Definitions

Question 1

What is a chromosome?

Answer 1

DNA and histones are organised into structures that are called chromosomes

Question 2

What is a gene?

Answer 2

A sequence of DNA bases that codes for the specific amino acid sequence of a polypeptide

Question 3

What is a homologous pair of chromosomes?

Answer 3

Carries the same genes in the same loci but not necessarily the same alleles

Consist of a maternal and paternal chromosome

Question 4

What is a locus?

Answer 4

The fixed position that a gene occupies on a particular DNA molecule or chromosome

Question 5

What is an allele?

Answer 5

Different forms of a gene

Question 6

What are histones?

Answer 6

The proteins that DNA is wrapped around in eukaryotes

Question 7

What is a base triplet?

Answer 7

A sequence of three nucleotide bases that codes for a specific amino acid

Question 8

What are codons?

Answer 8

Base triplets in mRNA

Question 9

What does degenerate mean?

Answer 9

Different triplets or codons coding for the same amino acid

Question 10

What are stop codes?

Answer 10

Indicate the end of the code for a specific polypeptide

Question 11

What is a start code?

Answer 11

Indicate the start of the code for a specific polypeptide

Question 12

What does non-overlapping mean?

Answer 12

Each base is only read once as part of a specific triplet

Question 13

What does universal mean?

Answer 13

The same triplets code for the same amino acids in all organisms

Question 14

What does reading mRNA mean?

Answer 14

When the ribosome moves along the mRNA reading codons

Question 15

What are introns?

Answer 15

Base sequences present WITHIN genes but DO NOT code for amino acids.

Question 16

What are exons?

Answer 16

The base sequence in genes that DO code for amino acids.

Question 17

What are multiple repeats?

Answer 17

Some of the base sequences present BETWEEN genes

Question 18

What are anticodons?

Answer 18

3 unattached tRNA nucleotide bases

Question 19

What is a genome?

Answer 19

The complete set of genes (and non-coding DNA)in a cell

Question 20

What is a proteome?

Answer 20

The full range of proteins that a cell is able to produce

Question 21

What is pre-mRNA?

Answer 21

The mRNA formed during transcription using DNA containing both exons and introns

Question 22

What is genetic diversity?

Answer 22

The number of different alleles in a population

Question 23

What are genetic mutations?

Answer 23

Change in the base sequence caused by errors in DNA replication

Question 24

What is chromosome mutations?

Answer 24

Change in number/structure of chromosomes caused by errors in cell division

Question 25

What is a mutagenic agent?

Answer 25

A factor that increases mutation rate, it makes spontaneous mutations more likely

Question 26

What is substitution?

Answer 26

The replacement of one or more bases by one or more different bases

Question 27

What is deletion?

Answer 27

The removal of one or more bases

Question 28

What is addition?

Answer 28

The adding of one or more bases

Question 29

What is duplication?

Answer 29

Where one or more bases is repeated

Question 30

What is inversion?

Answer 30

Where a sequence of bases is reversed?

Question 31

What is translocation? (Mutations)

Answer 31

Where a sequences of bases is moved from one location in the DNA molecule to another part of the genome

Question 32

What is a frame shift?

Answer 32

The alteration in all the triplets from the point of mutation

Question 33

What is a diploid cell?

Answer 33

A cell with the full number of chromosomes

Question 34

What is a haploid cell?

Answer 34

A cell with half the number of chromosomes. One from each homologous pair

Question 35

What is meiosis?

Answer 35

A type of nuclear division that produces cells that are genetically different