1: Introduction to the human genome

Question 1

Genes and the ___ combine to create disease.

Answer 1

environment

Question 2

Strands of DNA pair up in a (parallel / antiparallel) fashion.

Answer 2

antiparallel

Question 3

DNA is read…

a) 3’ to 5’
b) 5’ to 3’

Answer 3

b) 5’ to 3’

Question 4

What is the sugar backbone of DNA called?

Answer 4

2-deoxyribose

Question 5

What is the sugar backbone of RNA called?

Answer 5

Ribose sugar

Question 6

What are the four bases of DNA?

Answer 6

ACGT

Question 7

What are the four bases of RNA?

Answer 7

ACGU

Question 8

The information in DNA is found in the ___ of base pairs.

Answer 8

sequence

Question 9

What are the base pairs of DNA?

Answer 9

A ⇔ T

C ⇔ G

Question 10

What are DNA strands wound into?

Which protein is involved?

Answer 10

Chromosomes

Histone

Question 11

How many bases are found in the human genome?

Answer 11

3 billion

Question 12

How many genes are found in the human genome?

Answer 12

30,000

Question 13

In which phase of the cell cycle does DNA replication occur?

Answer 13

S phase

Question 14

What occurs during the S phase of the cell cycle?

Answer 14

DNA replication

Question 15

___ mechanisms fix DNA damage which may occur during the S phase.

Answer 15

Repair

Question 16

Defects in DNA repair mechanisms can lead to ___.

Answer 16

disease

Question 17

What is cell division otherwise known as?

Answer 17

Mitosis

Question 18

What occurs during mitosis in terms of cell number?

Are the daughter cell(s) haploid or diploid?

Answer 18

One diploid parent cell divides into two genetically identical diploid daughter cells

Question 19

What occurs during meiosis in terms of cell number and ploidy number?

Answer 19

1 diploid parent cell becomes 4 haploid daughter cells

Question 20

Which process introduces variation during meiosis by swapping genes between chromosomes?

Answer 20

Crossing over

Question 21

Meiosis is the process behind ___ formation.

Answer 21

gamete

Question 22

In terms of strand number, what is the difference between DNA and RNA?

Answer 22

DNA is double stranded

RNA is single stranded

Question 23

DNA is ___ into pre-mRNA.

Pre-mRNA is ___ into mRNA.

mRNA is ___ into protein.

Answer 23

transcribed

spliced

translated

Question 24

DNA is transcribed into ___.

Answer 24

pre-mRNA

Question 25

**Pre-mRNA** is spliced into \_\_\_.

Answer 25

**mRNA**

Question 26

**mRNA** is translated into \_\_\_.

Answer 26

**protein**

Question 27

How many bases correspond to one amino acid (or a stop)?

Answer 27

**3**

Question 28

Every copy of the human genome is \_\_\_.

Answer 28

**different**

Question 29

What is a **polymorphism**?

Answer 29

Any variation in the human genome which appears in **\> 1%** of the population.

Question 30

What are the two components of a **karyotype** (e.g 46 XX)?

Answer 30

**46** - the total number of chromosomes **XX** - the sex chromosome complement

Question 31

**(Balanced / unbalanced****)** chromosome rearrangements are liable to cause disease.

Answer 31

**Unbalanced**

Question 32

What is **aneuploidy**?

Answer 32

**Having a whole extra or missing chromosome**

Question 33

What is a **Robertsonian translocation**?

Answer 33

When two **acrocentric chromosomes** become stuck end to end.

Question 34

What is the more **genetic** name for Down Syndrome?

Answer 34

**Trisomy 21**

Question 35

A Robertsonian translocation is likely to cause ___ - the cause of genetic disorders such as Down Syndrome.

Answer 35

**trisomy**

Question 36

Why is **X chromosome aneuploidy** (having one missing or one extra chromosome) better tolerated?

Answer 36

**Random X inactivation**

Question 37

What genetic disorder has the karyotype **45 X**?

Answer 37

**Turner syndrome**

Question 38

What genetic disorder has the karyotype **47 XXY**?

Answer 38

**Klinefelter syndrome**

Question 39

Other than **Robertsonian**, name a type of **translocation**.

Answer 39

**Reciprocal translocation**

Question 40

Most reciprocal translocations tend to be **(balanced / unbalanced****)**;

Answer 40

**balanced**

Question 41

What does **FISH** stand for?

Answer 41

**Fluoresence** in situ **Hybridisation**

Question 42

FISH allows you to detect individual ___ in genes using fluorescent probes.

Answer 42

**mutations**

Question 43

Which genetic test can be used to examine a whole genome?

Answer 43

**Microarray CGH**

Question 44

What are some consequences of unbalanced translocations in developing foetuses?

Answer 44

**Malformations** **Miscarriage**

Question 45

Different cells have different genetic make-ups and will proliferate in a patchy nature - what is this phenomenon called?

Answer 45

**Mosaicism**

Question 46

Somatic mosaicism for a chromosome abnormality is a genetic change which can contribute towards \_\_\_.

Answer 46

**cancer**

Question 47

Amplification of the HER2 gene is associated with which disease? How can it be treated?

Answer 47

**Breast cancer** **HER2+ breast cancer can be treated using HERCEPTIN (trastuzumab), a monoclonal antibody which targets it specifically**

Question 48

An abnormality in chromosome 22 (**Philadelphia chromosome**) can cause which disease? How can it be treated?

Answer 48

**Acute myeloid leukaemia** **AML** **can be treated using IMATINIB, a monoclonal antibody which targets cells which express BCR-ABL, the protein produced as a result of a Philadelphia chromosome translocation**