disturbed or damaged habitat
116 of 220
a square frame that defines the sample area, often 1 m square, placed over a random site and examined closely to identify plants inside
117 of 220
Point quadrat
placing a point frame in a quadrat and counting the species that touch each point
118 of 220
presence/absence of species
119 of 220
number of individuals
120 of 220
Pilot studies
used to work out the number of quadrats needed and how big they should be
121 of 220
a line taken across a habitat, can be tape or rope
122 of 220
Line transect
continuous = observations made along the transect and every species touching it is recorded and abundance is estimated, interrupted = at regular intervals which species touch the tape is recorded and abundance estimated
123 of 220
Belt transect
continuous = quadrat is placed next to line and moved along the line studying each, interrupted = where a quadrat is placed next to the line at regular intervals and studied
124 of 220
an organism that feeds on decaying organic matter
125 of 220
Nitrogen fixation
the process of converting nitrogen gas into ammonium ions, can occur when lightning strikes, through the haber process or nitrogen-fixing bacteria (eg. Rhizobium) they use nitrogen reductase to reduce nitrogen gas to ammonium ions in anaerobic cond
126 of 220
the process of chemoautotrophic bacteria obtaining energy by oxidising ammonium ions to nitrites (Nitrosomonas bacteria) or by oxidising nitrites to nitrates (Nitrobacter bacteria)
127 of 220
the process of bacteria converting nitrates back into nitrogen gas, they use the nitrates as a source of oxygen for respiration and produce nitrogen gas & nitrous oxide (anaerobic)
128 of 220
Carrying capacity
the maximum population size that can be maintained over a period of time in a particular habitat
129 of 220
Limiting factor
one component of the ecosystem that limits the growth and final size of the population eg availability of resources, number of predators, disease, behaviour, natural disasters, climate and weather
130 of 220
happens when resources like food or water are not present in adequate amounts to satisfy the needs of all the individuals who depend on those resources
131 of 220
Intraspecific competition
occurs between individuals of the same species, as factors such as food supplies become limiting the individuals have to compete for them, keeps the population relatively stable
132 of 220
Interspecific competition
occurs between individuals of different species, can affect both the population size of a species and the distribution of species in an ecosystem+
133 of 220
Competitive exclusion principle
the idea if two species have exactly the same niche, one would be out-competed by the other and would become extinct/die out
134 of 220
involves cutting a tree trunk close to the ground to encourage new root growth, once cut several new shoots grow and make stems of a small diameter, used for fencing, firewood or furniture
135 of 220
involves cutting a tree trunk higher up which can be done to prevent deer from eating the emerging shoots
136 of 220
Rotational coppicing
where woodland managers divide a wood into sections and cut one each year until they've all been cut, once back to the beginning the new stems have already matured
137 of 220
trees that are left to grow larger without being coppiced, eventually harvested to supply larger pieces of timber, increases biodiversity and prevents succession, protects soil
138 of 220
Selective cutting
involves removing only the largest, most valuable trees so the habitat is broadly unaffected
139 of 220
involves the maintenance of biodiversity including diversity between species & genetic diversity within species and maintenance of a variety of habitats and ecosystems
140 of 220
maintaining or protecting an area in its current state, best applied to areas that have not yet been affected by humans
141 of 220
means the preying on one organism by another
142 of 220
Abiotic stress
the negative impact of non-living factors on the living organisms in a specific environment
143 of 220
A tropism
a directional growth response/movement where the direction is determined by the direction of the external stimulus
144 of 220
the directional growth response to light, shoots grow towards light
145 of 220
the directional growth response to gravity, roots grow towards the pull of gravity, shoots grow away from it
146 of 220
the response to certain chemicals, the pollen tube grow down the style towards the ovum during reproduction
147 of 220
the directional growth response to touch, shoots of climbing plants like ivy, wind around other plants or solid structures and gain support
148 of 220
Plant hormones ("plant growth regulators")
chemical messengers that can be transported away from their site of manufacture (cells in a variety of tissues in the plant) to act in other parts of the plant, they coordinate plant responses to environmental stimuli
149 of 220
where two or more hormones amplify each others effects
150 of 220
where two or more hormones can cancel out each others effects
151 of 220
promote cell elongation, inhibit growth of side shoots and inhibit leaf abscission
152 of 220
promote cell division
153 of 220
promote seed germination and growth of stems
154 of 220
Abscisic acid
