Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > A Level - Keywords > Flashcards

A Level - Keywords Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

cell signalling

A

how cells communicate with each other. Done with nervous impulses or hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Stimulus

A

change in an environment that causes a response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Response

A

change in behaviour/physiology as a results of a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ectotherm

A

an organism that relies on external sources of heat to regulate body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Endotherm

A

an organism that can control the generation or loss of heat to maintain its body temperature using physiological or behavioural responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Homeostasis

A

the maintenance of the internal environment in a constant state despite external changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Negative feedback

A

a process that brings about a reversal of any change in conditions in order to return to
an optimum steady state. Essential for homeostasis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Positive feedback

A

a process that increases any change detected by the receptors. Does not lead to homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Generator potential

A

Small depolarisation caused by sodium ions entering the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Resting potential

A

when neurone is at rest (no stimulus), -70mV.

sodium/potassium ion pumps [3 out/2 in], K+ leakage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Depolarisation

A

loss of polarisation due to entry of Na+ entering the cell. Potential difference across membrane becomes less negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Threshold potential

A

creates and action potential there is a big enough stimulus for enough Na+ enter the cell for the potential difference to exceed -50mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Action potential

A

Membrane is depolarised to +40mV. All or nothing response. Transmitted along the axon membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Repolarisation

A

membrane becomes polarised again due to loss of K+ through v-g channels. Potential difference across membrane becomes more negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hyperpolarisation

A

too many K+ diffuse out - potential difference under -70mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Refractory period

A

following an action potential, there is a need to redistribute sodium and potassium ions and restore resting potential. During this time another impulse cannot be generated. Ensures impulses separated, determines maximum frequency of impulse transmission, ensure impulse passes in one direction only along axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Local currents

A

movements of ions along the neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Saltatory conduction

A

how the action potential ‘jumps’ from one Node of Ranvier to the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Endocrine glands

A

produce and secrete hormones directly into the blood - they have no ducts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Exocrine glands

A

do not produce hormones - they secrete molecules into a duct which carries them to where they are needed .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hormone

A

molecules released by endocrine glands into the blood and act as messengers carrying a signal from the endrocrine gland to the target tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Target cells/tissue

A

possess specific receptors on their cell surface membrane which is complementary in shape to a hormone molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Neurotransmitter

A

a chemical that diffuses across the synaptic cleft to transmit a signal to the post- synaptic membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cholinergic synapse

A

use acetylcholine as the neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Acetylcholinesterase

A

enzyme that breaks down acetylcholine in the synaptic cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Summation

A

how several small potential changes across the axon/dendron membrane can combine to produce one larger change in potential difference across the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

First messenger

A

hormones that transmits a signal around the body in the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Second messenger

A

cAMP which transmits a signal inside the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Hepatocytes

A

liver cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Diabetes mellitus

A

a disease in which you can’t control your blood glucose concentrations effectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Hyperglycemia

A

Blood glucose levels are too high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Hypoglycemia

A

blood glucose levels are too low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Glycogenolysis

A

glycogen being converted into glucose. Occurs in the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Gluconeogenesis

A

fatty acids/amino acids –> glucose. Occurs in the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Glycogenesis

A

glucose being converted into glycogen. Occurs in the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Myogenic

A

muscle can initiate its own contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Excretion

A

removal of the unwanted / toxic / waste, products of metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Deamination

A 
Removes the amine group from amino acid - produces a keto acid (can be respired) and also
produces ammonia (soluble and highly toxic). Occurs in the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Ornithine cycle

A

ammonia is converted into urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Ultrafiltration

A

filtration at molecular level in glomerulus by the basement membrane - smaller molecules (urea, water, glucose, amino acids, ions) are filtered out of the blood into the lumen of the Bowman’s capsule.

41
Q

Selective reabsorption

A

useful substances are reabsorbed from the nephron (most happens in the PCT) into the blood e.g. glucose. Excretory substances remain in the nephron. E.g. urea

42
Q

Hairpin countercurrent multiplier

A

arrangement of a tubule in a sharp U shape so one part passes close to another with the fluid in opposite directions. This allows exchange
between the contents and can be used to create a high concentration of solutes.

43
Q

Osmoregulation

A

control and regulation of water potential of the blood and bodily fluids. Controlled by the kidney (particularly the collecting duct)

44
Q

Osmoreceptors

A

monitor changes in water potential of the blood. Found in the hypothalamus.

45
Q

Neurosecretory cells

A

make ADH in the hypothalamus in response to low water potential in the blood. This collects in the terminal bulb found in the posterior pituitary gland where ADHis released.

46
Q

ADH

A

anti diuretic hormone. Increases reabsorption of water.

47
Q

Dialysis

A

use of a partially permeable membrane to filter the blood

48
Q

Clones

A

genetically identical to their one parent. They are formed by as exual reproduction (mitosis in eukaryotes; binary fission in prokaryotes)

49
Q

Vegetative propagation

A

the production of structures in an organism that can grow into new organisms, genetically identical to the parent (clones).

