Lecture 2 and 3 Genetics (vertical - Annika)

Question 1

All/almost call diseases have a genetic/hereditary contribution - what does this mean?

Answer 1

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Question 2

What three things affect health?

Answer 2

Environment, choices and genes

Question 3

What is gene expression? What are the two products?

Answer 3

The process by which information from a gene is used in the in the synthesis of a function gene product (usually a protein but sometimes ncRNA)

Question 4

For both protein and ncRNA - what process is essential (and common) for gene expression? Describe the initiation of the process

Answer 4

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Question 5

Okay, for DNA to protein - you get the DNA (info) from a gene i.e. particular DNA and then via mRNA you get a coding gene product (protein) which performs the cell’s various biological functions. But how is that process for DNA to ncRNA? What does ncRNA produce do?

Answer 5

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Question 6

Regulation of gene expression:

1. Not all genes are actively expressed at the same time - true?
2. What is normal gene expression and what are the three criteria for it being normal?
3. Abnormal gene expression is when there is any of the below: ….?

Answer 6

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Question 7

What is a gene?

Answer 7

A sequence of DNA that specifies the production of a functional product (protein or ncRNA)

Question 8

Every nucleated cell in the body carries its own copy of the human genome - same DNA (minus mutations) In every cell. What about the DNA in mitochondria? What can you say about that? Where is that inherited from?

Answer 8

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Question 9

What’s the function of each of the following:

1. Coding sequence
2. Promoter
3. 5’ UTR and 3’ UTR - are they transcribed/translated?
4. Introns
5. 5’ G cap
6. Poly-A-tail

Answer 9

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Question 10

Enhancers and Silencers:

1. Are they long or short?
2. Are they near or far away from the gene they regulate - how many base pairs?
3. Are they upstream or downstream or within the gene they control?
4. So their position and orientation is independent of the _______ ______ site (in contrast to promoters)
5. What do they do that increases the rate of transcription?
6. How do silencers work?

Answer 10

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Question 11

Enhancer blocker insulators:

1. They are DNA sequences that prevent what? When are they necessary?
2. What are they located between?
3. It will bind proteins which do what?
4. What does it determine?

Answer 11

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Question 12

􀀄􀀐􀀈􀀔􀀒􀀁􀀈􀀐􀀏􀀓􀀑􀀐􀀍􀀁􀀑􀀉􀀋􀀌􀀐􀀏􀀒􀀁􀀗􀀄􀀂Locus control regions

1. Have the same features and act like enhancers but what? (2)

Answer 12

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Question 13

DNA sequence of adult beta globin gene:

1. CAT box - what is it (more important than TATA or nah?), where is it and is it always present?
2. TATA box - where is it and is it always present on all genes?
3. What is before the first exon but more or less part of it? What about last exon?
4. When introns get cut, what are the splice sites and is it possible for them to be in the middle of a Condon in the exon?
5. ATG - start codon but in eukaryotes, is the first methionine there or removed?

Answer 13

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Question 14

What other genomic aspect can affect gene expression or the function of regulatory elements?

Answer 14

Jumping gene

Question 15

Transposable elements (TEs) - jumping genes

1. What percentage of our genome is made up of TEs?
2. Why are they considered selfish genes?
3. Involved in causing genetic disease if it ‘jumps into’ a ____ or ______ gene or ______ _____
4. Many TEs carry their own promotor, so if such a TE moves close to a gene, the TE’s promotor can cause what?

Answer 15

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Question 16

Remember:

1. There is lots of normal genetic variation between individuals, which gives rise to variation in ‘normal’ gene expression
2. There is much less variation in important genes (highly conserved genes) and/or what?

Answer 16

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Question 17

1. Changes in the DNA happens relatively frequently and there is lots of ______ in the human genome i.e. sequence variation that is common buuuuut when the DNA sequences change in such way that it deviates away from the normal common variants (they arise through the same mechanisms as polymorphisms though), the DNA change is referred to as _____
2. Mutations can be neutral, _____, ______

Answer 17

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Question 18

The effect of a mutation on its gene product will depend on what three things?

Answer 18

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Question 19

Three mutations: chromosomal, sub chromosomal, and DNA

Chromosomal:

• number of what changes?
• due to missegregation during what?
• is it the common human mutation?
• what severe gene dosage consequence does it lead to?

Subchromosomal:

• what changes?
• what are the 5 types and which two are the worst? how are the other three bad?
• also can lead to early natural abortion, right?

DNA:

• smaller alterations
• caused by what that arises after replication and aren’t corrected (due to m____)
• most common _____ human mutations

Answer 19

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Question 20

DNA mutations:

1. What are synonymous and non-synonymous substitutions?
2. Explain the following: silent, missense, nonsense, frameshift
3. What are dynamic mutations?
   - expansion of ____ DNA repeat sequence beyond what?
   - usually how many nucleotides repeat?
   - leads to abnormal what?

Answer 20

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