inhibits seed germination and growth, causes stomatal closure when the plant is stressed by low water availability
155 of 220
promotes fruit ripening
156 of 220
places where there are groups of immature cells that are still capable of dividing
157 of 220
Apical meristems
are located at the tips/apices of roots and shoots & are responsible for the roots and shoots getting longer
158 of 220
Lateral bud meristems
are found in the buds, these could give rise to side shoots
159 of 220
Lateral meristems
are found in a cylinder near the outside of roots and shoots & are responsible for the roots and shoots getting wider
160 of 220
Intercalary meristems
in some plants only, located between the nodes where the leaves and buds branch off the stem, growth between nodes is responsible for the shoot getting longer
161 of 220
leaves ageing - turning brown and dying
162 of 220
the shedding of leaves after senescence
163 of 220
Abscission zone
a region of cells at the end of a leaf stalk that responds to a number of plant hormones
164 of 220
Apical dominance
where the growing apical bud at the tip of the shoot inhibits growth of the lateral buds further down the shoot
165 of 220
The cerebrum
the largest and most recognisable part of the brain, responsible for the elements of the nervous system that are associated with being human including thought, imagination and reasoning, divided into two hemispheres connected via the corpus callosum
166 of 220
Sensory areas
receive impulses indirectly from the receptors
167 of 220
Association areas
compare input with previous experiences in order to interpret what the input means and judge an appropriate response
168 of 220
Motor areas
send impulses to effectors, motor areas on left side of cerebral cortex control movements on the right side of the body and vice versa
169 of 220
The cerebellum
controls the coordination of fine movement and posture, non-conscious operation
170 of 220
The medulla oblongata
controls the action of smooth and cardiac muscle, in control of the autonomic nervous system, controls breathing movements (respiratory centre) and heart rate (cardiac centre)
171 of 220
The hypothalamus
controls most of the body's homeostatic mechanisms, regulating temperature and blood water potential, controls much of the endocrine function of the body as it regulates the pituitary gland
172 of 220
Central nervous system
consists of the brain and spinal cord, made up of grey matter and white matter
173 of 220
Peripheral nervous system
made up of the neurones that carry impulses into and out of the CNS
174 of 220
Somatic motor neurones
carry impulses from the CNS to skeletal muscles which are under voluntary control
175 of 220
Autonomic motor neurones
carry impulses from the CNS to cardiac muscle, smooth muscle in the gut wall and to glands, all unconscious/involuntary control
176 of 220
Autonomic nervous system
a series of motor neurones that coordinate the unconscious responses involved in homeostasis
177 of 220
a swelling where two neurones connect
178 of 220
Sympathetic nervous system
most active in times of stress, neurones linked at a ganglion outside spinal cord, secrete noradrenaline between synapse and effector, effects include increased HR, pupil dilation, increased ventilation rate
179 of 220
Parasympathetic nervous system
most active in times of sleep/relaxation, neurones linked at a ganglion in target tissue, secrete acetylcholine between neurone and effector, effects include decreased HR, pupil constriction, decreased ventilation rate
180 of 220
how voluntary muscles are attached to the bones of the skeleton, made of tough inelastic collagen which is continuous with the muscle and connective tissues
181 of 220
Antagonistic pairs
where two muscles work against each other, one contracting and one relaxing to allow smooth movement
182 of 220
groups of muscles working together to move bones at joints
183 of 220
The elbow joint
an example of a synovial joint, large degree of movement is required, synovial fluid acts as a lubricant which eases the movement, biceps and triceps work antagonistically in order to move the forearm at the elbow
184 of 220
Neuromuscular junction
a specialised synapse which occurs at the end of a motor neurone where it meets the muscle fibre, acetylcholine is the neurotransmitter released
185 of 220
Motor end plate
the end of a motor neurone
186 of 220
Motor unit
a cluster of muscle cells contracting
187 of 220
Gradation of response
the idea that the more motor units stimulated, the greater the force of contraction
188 of 220
Muscle twitch
a quick contraction followed by immediate relaxation
189 of 220
where two large, separate stimuli are applied close together, overlapping the response and making it more powerful
190 of 220
repeated large stimuli give a sustained and powerful contraction
191 of 220
Involuntary (smooth) muscle
innervated by neurones of the autonomic nervous system, not under conscious control, in the intestine walls/iris of the eye/walls of arteries, not striated, small bundles of actin & myosin and a single nucleus, slow contraction and fatigue
192 of 220
Cardiac muscle
atrial muscle, ventricular muscle and specialised excitatory & conductive muscle fibres, made of many individual cells connected in rows, contain intercalated discs, striated, powerful contraction with no fatigue
193 of 220
Voluntary (skeletal) muscle
