Structure and function of human genome

Question 1

For chromosome, what does p arm mean?

Answer 1

Short arm

Question 2

For chromosome, what does q arm mean?

Answer 2

Long arm

Question 3

What are the types of chromosomes called in order?

Answer 3

1) metacentric
2) sub-metacentric
3) acrocentric
4) telocentric

Question 4

What ways do scientist use to identify different chromsomes?

Answer 4

1) size
2) banding pattern
3) centromere position

Question 5

How many histones are needed to form a nucleosome?

Answer 5

8 (octamer of histones)

linker dna leads to the next nucleosome

Question 6

When DNA wraps around histone molecules and there are multiple nucleosomes what structure does it create?

Answer 6

Solenoid structure

Question 7

What is a chromatin that is in an extended state, dispersed through the nucleus and allows gene expression?

Answer 7

Euchromatin

Question 8

What is a chromatin that is highly condensed and genes not expressed?

Answer 8

Heterochromatin

Question 9

What are 2 unique characteristics and functions of centromeres?

Answer 9

1) Rich in heterochromatin

2) highly repetitive

Question 10

What are the protein coding gene called? (1.5%)

Answer 10

Exome

Question 11

What are the protein coding gene called? (1.5%)

Answer 11

Exome

Question 12

Which part of exons don’t code for amino acids?

Answer 12

The untranslated regions like the 5’UTR & 3’UTR

Question 13

What are UTR?

Answer 13

It is untranslated regions that contain regulatory elements (important for control of protein synthesis)

Question 14

What is a nuclear genome?

Answer 14

It is made out of 22 pairs of autosomes and 1 pair of sex chromosomes.
Transcribed unit = genes
- Protein coding
-RNA only coding (non coding transcripts that make RNA but not protein)

Question 15

What is a mitochondrial genome?

Answer 15

Every mitochondria has the mitochondrial genome.

- 16Kb compared to 3000 Mb (nuclear genome)

Question 16

What is your genome?

1) Material =
2) Packages =
3) Genes? =
4) Just genes? =
5) How big is it? =
6) All DNA in cell (nuclear) and mitochondrial DNA? =

Answer 16

1) DNA
2) Chromatin and chromosomes
3) Yes
4) No
5) Big
6) Yes

Question 17

What bases are purines?

Answer 17

Adenine and Guanine

Question 18

What bases are pyrimidines?

Answer 18

Cytosine, Thymine and Uracil

Question 19

What is an epigenome?

Answer 19

Chemical compounds that attach to DNA or histones and can affect gene activity (DNA methylation and histone acetylation)

Question 20

What can epigenome do in affecting gene activity (6 things)?

Answer 20

1) Alter chromatin structure (turn euchromatin into heterochromatin)
2) Recruit histone modifiers
3) Repress transcription
4) Genome-wide pattern established at fertilisation
5) Important for differential gene expression (transcription)
6) Responds to environmental cues (cellular and external)

Question 21

If all cells have the same genome, why don’t all cells look the same?

Answer 21

It is due to the differential gene expression.

• It differs temporally (time) e.g. development (embryo needs different genes compared to adults) & in response to hormones, infection and other signals
• Spatial differentiation as different tissue and cells express different genes

Question 22

Failure leads to what conditions?

Answer 22

1) Metabolism
2) Metastasis
3) Congenital disorders
4) Cancer