DNA, chromosomes and the genetic code

Question 1

define a gene

Answer 1

a section of DNA with a specific base sequence that codes for a specific protein with a specific function

Question 2

aside from the nuclear envelope, in eukaryotic cells what also contains DNA

Answer 2

• mitochondria
• chloroplasts

Question 3

how many amino acids are there

Answer 3

20

Question 4

how many triplets (/codons) can code for the amino acids

Answer 4

4x4x4 = 64

Question 5

name the four key features of the genetic code

Answer 5

• the code is read in triplets, 3 bases code for a single amino acid
• triplets are non overlapping (each base is only read once)
• the code is universal (same triplets code for the same amino acids in every organism)
• degenerate code- most amino acids are coded for by more than one triplet