leads of movement of the skeleton at joints, form fibres containing several nuclei, each fibre membrane = sarcolemma, cytoplasm = sarcoplasm, myofibrils = contractile element containing sarcomeres made of actin&myosin, striated, powerful but fatigues
194 of 220
the smallest contractile unit of a muscle, the span from one Z-line to another
195 of 220
Thin filaments
two strands made of F actin coiled around each other, made of G actin subunits, tropomyosin molecules coil around the F actin, troponin complex is attached to each tropomyosin molecule, troponin = 3 polypeptides (binding sites)
196 of 220
Thick filaments
bundles of the protein myosin, each myosin molecule consists of a tail and 2 protruding heads, each thick filament = many myosin molecules whose heads stick out from opposite ends of the filament
197 of 220
the name given to the attachment formed by a myosin head binding to a binding site on an actin filament
198 of 220
Power stroke
where ADP and P are released when the myosin head bends, pulling the thin filament along to overlap more with the thick filament
199 of 220
Creatine phosphate
in the muscle cell sarcoplasm, the phosphate group can be transferred to ADP to from ATP by the action of enzyme creatine phosphotransferase
200 of 220
The fight or flight response
the full range of coordinated responses of animals to situations of perceived danger, combined nervous and hormonal response has dramatic effects, increase activity of the sympathetic NS and release of adrenaline
201 of 220
A stressor
a stimulus that causes the stress response, causes wear and tear on the body's physical or mental resources
202 of 220
the responses of an organism to its environment which increase its chances of survival
203 of 220
Innate behaviour
any animal response that occurs without the need for learning, genetically determined, rigid and inflexible, patterns = the same in all members, unintelligent
204 of 220
involuntary responses which follow a specific pattern in response to a given stimulus
205 of 220
an orientation behaviour where the rate of movement increases when the organism is in unfavourable conditions, behaviour = non-directional
206 of 220
a directional orientation response where the direction of movement is described in relation to the stimulus which triggers the behavioural response
207 of 220
Learned behaviour
animal responses that change or adapt with experience, determined by relationship between the genetic make up of the individual and environmental influences, altered by experience, variety shown between members, basis of intelligent activity
208 of 220
where animals learn to ignore certain stimuli because repeated exposure to the stimulus results in neither a reward nor a punishment
209 of 220
involves young animals becoming associated with another organism, usually the parent, only occurs in a sensitive period
210 of 220
Classical conditioning
where animals can learn to associate a pair of events/stimuli and respond to the first in anticipation of the second, this type = passive and involuntary
211 of 220
Operant conditioning
learning through reinforcement - punishment/reward, they associate the behaviour with getting the reward or punishment so do or don't do it, active and voluntary
212 of 220
Latent (exploratory) learning
animals will explore new surroundings and retain information about their surroundings that is not of immediate use but may be essential to staying alive at some future time
213 of 220
Insight learning
highest form of learning, based on the ability to think and reason in order to solve problems or deal with situations in ways that don't resemble simple, fixed reflex responses, once solved the solution is remembered
214 of 220
within a group exists where individuals have a place in the order of importance within the group
215 of 220
Social behaviour
organisms of a particular species living together in groups with relatively defined roles for each member of the group
216 of 220
A troop
a stable group of around 10 mountain gorillas, usually has one mature dominant male (silverback), a number of adult females and their offspring
217 of 220
where one individual gorilla picks the parasites from the fur of another, occurs between all members of the group - reinforces relationships
218 of 220
a neurotransmitter and a hormone, precursor molecule in the production of adrenaline and noradrenaline, low = Parkinsons, high = schizophrenia, increases general arousal and decreases inhibition
219 of 220
one of the five genes that code for dopamine receptor molecules, dopamine can bind to each of these molecules but cause differing effects because they lead to differing cell responses
220 of 220

Other cards in this set

Card 2


the specific place a gene occupies on a chromosome



Card 3


the set of rules used to translate info in genetic material to produce proteins, 4 charac: triplet code, degenerate code, some = no AA (stop codons), widespread but not universal


Preview of the back of card 3

Card 4


first stage of protein synthesis, the creation of mRNA copy of the DNA coding strand


Preview of the back of card 4

Card 5


second stage of protein synthesis, the assembly of polypeptides at ribosomes


Preview of the back of card 5
View more cards


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Definitions resources »