L1

Question 1

What causes variability in physiological differences?

Answer 1

1. Environment

2. Genetic makeup (0.1% in the genome is the variability!)

Question 2

What is a regulatory element?

Answer 2

Functional DNA elements that regulate gene expression

Question 3

What is an anonymous region?

Answer 3

DNA locus without any apparent function (non-functional region)

Question 4

How is genetic variability introduced?

Answer 4

1. Large scale chromosomal changes
2. Generation of new alleles
3. Changes in gene expression

Question 5

The structure of DNA fulfilled the 3 main requirements for a hereditary molecule:

Answer 5

1. Ability to store information
2. Ability to be replicated
3. Ability to be changed, mutated

Question 6

How do polymorphisms arise?

Answer 6

1. Changes in the sequences of dNTPs

2. Changes in the 3 of dNTPs

Question 7

What are polymorphisms caused by?

Answer 7

1. Random replication error

2. Exposure to mutagens

Question 8

Changes in DNA sequence of the protein-coding region of a gene ->

Answer 8

altered mRNA sequence -> may result in altered amino acid sequence -> may result in changes in protein structure an function

Question 9

Changes in DNA sequence of regulatory elements ->

Answer 9

may alter gene expression -> may result in changes in protein levels

Question 10

DNA replication is semiconservative:

Answer 10

• Each parental DNA strand acts as a template for the synthesis of daughter strands
• Daughter chromosomes each receive one parental strand and one daughter strand

Question 11

Most polymorphisms have no effect:

Answer 11

• mutations in an anonymous locus (non-functional element)
• Repair mechanisms are in place to fix replication errors or induce cell death
• Neutral polymorphisms in protein-coding elements

Question 12

When polymorphisms have a phenotypic effect, they can either:

Answer 12

1. Increase survival (evolution)

2. Cause pathological conditions (disease)