Introns And Exons/mutations

Question 1

What are exons?

Answer 1

Part of DNA that codes for polypeptides?

Question 2

What are introns?

Answer 2

Repeated sequence of bases not coding for a polypeptide.

Question 3

What is process of splicing?

Answer 3

1. Gene composed of exons and introns transcribed to RNA by RNA polymerase
2. Processing involves ribozymes and proteins in the nuclear to remove the intron RNA a s Alice together exon RNA into mRNA.
3. Then mRNA travels to cytoplasm for protein synthesis

Question 4

What is difference between eukaryotic and prokaryotic genes

Answer 4

Eukaryotic: usually discontinuous, have exons and non coding introns
Prokaryotic: continuous, containing only exons

Question 5

What are gene mutations and what are 4 ways?

Answer 5

Changes to base pairs within genes
1. Base substation - one base replaces another
2. Base addition - one or more bases added to sequence
3. Base deletion - one or more base lost from sequence
4. Inversion - triplet sequence inverted

Question 6

What is a degenerative mutation?

Answer 6

Where different triplet sequences code for same amino acid so less affect

Question 7

What is silent mutation?

Answer 7

One with no effect

Question 8

What is a neutral mutation

Answer 8

Where altered amino acid is not esssentiak for tertiary/quaternary structure of protein

Question 9

What is sickle cell anaemia?

Answer 9

Where single base substation for beta haemoglobin causes secondary, tertiary and quartnerary structure changes