DNA, genes and protein synthesis

Question 1

what is a gene?

Answer 1

a section of DNA that contains the coded information for making polypeptides and functional RNA

Question 2

give 2 features of the genetic code:

Answer 2

it is universal and non-overlapping

Question 3

what does it mean by the genetic code being universal?

Answer 3

each triplet codes for the same amino acid in all organisms. this is indirect evidence for evolution

Question 4

what does it mean by the genetic code being non-overlapping?

Answer 4

each base in the sequence is read only once. e.g: six bases numbered 123456 are read in triplets of 123 456, instead of 123 234 345 …

Question 5

what is the name of coding DNA (DNA that codes for polypeptides)?

Answer 5

exons

Question 6

what is the name of non-coding DNA (DNA that doesn’t code for polypeptides)?

Answer 6

introns

Question 7

what do introns often code for?

Answer 7

ribosomal and transfer RNA

Question 8

what is an allele?

Answer 8

one of a number of alternative forms of a gene