8: DNA, Genes and Protein Synthesis

Question 1

Allele

Answer 1

One of a number of forms of a gene

Question 2

Anticodon

Answer 2

A sequence of three bases on tRNA

Question 3

Chance

Answer 3

The occurrence of events in the absence of any obvious cause.

Question 4

Chromatin

Answer 4

The material that makes up chromosomes. It consists of DNA and the protein histone.

Question 5

Chromatids

Answer 5

One of the two strands of a chromosome that are joined together by a single centromere

Question 6

Deletion

Answer 6

A gene mutation when a nucleotide is lost from a sequence thus affecting the codon in the location of the deletion and all subsequent codons.

Question 7

Chromosomes

Answer 7

A thread-like structure made of proteins and DNA by which hereditary information is physically passed from one generation to the other

Question 8

Codon

Answer 8

The sequence of three bases on mRNA that codes for a single amino acid

Question 9

Degenerate

Answer 9

Most amino acids are coded for by more than one triplet

Question 10

Gene

Answer 10

Section of DNA on a chromosome coding for one or more polypeptides

Question 11

Exons

Answer 11

Coding sequences

Question 12

Gene Mutations

Answer 12

A change to one or more nucleotide bases in DNA resulting in a change genotype which may be inherited.

Question 13

Diploid number

Answer 13

A term applied to cells in which the nucleus contains two sets of chromosomes

Question 14

Locus

Answer 14

A section of DNA that is located at a particular position

Question 15

Genome

Answer 15

The complete set of all genes in a cell

Question 16

Histones

Answer 16

The protein that eukaryotic DNA associates with in chromosomes

Question 17

Homologous pairs

Answer 17

A pair of chromosomes that have the same gene loci and therefore determine the same features

Question 18

Haploid number

Answer 18

A term referring to cells that contain only a single copy of each chromosome

Question 19

Introns

Answer 19

Non-coding sequences

Question 19

mRNA (messenger RNA)

Answer 19

The type of RNA that transfers the DNA code from the nucleus to the cytoplasm, acts as a type of messenger

Question 21

Non-overlapping

Answer 21

Each base is only included in one triplet code, each base in this sequence is only read once

Question 21

Mutagenic

Answer 21

A factor that can cause mutations, such as ionising radiation or certain organic chemicals

Question 22

Promoter

Answer 22

Sequence of DNA prior to to a gene to which transcription factors (and so RNA polymerase) can bind.

Question 23

Proteome

Answer 23

The full range of proteins produced by the genome

Question 24

Ribose

Answer 24

Pentose sugar found in RNA

Question 24

RNA polymerase

Answer 24

Enzyme required for transcription that is responsible for breaking hydrogen bonds in a DNA molecule and simultaneously forming phosphodiester bonds in a mRNA molecule.

Question 27

Transcription

Answer 27

The process where pre-mRNA is synthesised from DNA

Question 28

Splicing

Answer 28

The process where introns are removed from pre-mRNA to form mRNA

Question 29

Template strand

Answer 29

A strand of DNA which acts as a template for pre-mRNA synthesis

Question 30

Substitution

Answer 30

A gene mutation where one nucleotide is replaced with another thus only affecting the codon in the location of the substitution (unless it produces a stop codon).

Question 31

Translation

Answer 31

The process where mRNA is used as a template to form a polypeptide

Question 32

tRNA

Answer 32

RNA molecule shaped like a clover-leaf with an attached amino acid that is specific to the anticodon on the other side of the molecule.

Question 33

Universal

Answer 33

Each triplet codes for the same amino acids in all organisms

Question 34

Uracil

Answer 34

Nucleotide base in RNA. Pairs with adenine