B1 Genetics

Question 1

What is a gene?

Answer 1

A distinct sequence of nucleotides forming part of chromosome.The order determines the order of monomers in a polypeptide/ nucleic acid molecule that the cell may synthesise

Question 2

What is the purpose of non-coding RNAs?

Answer 2

Controlling levels of genes that do code for proteins

Question 3

What is the process that converts DNA to pre-mRNA?

Answer 3

Transcription

Question 4

What is the process that converts pre-mRNA into mRNA?

Answer 4

Splicing

Question 5

What is the process that makes protein from mRNA?

Answer 5

Translation

Question 6

How is the location and time of gene transcription controlled?

Answer 6

Promoter and regulatory sequences

Question 7

What enzyme is responsible for the transcription of the gene?

Answer 7

RNA polymerase(DNA helicase helps!)

Question 8

What is the role of transcription factors?

Answer 8

They bind to the promoter and regulatory sequences and influence gene transcription

Question 9

Which strand is the template strand? Sense or antisense?

Answer 9

Antisense

Question 10

Which DNA strand corresponds with the amino acid selected?

Answer 10

Sense

Question 11

In addition to splicing, what modifications occurbefore translation?

Answer 11

CappingPolyadenylation

Question 12

What is capping?

Answer 12

Cap structure is added to the 5’ end of the mRNAs shortly after the beginning of transcription

Question 13

What is polyadenylation?

Answer 13

Poly-A polymerase adds 100 to 300 Adenine residues to form a poly-A tail on the 3’ end.

Question 14

How are the levels of mature mRNA regulated after transcription?

Answer 14

microRNAs destabilise them and inhibit initiation of their translation

Question 15

What is the process that microRNAs are responsible for?

Answer 15

RNA-induced silencing

Question 16

The genetic code is degenerate, but unambiguous. What does this mean?

Answer 16

An amino acid can have more than one codon, but no codon codes for two different amino acids.

Question 17

What is the start codon/ initiator and what does it code for?

Answer 17

AUG - Methionine

Question 18

What is the stop codon known as?

Answer 18

Open reading frame (ORF)

Question 19

What is the small ribosomal sub-unit responsible for?

Answer 19

Binding mRNA and tRNA

Question 20

What is the large ribosomal sub-unit responsible for?

Answer 20

Catalyzes addition of amino acids to extending peptide chain.

Question 21

What end of the mRNA does the small sub-unit scan from?

Answer 21

5’ end

Question 22

What end is the initiator at on the mRNA?

Answer 22

5’ end

Question 23

In termination, what recognises the stop codon?

Answer 23

A releasing factor

Question 24

What are releasing factors responsible for?

Answer 24

Causing the ribosome complex to fall apart; ending translation

Question 25

True or false? Many antibiotics are inhibitors of protein synthesis in bacteria?

Answer 25

True

Question 26

What is the key to good antibiotics?

Answer 26

Making use of the structural and functional differences between prokaryotic cells (them) and eukaryotic cells (us)

Question 27

Following translation, what modifications can occur for proteins?

Answer 27

GlycosylationPhosphorylationUbiquitination for misfolded proteins

Question 28

How is the function and localisation of a protein determined?

Answer 28

Structure and post-translational modification

Question 29

What is ubiquitin?

Answer 29

A small chemical moiety

Question 30

What happens in ubiquitination and why?

Answer 30

Proteins are degraded because they were misfolded.

Question 31

Many proteins in the nucleus contain what kind of signal?

Answer 31

Nuclear localisation signal

Question 32

In cases where there are not specific signals in the peptide sequence, how are proteins transported to the nucleus?

Answer 32

They are phosphorylated

Question 33

What signal do proteins secreted from the cell/ inserted into the plasma membrane have at their amino terminus?

Answer 33

ER/ endoplasmic reticulum signal sequence / peptide

Question 34

What is the location of protein modification?

Answer 34

Golgi Apparatus

Question 35

What is the contents of a nucleus?

Answer 35

Chromatin Nuclear Envelope Nuclear Pore Nucleolus

Question 36

What is the majority of a nucleolus made from?

Answer 36

RNA

Question 37

What is a nucleoplasm?

Answer 37

A nuclear substance containing chromatin and RNA.

Question 38

What is genetic polymorphism?

Answer 38

2 or more variants of an allele

Question 39

True or false? Most genes are polymorphic?

Answer 39

True

Question 40

List examples of point mutations in base sequences

Answer 40

Insertion | Deletion