Topic 7 - Modern Genetics

Question 1

What is a genome?

Answer 1

All of an organism’s DNA, including mitochondrial/chloroplast DNA.

Question 2

What is the purpose of polymerase chain reaction (PCR)?

Answer 2

To amplify DNA by making millions of copies of a given DNA sample.

Question 3

What are the steps involved in PCR?

Answer 3

1. Set up reaction mixture 2. Heat to 95°C to separate strands 3. Cool to 50-65°C for primer binding 4. Increase to 70°C for DNA polymerase action 5. Repeat cycle around 30 times.

Question 4

What is DNA sequencing used for?

Answer 4

To predict the amino acid sequence of proteins and determine links to genetically determined conditions.

Question 5

How are DNA fragments visualized in DNA sequencing?

Answer 5

Using high-resolution gel electrophoresis and UV light.

Question 6

What is DNA profiling?

Answer 6

A forensic technique used to identify criminals and test paternity.

Question 7

What are the steps in DNA profiling?

Answer 7

1. Cut DNA with restriction endonuclease 2. Separate fragments using gel electrophoresis 3. Add alkaline buffer and nylon filter 4. Compare ‘blots’ using gene probes.

Question 8

Define transcription factors.

Answer 8

Proteins that bind to DNA to regulate gene expression.

Question 9

What are promoter sequences?

Answer 9

Sequences found upstream of a gene that enable the binding of RNA polymerase.

Question 10

What is epigenetics?

Answer 10

Heritable and reversible modifications to DNA that do not involve changes to the nucleotide sequence.

Question 11

What is DNA methylation?

Answer 11

Addition of a methyl (CH3) group to a CpG site on DNA that prevents transcription.

Question 12

What are the two types of histone modification?

Answer 12

1. Acetylation 2. Methylation.

Question 13

What is the effect of acetylation on chromatin?

Answer 13

Activates chromatin and allows transcription.

Question 14

What is non-coding RNA (ncRNA)?

Answer 14

RNA that affects transcription or modifies the products of transcription.

Question 15

What is RNA splicing?

Answer 15

Post-transcriptional modification of mRNA that allows the production of different proteins from a single gene.

Question 16

Fill in the blank: Stem cells are ______ cells which have the ability to differentiate into many different cell types.

Answer 16

[undifferentiated]

Question 17

What are the types of stem cells?

Answer 17

1. Multipotent 2. Pluripotent 3. Totipotent.

Question 18

What are induced pluripotent stem cells (iPS cells)?

Answer 18

Adult stem cells that have been reprogrammed to become pluripotent.

Question 19

What is recombinant DNA?

Answer 19

DNA that includes genetic material from more than one organism.

Question 20

What is the role of a vector in gene technology?

Answer 20

To transfer genetic material into a host organism.

Question 21

What is a knockout mouse?

Answer 21

A mouse with one or more genes silenced to investigate gene function.

Question 22

Define transgenic plants.

Answer 22

Plants that contain genetic material from an unrelated organism.

Question 23

What is the purpose of using Agrobacterium tumefaciens in genetic modification?

Answer 23

To transfer bacterial genetic information directly to plant DNA.

Question 24

List some uses of transgenic plants.

Answer 24

• Flood resistance * Pesticide production * Herbicide resistance * Changing nutrient value.

Question 25

True or False: Ethical issues are associated with the use of stem cells.

Answer 25

True.

Question 26

What are some diseases that stem cells can potentially treat?

Answer 26

* Diabetes * Multiple sclerosis * Parkinson’s disease.

Question 27

Outline the steps of RNA Splicing

Answer 27

1. Gene is transcribed resulting in pre- mRNA (transcript of the whole gene) 2. All introns (non-coding regions) and some exons (coding) are removed 3. Remaining genes are joined together by enzyme complexes called spliceosomes 4. the same exons can be joined in a variety of ways to produce several different versions of mature functional RNA