DNA, genes and chromosomes

Question 1

DNA in prokaryotic cells

Answer 1

DNA molecules are short, circular and not associated with proteins

Question 2

DNA in eukaryotic cells

Answer 2

DNA molecules are very long, linear and associated with proteins, called histones

Question 3

Chromosome

Answer 3

DNA molecule and its associated proteins

Question 4

Gene

Answer 4

A gene is a base sequence of DNA that codes for:
the amino acid sequence of a polypeptide
a functional RNA (including ribosomal RNA and tRNAs)

Question 5

Locus

Answer 5

A gene occupies a fixed position, called a locus, on a particular DNA molecule

Question 6

Triplet

Answer 6

A sequence of three DNA bases, called a triplet, codes for a specific amino acid.

Question 7

Genetic code is…

Answer 7

The genetic code is universal, non-overlapping and degenerate

Question 8

Universal

Answer 8

The genetic code is universal because all species use the same four bases A,T,C and G, and each base sequence codes for the same amino acid in all species

Question 9

Non-overlapping

Answer 9

This means that each codon codes only for its particular amino acid. It does not specify the positions of other amino acids on the final protein

Question 10

Degenerate

Answer 10

The degenerate code refers to the fact that multiple codons, or sets of three nucleotides, can code for the same amino acid during protein synthesis

Question 11

Introns

Answer 11

Non-coding sections of DNA

Question 12

Exons

Answer 12

Coding regions of DNA