3.4.1 DNA Genes And Chromosomes

Question 1

Differences and similarities in DNA from eukaryotic vs prokaryotic

Answer 1

Similarities:
-nucleotide structure is the same
-nucleotides joined by phosphodiester bonds. Complementary bases joined by hydrogen bonds

Differences:
-eukaryotic DNA is longer, linear (pro is circular)
- eukaryotic DNA is associated with histones proteins (pro isn’t)
-eukaryotic DNA contains introns (pro dosent )

Question 2

What is a chromosome

Answer 2

Long linear DNA and its associated histone proteins

In the nucleus of eukaryotic cells

Question 3

What is a gene

Answer 3

Sequence of DNA (nucleotide) bases that code of a amino acid sequence of a polypeptide or functional RNA

Question 4

What is a locus

Answer 4

Fixed position a gene occupies on a particular DNA molecule

Question 5

Why is the genetic code a triplet, universal, non- overlapping and degenerate

Answer 5

Triplet code- 3 DNA bases code for a specific amino acid

Universal - same bast triplets code for the same amino acid in all organisms

Non-overlapping - each base is only 1 triplet, so they are read as a discrete unit

Degenerate - amino acid can be coded for by more than one base triple

Question 6

What are non-coding sequences and where are they found

Answer 6

They don’t code for amino acids

Found between genes or witching genes (introns)

Question 7

What are introns and exons

Answer 7

Exons- base sequence of a gene that codes of an amino acid sequence

Introns -dosent code for amino acids