topic 7 PMT flashcards

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 PCR?

Answer 2

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

Question 3

What are the five main stages of PCR?

Answer 3

1. Mix DNA sample, primers, free nucleotides, and heat-stable DNA polymerase.

Question 4

2. Heat to 95°C to break hydrogen bonds and separate DNA strands.

Question 5

3. Cool to 50–65°C for primers to anneal.

Question 6

4. Increase to 70°C for DNA polymerase to build strands.

Question 7

5. Repeat ~30 times to amplify DNA.

Question 8

How is DNA sequencing used in genetics?

Answer 8

To predict amino acid sequences of proteins and determine links to genetic conditions.

Question 9

What are terminator nucleotides used for?

Answer 9

To stop DNA replication at specific bases during sequencing. They are fluorescently labelled.

Question 10

How are DNA fragments separated by size?

Answer 10

Using high-resolution gel electrophoresis.

Question 11

What is DNA profiling used for?

Answer 11

To identify criminals and test paternity.

Question 12

What enzyme is used to cut DNA for profiling?

Answer 12

Restriction endonuclease.

Question 13

What is the purpose of gel electrophoresis?

Answer 13

To separate DNA fragments by size using an electric current.

Question 14

What is a Southern Blot?

Answer 14

A method to transfer DNA fragments to a filter and identify them with gene probes.

Question 15

What are transcription factors?

Answer 15

Proteins that bind to DNA to regulate transcription.

Question 16

What is DNA methylation?

Answer 16

Addition of CH3 to CpG sites to repress transcription.

Question 17

What is histone acetylation and methylation?

Answer 17

Acetylation activates chromatin; methylation may activate or deactivate depending on lysine position.

Question 18

What is non-coding RNA (ncRNA)?

Answer 18

RNA that regulates transcription or modifies products, e.g. X-inactivation.

Question 19

What is RNA splicing?

Answer 19

Modification of mRNA where introns and some exons are removed to form functional RNA.

Question 20

What are the three main types of stem cells?

Answer 20

1. Multipotent

Question 21

2. Pluripotent

Question 22

3. Totipotent

Question 23

What is the ethical issue with embryonic stem cells?

Answer 23

Embryos are destroyed during extraction, raising moral concerns.

Question 24

What are induced pluripotent stem cells (iPSCs)?

Answer 24

Adult cells reprogrammed to become pluripotent, avoiding ethical issues.

Question 25

What is recombinant DNA?

Answer 25

DNA that includes genes from more than one organism.

Question 26

How can plasmids be used in genetic engineering?

Answer 26

Genes are inserted into plasmids which act as vectors to transfer DNA.

Question 27

Name some methods of gene transfer.

Answer 27

Gene guns, viruses, liposome wrapping, microinjection.

Question 28

What is a gene marker?

Answer 28

A gene used to identify if a gene has been successfully inserted (e.g. fluorescence, antibiotic resistance).

Question 29

What are knockout mice?

Answer 29

Mice with genes silenced to study gene function or disease models.

Question 30

How are transgenic plants made using Agrobacterium tumefaciens?

Answer 30

Ti plasmid is modified and used to infect plant cells, which grow with the inserted gene.

Question 31

Give three uses of transgenic plants.

Answer 31

1. Flood resistance

Question 32

2. Pesticide production

Question 33

3. Nutrient modification (e.g. soya oil improvement)