50
Q

Biotechnology

A

the industrial use of living organisms to produce food, drugs or other products

51
Q

Asepsis

A

absence of unwanted microbes

52
Q

Aseptic technique

A

any measure to avoid unwanted microbes contaminating culture/products

53
Q

Primary metabolites

A

Produced during normal (log) growth phase. Essential for normal cell growth/reproduction. Match growth in population (i.e. same pattern as growth curve)

54
Q

Secondary metabolite

A

Produced after/not produced during the (log / rapid / main) growth phase. Not essential for normal, cell growth

55
Q

Immobilised enzymes

A

enzymes attached to an insoluble material in order to keep them separate from the reaction mixture.

56
Q

Recombinant DNA

A

DNA from two different sources which is combined / joined

57
Q

Restriction enzyme

A

cuts DNA with sticky ends. Specific restriction site.

58
Q

Gene therapy

A

treating genetic disorders using genetic technology

59
Q

Xenotransplant

A

Transplant of tissues/organs between animals of different species.

60
Q

Genome

A

all the genetic information in an organism

61
Q

Ecosystem

A

any group of living organisms and non-living things occurring together and the interrelationships between them

62
Q

Habitat

A

the place where an organism lives

63
Q

Population

A

all of the organisms of one species who live in the same place, at the same time and breed together

64
Q

Community

A

all the populations of different species who live in the same place at the same time and can interact with each other

65
Q

Niche

A

the role of an organism in the ecosystem

66
Q

Biotic factors

A

living organisms in an ecosystem that can affect each other

67
Q

Abiotic factors

A

non-living things in an ecosystem that can affect the living organisms

68
Q

Trophic level

A

stage in a food chain

69
Q

Producers

A

start of food chains (usually plants), converts energy from sunlight into chemical energy (glucose) in photosynthesis. Supply the chemical energy to the rest of the food chain.

70
Q

Primary consumers

A

get their energy by feeding on producers

71
Q

Secondary consumers

A

get their energy by feeding on primary consumers

72
Q

Decomposers

A

feed on waste and dead organisms

73
Q

Biomass

A

the dry mass of living material in an organism

74
Q

Gross primary productivity

A

rate at which plants convert light energy into chemical energy in photosynthesis. e.g. Units: MJ m-2 yr-1

75
Q

Net primary productivity (NPP)

A

rate of production of new biomass available for heterotrophic consumption and therefore the amount of energy available to them. e.g.
Units: kg ha-1 yr-1
NPP = gross primary productivity - respiration (R)

76
Q

Succession

A

is a natural directional change in species composition in an area over a period of time. Happens in a series of recognisable stages. Where one community (sere) changes the
conditions for the next e.g. depth of soil. Results in a climax community e.g. woodland

77
Q

Primary succession

A

is a natural directional change in species composition in an area over a period of time. Happens in a series of recognisable stages. Where one community (sere) changes the conditions for the next e.g. depth of soil. Begins with bare ground/rock, which a pioneer species e.g. algae/moss colonises first. Results in a climax community e.g. woodland

78
Q

Climax community

A

final stage in succession in which the community is in equilibrium with environment.

79
Q

Deflected succession

A

When something e.g. grazing/burning/trampling of plants prevents succession and therefore the establishment of the next community

80
Q

Secondary succession

A

When succession takes place on a previously colonised, but damaged habitat. It does not start from bare ground.

81
Q

Decomposers

A

microorganisms which break down dead and waste organic material e.g. bacteria, fungi

82
Q

Nitrogen fixation

A

converting nitrogen into compounds useable for plants (nitrates/ammonium ions)

83
Q

Rhizobium

A

Nitrogen fixing bacteria. Convert Found in root nodules of legumes plants or free in the soil. Convert nitrogen gas into ammonium ions.

84
Q

Nitrification

A

absorbing ammonium ions. Done by nitrifying bacteria

85
Q

Nitrosomanas

A

nitrifying bacteria. Convert ammonium ions into nitrites

86
Q

Nitrobacter

A

nitrifying bacteria. Convert nitrites into nitrates

87
Q

Denitrification

A

Done by denitrifying bacteria. Remove nitrates from the soil by converting nitrates to nitrogen gas. Done in anaerobic conditions.

88
Q

Carrying capacity

A

the maximum number of population supported by a particular habitat, determined by limiting factor

89
Q

Intraspecific competition

A

competition for resources between members of the same species

90
Q

Interspecific competition

A

competition for resources between members of two or more different species

91
Q

Biological resource

A

they are living and timber is of use to humans

92
Q

Sustainable production

A

harvesting in amounts which leave sufficient organisms to grow and replenish what has been harvested. It can be carried on indefinitely via replanting,
coppicing etc.

93
Q

Coppicing

A

trees cut close to ground/down stumps and several new growths form. Wood used for fire wood, furniture.

94
Q

Standards

A

Trees left uncoppiced in a coppiced woodland. Can be used for large timber e.g. planks when needed. These have higher value. Increases number of habitats within the coppiced woodland

95
Q

Pollarding

A

trees cut close to start of branches and several new growths form.

96
Q

Conservation

A

maintaining biodiversity between species, genetic diversity within species and a variety of habitats and ecosystems.

97
Q

Preservation

A

protecting land which is unused by humans to maintain natural biodiversity.

98
Q

Dynamic conservation

A

preservation of organisms or environments that are at risk from human activity. This requires management and the creation of new habitats, which may need may
need reclamation of land.

Biology (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions