Key Concepts for Frontiers in Neuroscience

Question 1

What does aetiology mean?

Answer 1

The cause, set of causes, or manner of causation of a disease or condition

Question 2

What one of the following statements is correct?

A. RNA polymerases perform translation, a process during which DNA sequence is used to make an RNA molecule
B. RNA polymerases perform transcription, a process during which DNA sequence is used to make an RNA molecule
C. DNA polymerases perform transcription, a process during which DNA sequence is used to make an RNA molecule
D. RNA polymerases perform translation, a process during which DNA sequence is used to make an RNA molecule

Answer 2

B. RNA polymerases perform transcription, a process during which DNA sequence is used to make an RNA molecule

Question 3

What are the coding regions of the DNA called?

Answer 3

Exons

Question 4

What are the non-coding regions of the DNA called?

Answer 4

Introns

Question 5

When a primary transcript is created from DNA what is this process called?

Answer 5

Transcription

Question 6

What is at the starting end of the mRNA?

Answer 6

A 5’ cap

Question 7

What is at the end of the mRNA?

Answer 7

3’ poly-A-tail

Question 8

What is the process of removing introns to make the final mRNA?

Answer 8

Splicing

Question 9

What is the process where proteins are made from RNA?

Answer 9

Transcription

Question 10

What is the proportion of human genome which contains gene coding proteins?
A. 2% B. 10% C. 15% D. 25% E. 50% F. 75% G. 90%

Answer 10

A. 2%

The rest of the genome just consist of introns or regulatory elements and do not directly get translated into proteins.

Question 11

How many genes does the human genome have?

Answer 11

20 - 25,000 genes

Question 12

What is an open reading frame?

Answer 12

Open reading frame (ORF) is the part of a reading frame that has the ability to be translated. An ORF is a continuous stretch of codons that contain a start codon (usually AUG) and a stop codon (usually UAA, UAG or UGA).

Question 13

What is the main functions of the 5’ cap?

Answer 13

Regulation of nuclear export
Stabilisation - prevents degradation by exonucleases
Promotion of translation

Question 14

What is the main functions of the polyA tail?

Answer 14

Regulation of nuclear export
Stabilisation
Helps to terminate transcription
Helps on further steps of protein synthesis

Question 15

What are the four bases?

Answer 15

A = Adenine
T = Thymine
C = Cytosine
G = Guanine

Question 16

What are the three base parity rules?

Answer 16

The number of As = Ts and Cs = Gs.
A + T = C + G.
Amount of G + C is species specific.

Question 17

What are the four different point mutations?

Answer 17

Substitution
Insertion
Deletion
Inversion

Question 18

How many autosomes are there in a human genome?

A. 20 B. 21 C. 22 D. 23

Answer 18

C. 22

Question 19

What is an autosome?

Answer 19

Any chromosome that is not a sex chromosome

Question 20

What is the copy number variation (CNV)?

Answer 20

The variation in the number of copies (normally two) of a gene, or of sequences of DNA in the genome of a specific individual.

Question 21

What is the copy number polymorphism (CNP)?

Answer 21

The normal variation in the number of copies (normally two) of a gene, or of sequences of DNA, in the genome of a specific individual.

Question 22

Undergraduate student Zoe working on a project characterising morphology of astrocytes in an animal model of depression. For this she uses a transgenic mouse model expressing green fluorescent protein under the promoter of glial fibrillary acidic protein. Does Zoe need to perform immunohistochemistry to identify astrocytes in amygdala?

A. Yes B. No

Answer 22

B. No ?

Question 23

What is a point mutation?

Answer 23

Point mutations mean there is only one nucleotide that has changed in the sequence

Question 24

What are the four different chromosome mutations that can occur?

Answer 24

Deletions
Translocation
Duplication
Inversion

Question 25

What is a missense mutation?

Answer 25

A change in one DNA base pair that results in a substitution of one amino acid for another in the protein made by a gene

Question 26

What is a nonsense mutation?

Answer 26

A change in one base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.

Question 27

What is an insertion?

Answer 27

Changes the number of DNA bases in a gene by adding a piece of DNA. As a result, the protein made by the gene may not function properly

Question 28

What is a deletion?

Answer 28

Changes the number of bases by removing a piece of DNA. Small deletions may remove one or a few base pairs within a gene, while larger deletions can remove an entire gene or several neighbouring genes. The deleted DNA may alter the function of the resulting protein(s).

Question 29

What is duplication?

Answer 29

Consists of a piece of DNA that is abnormally copied one or more times. This type of mutation may alter the function of the resulting protein.

Question 30

What is a frameshift mutation?

Answer 30

Occurs when the addition or loss of DNA bases changes a gene’s reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. The resulting protein is usually non-functional. Insertions, deletions, and duplications can all be frameshift mutations.

Question 31

What is a repeat expansion?

Answer 31

Nucleotide repeats are short DNA sequences that are repeated a number of times in a row. For example, a trinucleotide repeat is made up of 3-base-pair sequences, and a tetranucleotide repeat is made up of 4-base-pair sequences. A repeat expansion is a mutation that increases the number of times that the short DNA sequence is repeated. This type of mutation can cause the resulting protein to function improperly.

Question 32

What is a somatic mutation?

Answer 32

The occurrence of a mutation in the somatic tissue of an organism, resulting in a genetically mosaic individual