Genetics and Health Week 1

Question 1

Define Gene

Answer 1

Length of DNA contains exons and introns which is then transcribed into a mature mRNA, and then finally translated into a protein

Question 2

Define Genome

Answer 2

Organism’s complete set of DNA

Sum of all genes

Question 3

Define Transcriptome

Answer 3

The total amount of mRNA that is expressed from the genes of the organism

Question 4

Define Proteome

Answer 4

Entire set of proteins that is expressed by an genome, tissue, organism

Question 5

Define Exome

Answer 5

Part of the genome that contains exons which codes for genes

Question 6

What is the purpose of the Francis Collins Approach?

Answer 6

Creating longer sequences of the chromosomes

Question 7

What is the purpose of Craig Venter Approach?

Answer 7

Breaking down the whole genome into pieces

Question 8

Define Each

1) Metacentric
2) Submetecentric
3) Acrocentric

Answer 8

1) Metacentric: Centromeres are located near the chromosome center
2) Submetacentric: Non-centrally located so that one arm is shorter
3) Acrocentric: are located near the end of a chromosome

Question 9

Explain the function of each type of Disease

1) Inherited Disease
2) Bacterial Infection
3) Viral Infection

Answer 9

1) Alter or eliminate normal gene function
2) Alter tissue function by producing proteins that interfere with normal cellular functions
3) Force the host genome to make viral proteins

Question 10

When do chromosomes start to appear?

Answer 10

M-phase

Question 11

What is the purpose of the cffDNA?

Answer 11

to determine the gender of the baby

Question 12

Define Telomere

Answer 12

region of short repetitive DNA sequences at the end of a chromosome

Question 13

Explain Euchromatin

a) Physical State
b) Type of Genes
c) Replicates During

Answer 13

a) More Relaxed
b) Active
c) Early S-phase

Question 14

Explain Heterochromatin

a) Physical State
b) Type of Genes
c) Replicates During

Answer 14

a) More Condensed
b) Slient
c) Late S-phase

Question 15

Chromosome Terminology

X (p or q)11.2

Answer 15

1) Chromosome
2) Arm
3) Region
4) Band
5) Sub-Band

Question 16

How to trace:

A) Maternal ancestry
B) Parental ancestry

Answer 16

A) Mitochondrial DNA

B) Y-chromosome

Question 17

Describe the Gene smear test

Answer 17

1) Taking blood sample and isolating red blood cells to analyse leukocytes.
2) Treat leukocytes with colchicine to inhibit mitosis (prevents them from progressing to anaphase).
3) PVut them on a slide to be viewed microscopically

Question 18

Describe the Chorionic Villus Sampling

Answer 18

Cells of the chorion are sampled at 11-14 weeks of gestation.

Question 19

Describe the Amniocentesis

Answer 19

Foetal cells suspended in the amniotic fluid around the foetus are sampled at 15-18 weeks of gestation.

Question 20

Describe Non-Invasive Prenatal testing

Answer 20

Analysing maternal blood sample which contains cell-free foetal DNA.

Question 21

Define Pluripotent Cell

Answer 21

A pluripotent cell is a stem cell that can differentiate into any type of cell (bone cell, muscle cell etc). Pluripotent cells contain a higher proportion of euchromatin as it is less committed to a specific function.

Question 22

Define Tay-Sachs Disease

Answer 22

Tay-Sachs disease is an autosomal recessive disease that is caused by inherited two copies of a mutated HEXA gene found on chromosome 15.

The mutated HEXA gene does not produce hexosaminidase A, which is responsible for breaking down a fatty material in the brain and nervous system called GM2 ganglioside

The build up of GM2 ganglioside results in neurological problems. Symptoms include loss of motor skills, movement problems and muscle weakness

Question 23

Describe the organisation of DNA in chromosomes using the terms: nucleotides, double helix, histones, nucleosomes and chromatin

Answer 23

Nucleotide base pairs bind to each other and create a double helix which wraps around a core of 8 proteins called a histones, forming a nucleosome. Nucleosomes condense to form chromatin