Definitions

Question 1

DNA Template

Answer 1

The DNA template strand is the strand that the mRNA is made from. It is complementary to the mRNA strand

Question 2

mRNA

Answer 2

mRNA is “messenger” RNA. It is made during transcription in the nucleus. It carries the instructions to the ribosome to make a polypeptide chain and contains codons.

Question 3

tRNA

Answer 3

tRNA is “transfer” RNA that is complementary to the mRNA. It’s anticodon ensures that the correct amino acid is added to the growing polypeptide chain (as the Ribosome reads the mRNA).

Question 4

Ribosome

Answer 4

The Ribosome is the structure that “reads” the mRNA and, through the use of tRNA, adds amino acids that correspond to each codon on the mRNA until a stop codon is reached

Question 5

Polypeptide chain

Answer 5

The polypeptide chain is the name of the chain of Amino acids which will fold together to make a protein.

Question 6

Transcription

Answer 6

Transcription is the process where mRNA is made from the template strand of DNA in
the nucleus

Question 7

What is the process of transcription?

Answer 7

This process involves the DNA unwinding into two single strands. An enzyme will then
bind to the template strand of DNA at the promoter region. This enzyme will move along
the DNA adding complementary RNA bases (A-U, C-G) until a terminating region is
reached. The completed strand of mRNA will now leave the nucleus. The two strands of
DNA will bind back together. This is the end of transcription.

Question 8

Translation

Answer 8

Translation is the process where the mRNA is read by the ribosome in the cytoplasm and
an amino acid chain is created based on the codons on the mRNA.

Question 9

What is the process of translation?

Answer 9

This process involves the Ribosome binding to the start of the mRNA strand. The
ribosome will move along the mRNA reading it in threes (codons). tRNA, with three
complementary bases (called anticodons) to the mRNA codons, will enter the ribosome
and drop off their attached amino acid. The tRNA will then leave for another tRNA to
enter the ribosome and drop off its amino acid. These amino acids are joined together by
the ribosome forming a polypeptide chain. This process continues until the ribosome
encounters a stop codon. At this point the mRNA will leave the ribosome, the polypeptide
chain will also detach. This is the end of translation.

Question 10

Enzyme

Answer 10

A folded protein which acts as a biological catalyst to speed up the rate of chemical reaction in an organism

Question 11

Metabolic pathway

Answer 11

A metabolic pathway is a series of enzyme-controlled reactions, where
the product of one reaction is the substrate for the next.

Question 12

Anticodon

Answer 12

Three consecutive bases on the tRNA

Question 13

Codon

Answer 13

Three consecutive bases on the mRNA

Question 14

Deletion mutation

Answer 14

A mutation on the DNA where a base(s) is removed, resulting in a frame shift

Question 15

DNA

Answer 15

Deoxyribose nucleic acid, A joins with T, C joins with G. Double stranded, helix shaped large molecule, a whole chromosome. Deoxyribose sugar.

Question 16

Frameshift

Answer 16

Change in bases that the ribosome reads

Question 17

Gene

Answer 17

A piece of DNA which codes for the making of a protein / feature.

Question 18

Gene expression

Answer 18

The process where the instructions on our DNA are converted into a functional protein, includes transcription, translation and protein folding

Question 19

Genotype

Answer 19

The genetic make-up of an organism for a feature

Question 20

Insertion mutation

Answer 20

A mutation on the DNA where a base(s) is added resulting in a frame shift

Question 21

Missense mutation

Answer 21

A change of the base on the DNA which codes for a different amino acid. This may or may not alter the shape of the protein and therefore it’s function

Question 22

Phenotype

Answer 22

Phenotype is the physical expression of the genetic information in the DNA.

Question 23

Mutagen

Answer 23

A mutagen is an environmental factor that changes the DNA

base sequence / increases the rate of mutations

Question 24

Example of a mutagen

Answer 24

An example of a mutagen is ionising radiation, X-rays, alcohol,
cigarette smoke, microorganisms etc. NOT just chemicals /
toxins.

Question 25

Triplet

Answer 25

3 consecutive bases on DNA strand

Question 26

Triplet

Answer 26

3 consecutive bases on DNA strand