Cellular Genetics

Question 1

Aneuploidy

Answer 1

Irregular number of chromosomes

Question 2

Klinefelter syndrom

Answer 2

XXY, causes infertility and small testes

Question 3

Turner syndrom

Answer 3

X, not adolescent growth spurt

Question 4

XYY syndrome

Answer 4

Asymptomatic

Question 5

Autosomal recessive definition and example

Answer 5

Non XY and recessive allele Cystic fibrosis

Question 6

Autosomal dominant (e.g. huntington’s disease)

How genetics causes hungtinton’s disease

Answer 6

Dominant allele, Huntington’s disease

Huntington gene is a tandem repeat of CAG.

Tandem repeat polymorphism where there are more than 40 repeats increases the risks of huntington’s.

Question 7

X linked recessive definition and example

Answer 7

Recessive gene on X chromosome. Haemophilia A

Question 8

X linked dominant definition and example

Answer 8

Dominant gene on X chromosome

Question 9

Mitochondrial

Answer 9

I hire item via mitochondria

Question 10

G banding of chromosomes

Answer 10

Alternating light and dark band patterns on each chromosome pair

Question 11

3 components of DNA

Answer 11

Deoxyribose, nitrogen base, phosphate

Question 12

Enzyme that releases Supercoiled DNA for replication

Answer 12

Topoisomerase

Question 13

Enzyme that separates the two strands of DNA

Answer 13

Helicase

Question 14

Direction of DNA polymerase bases

Answer 14

5’ to 3’

Question 15

Enzyme that gets rid of DNA primers

Answer 15

Exonuclease

Question 16

DNA ligament role

Answer 16

Links Okazaki fragments

Question 17

How telomerase works and what it does

Answer 17

It adds repetition of DNA bases at the ends of chromosomes, to prevent the lost of coding DNA in replication

Question 18

What are Point mutations

Answer 18

When a single base is changed. Can be a silent mutation, where amino acid produced is the same, but can also be missense or nonsense mutation where amino acids. E.g. sickle cell anaemia (missense) or premature stop codon (nonsense).

Question 19

Large scale mutations

Answer 19

Inversions, deletions, duplications or translocations.

Question 20

Differences between eukaryotic and prokaryotic transcription and translation

Answer 20

Question 21

What are the 3 modifications made to post transcriptional RNA

Answer 21

Splicing: removal of introns

Polyadenylation: adding of adenyl (A) nucleotides to the 3 prime end,

caping: RNA caping on 5’ end by the addition of 7-methylguanosine (phosphate group)

Question 22

3 steps of prokaryotic transcription

Answer 22

Initiation (with sigma factor and RNA polymerase binding)

Elongation

Termination

Question 23

Change in AA in sickle cell anaemia and what this causes

Answer 23

GAG to GTG

Glutamate to valine

This causes additional intra and inter cellular interactions that cause aggregation of cells and the sickle shape

Question 24

Structure of t RNA (part that binds the AA and loops

Answer 24

Question 25

Mechanism that allows t-RNA to bind to more than 1 codon coding for the same AA. (e.g. GCC and GCA both code for guanine but only 1 tRNA for both

Answer 25

Wobble pairing

Question 26

molecules involved in termination of translation

Answer 26

Stop codon of mRNA presented to A site. Release factor (RF1 or RF2) binds. Hydrolysis of protein from tRNA. Ribosome complex is disassembled. Requires IF3 and Ribosomal recycling factor and GTP hydrolysis

Question 27

Restriction enzymes what they are and the different types of cuts they do

Answer 27

Can be Cohesive ends of blunt ends

Question 28

What is cDNA and how it is obtained

Answer 28

c (complementary) DNA is a DNA copy of the mRNA of a cell, created using the enzyme reverse transcriptase

Question 29

use of dideoxynucleotides in DNA sequencing

Answer 29

Dideoxynucleotides cannot bind to other nucleotides on their 3’ end because the OH present in normal deoxynucleotides is changed to an H. Hence, the lenght of the resulting copied polynucleotides can tell what the nucleotides are.

Question 30

Examples of structural variations of genome

Answer 30

deletions, additions, inversions…

Question 31

Hardy Weinberg Principle

Answer 31

That allele and genotype frequencies will remain the same cross generations if nothing big influences this.

Question 32

Heritability

Answer 32

The proportion of a phenotype that is due to genotype