Definitions

Question 1

Anticodon

Answer 1

A sequence of 3 adjacent nucleotides on a molecule of tRNA that is complementary to a particular codon on a mRNA molecule

Question 2

Cardiac Muscle

Answer 2

Type of muscle found only in the heart. Fewer striations than skeletal muscle and can contract continuously throughout life without stimulation by nerve impulses.

Question 3

Clone

Answer 3

A group of genetically identical organisms formed form a single parent as a result of asexual reproduction or by artificial means

Question 4

Dendrite

Answer 4

Extending from the cell body of a neurone -> conducts impulses towards the cell body

Question 5

Depolarisation

Answer 5

Temporary reversal of charges on the csm of a neurone that takes place when a nerve impulse is transmitted

Question 6

Diabetes

Answer 6

A metabolic disorder in which the body is unable to regulate the level of blood glucose

Question 7

DNA helicase

Answer 7

Enzyme that acts on a specific region of the DNA molecule to break the hydrogen bonds between bases causing 2 strands to separate and expose the nucleotide bases in that region

Question 8

Ectotherm

Answer 8

An organism that uses the environment to regulate its body temperature

Question 9

Gene marker

Answer 9

A section of DNA that’s used to indicate the location of a gene or other section of DNA

Question 10

Gene therapy

Answer 10

A mechanism by which genetic diseases may be cured by masking the effect of the defective gene by inserting a functional gene

Question 11

Generator potential

Answer 11

Depolarisation of the membrane of a receptor cell as a result of a stimulus

Question 12

GMO

Answer 12

Organism that has had its DNA altered as a result of recombinant DNA technology

Question 13

Glucagon

Answer 13

A hormone produced by alpha cells of the islets of Langerhan the pancreas that increases blood glucose levels by initiating the breakdown of glycogen to glucose

Question 14

Gluconeogensis

Answer 14

The conversion of non-carbohydrate molecules to glucose

Question 15

Glycogenesis

Answer 15

The conversion of glucose to glycogen

Question 16

Hypothalamus

Answer 16

A region of the brain adjoining the pituitary gland that acts as the control centre for the autonomic nervous system and regulates body temperature and fluid balance

Question 17

Insulin

Answer 17

A hormone produced by beta cells of the islets of Langerhans in the pancreas, which decreases blood glucose levels by increasing the rate of conversion of glucose to glycogen

Question 18

Ligament

Answer 18

A tough fibrous connective tissue, rich in collagen that joins bone to bone

Question 19

Motor neurone

Answer 19

Neurone that transmits action potential from the CNS to an effector

Question 20

Mutagen

Answer 20

Any agent that induces a mutation

Question 21

Mutation

Answer 21

A change in teh sequence of bases in DNA

Question 22

Myelin

Answer 22

A fatty substance that surrounds axons and dendrites

Question 23

Negative feedback

Answer 23

A serious of changes that result in a substance being restored to its normal level

Question 24

Neurotransmitter

Answer 24

One of a number of chemicals that are involved in communication between adjacent neurones or between nerve cells and muscles.

Question 25

node of Ranvier

Answer 25

Gap in myelin sheath

Question 26

Normal distribution

Answer 26

Bell shaped curve

Question 27

Oestrous

Answer 27

The period in the oestrous cycle immediately after ovulation when the female is most fertile

Question 28

Oncogenes

Answer 28

Mutated proto-oncogenes that result in increased cell division leading to the growth of a tumour

Question 29

Pentose sugar

Answer 29

In ribose and deoxyribose

Question 30

Plasmid

Answer 30

Small circular piece of DNA found in bacterial cells

Question 31

Polygenes

Answer 31

Group of genes that are responsible for controlling a characteristic

Question 32

PCR

Answer 32

Process of making many copies of a specific sequence of DNA or part of a gene

Question 33

Positive feedback

Answer 33

Process which results in a substance that departs from its normal level becoming further from its normal

Question 34

Receptor

Answer 34

A cell adapted to detect changes in the environment

Question 35

Recognition site

Answer 35

A nucleotide sequence that is recognised by a restriction endonuclease when it attaches

Question 36

Recombinant DNA Technology

Answer 36

Processes by which genes are manipulated, altered or transferred from organism to organism

Question 37

Reflex arc

Answer 37

The nerve pathway in the body taken by an action potential that leads to a rapid, involuntary response to a stimulus

Question 38

Refractory period

Answer 38

Membrane of the axon of a neurone can't be depolarised so no new action potential can be initiated -> prevents continuous nerve impulses

Question 39

Repolarisation

Answer 39

Return to resting potential in the axon of a neurone after an action potential

Question 40

Resting potential

Answer 40

The difference in electrical charge maintained across the membrane of the axon of a neurone when not stimulated

Question 41

RNA polymerase

Answer 41

Enzyme that joins together nucleotides to form mRNA during transcription

Question 42

Restriction endonuclease

Answer 42

A group of enzymes that cut DNA molecules at a specific sequence of bases called a recognition site

Question 43

Saltatory conduction

Answer 43

Propagation of a nerve impulse along a myelinated dendron or axon in which the action potential moves by saltatory conduction through adjacent nodes of Ranvier

Question 44

Sacromere

Answer 44

A section of myofibril between two adjacent Z lines that form the basic structural unit of skeletal muscle

Question 45

Schwann cell

Answer 45

Cell around a neurone whose csm wraps around the dendron or axon to form a myelin sheath

Question 46

Sensory neurone

Answer 46

transmits an a.p. from a sensory receptor to CNS

Question 47

Skeletal muscle

Answer 47

Makes up the bulk of the body and works under conscious control -> voluntary muscle

Question 48

SAN

Answer 48

An area of the heart muscle in the right atrium that controls and coordinates the contraction of the heart

Question 49

Smooth muscle

Answer 49

Involuntary + unstriated found in the alimentary canal and the walls of blood vessels. Its contraction is not under conscious control

Question 50

Stem cells

Answer 50

Undifferentiated dividing cells

Question 51

Synapse

Answer 51

A junction between 2 neurones where they do not touch across which a NT can pass

Question 52

Tendon

Answer 52

Tough, flexible but inelastic connective tissue that joins muscle to bone

Question 53

Threshold value

Answer 53

The minimum intensity a stimulus must reach in order to trigger an action potential in a neurone

Question 54

Transducer cells

Answer 54

Cells that convert a non-electrical signal into an electrical nervous signal

Question 55

Tumour suppressor gene

Answer 55

A gene that maintains normal rates of cell division preventing the development of tumours

Question 56

Vasoconstriction

Answer 56

Narrowing of the internal diameter of blood vessles

Question 57

Vasodilation

Answer 57

Widening of the internal diameter of blood vessels

Question 58

Vector

Answer 58

A carrier e.g. a plasmid which carries DNA into a cell