GENE EXPRESSION

Question 1

GENE

Answer 1

A section of DNA which codes for a polypeptide chain

Question 2

DNA

Answer 2

Genetic material which conatins the code for the production of proteins. Made of nucleotides consisting of a phosphate, sugar and base

Question 3

HOMOLOGOUS PAIR

Answer 3

Pair of chromosomes of the same length which have genes for the same characteristics at the same loci

Question 4

AMINO ACID

Answer 4

The basic monomer of a polypeptide chain - there are 20 different naturally chromosomes types

Question 5

POLYPEPTIDE CHAIN

Answer 5

A series of amino acids bonded together

Question 6

PRIMARY PROTEIN STRUCTURE

Answer 6

The sequence of amino acids in a polypeptide chain

Question 7

TERTIARY PROTEIN STRUCTURE

Answer 7

The folding of a polypeptide chain which gives the unique shape of a protein

Question 8

PROTEIN

Answer 8

A folded polypeptide chain which has a particular function

Question 9

TRANSCRIPTION

Answer 9

The copying of a gene into a single strand of mRNA, so that the code for a polypeptide chain can be transferred to the cytoplasm

Question 10

TRANSLATION

Answer 10

The formation of a polypeptide chain using mRNA as a code

Question 11

mRNA

Answer 11

RNA which is a copy of a gene which transfers the code to make a protein to the cytoplasm

Question 12

tRNA

Answer 12

RNA which transports amino acids to the ribosome

Question 13

CODON

Answer 13

A triplet nucleotide base sequence on the mRNA which codes for one amino acid

Question 14

ANTI-CODON

Answer 14

A triplet nucleotide base sequence on the tRNA which matches with the complementary triplet on the mRNA

Question 15

DEGENERACY

Answer 15

More than one codon for a particular amino acid.
The degenerative code reduces the possible effect of point substitution mutations, as a base change may result in no change to the subsequent amino acid coded for (silent mutation)

Question 16

RIBOSOME

Answer 16

Cell organelle which is the site for protein synthesis

Question 17

POINT MUTATION

Answer 17

The change in one base in the sequence of DNA

Question 18

FRAMESHIFT MUTATION

Answer 18

A type of gene mutation wherein the addition or deletion of a nucleotide causes a shift in the reading frame of the codons in the mRNA, which may eventually lead to the alteration in the amino acid sequence at protein translation

Question 19

METABOLISM

Answer 19

The sum of all the chemical reactions within an organism

Question 20

METABOLIC PATHWAY

Answer 20

A series of enzyme controlled chemical reactions where the product of one reaction becomes the substrate for the next

Question 21

PHENOTYPE

Answer 21

The observable traits of an organism, resulting from the interactionb between an organism’s genes and environment

Question 22

CHROMOSOME

Answer 22

The large storage structure of genetic information (DNA) found in the nucleus. Humans have 46 chromosomes which come in pairs, 23 inherited from each parent in the gametes

Question 23

NUCLEOTIDE

Answer 23

The sub-untis of nucleic acids DNA and RNA, made up of sugar, phosphate and base. The bases are Adenine, Thymine, Guanine and Cytosine in DNA, with Uracil replacing Thymine in RNA

Question 24

RNA

Answer 24

A nucleic acid which there are three types mRNA, tRNA and rRNA. This molecule is single-stranded, relatively short, contains a ribose sugar and bases Adenine, Uracil, Guanice and Cytosine

Question 25

MUTATION

Answer 25

An irreversible change to the genetic information of an individual

Question 26

GAMETIC MUTATION

Answer 26

Mutations which occur in gametes (sperm and eggs). These mutations are inheritable (able to be passed on to offspring)

Question 27

SOMATIC MUTATION

Answer 27

Mutations which occur in somatic (body) cells. These mutations are non-inheritable and are therefore not passed on to offspring

Question 28

MUTAGENS

Answer 28

Something which speeds up the rate at which mutations are likely to occur. Examples include radioactive substances, chemicals, ionising radiation and microorganisms

Question 29

POINT MUTATION

Answer 29

Mutations which change, insert or delete a single base nucleotide. Sometimes called gene mutations

Question 30

BASE SUBSTITUTIONS

Answer 30

Where there is a single base change in the genetic code

Question 31

DELETIONS

Answer 31

Deletion of a single base from the DNA sequence

Question 32

INSERTIONS

Answer 32

Insertion of a single base into the DNA sequence

Question 33

BENEFICIAL MUTATIONS

Answer 33

Mutations which confer and adaptive change (survival and/or reproduction) on the individual. These mutations may increase in frequency in the gene pool as they are favourable and through the population

Question 34

HARMFUL MUTATIONS

Answer 34

Mutations which are maladaptive to the individual and are selected against. These mutations are not likely to persist in the gene pool and will decrease in frequency or disappear altogether

Question 35

NEUTRAL MUTATIONS

Answer 35

Mutations which change the protein produced and have an effect on the phenotype, but are neither beneficial nor harmful to the individual’s survival or reproduction. Neutral mutations can persist in the population and may become beneficial or harmful if the environment changes

Question 36

SILENT MUTATIONS

Answer 36

As there are multiple codes for most amino acids, a substitution mutation may result in the same amino acid being coded for and the polypeptide is unchanged despite the change to the DNA. A silent mutation changes the DNA, but there is no change to the protein product