Week 8

Question 1

What is the medical example and explain it

Answer 1

Drug resistance; resistance to a new antibiotic can involve over a number of years

Question 2

Name the two mechanisms for variation

Answer 2

Mutation and recombination

Question 3

Explain recombination

Answer 3

Can lead to variations in existing dna

Question 4

mutation within a gene

Answer 4

An existing gene
can be modified by a mutation that changes
a single nucleotide or deletes or duplicates
one or more nucleotides.

Question 5

Mutation within regulatory DNA sequences:

Answer 5

When and where a gene is expressed can be
affected by a mutation in the stretches of
DNA sequence that regulate the gene’s
activity.

Question 6

gene duplication and divergence:

Answer 6

existing gene, or even a whole genome, can
be duplicated.

Question 7

exon shuffling

Answer 7

Two or more existing genes
can be broken and rejoined to make a hybrid
gene containing DNA segments that
originally belonged to separate genes.

Question 8

Transposition of mobile genetic elements:

Answer 8

Specialized DNA sequences that can move
from one chromosomal location to another
can alter the activity or regulation of a gene;
they can also promote gene duplication,
exon shuffling, and other genome
rearrangements.

Question 9

What are the features of homologous recombination?

Answer 9

1. Two DNA double helices with
   regions of similar sequence line
   up so they are in register
2. A site of DNA exchange
   (crossover point) occurs at some
   point in the region of similarity
3. No nucleotides are are lost or
   gained

Question 10

Plasmids

Answer 10

small-circular mini chromosomes

Question 11

Conjugation

Answer 11

Movement of a plasmid to a new cell

Question 12

Capsid

Answer 12

Protein coat

Question 13

Exons

Answer 13

Protein coding regions

Question 14

introns

Answer 14

non protein coding regions