Mutations And Genes (Miss Reynolds)

Question 1

Mutation

Answer 1

A change to the nucleotide sequence of DNA.

Question 2

Mutagenic agent

Answer 2

Increase rate of mutations (above normal)

Question 3

When do most mutations occur and why?

Answer 3

Interphase, longest stage

Question 4

Substitution

Answer 4

One base is swapped for another

Question 5

Addition

Answer 5

An extra base is added

Question 6

Deletion

Answer 6

A base is removed

Question 7

Which types of mutation cause a frame shift?

Answer 7

Addition and Deletion

Question 8

Inversion

Answer 8

A sequence of bases is repeated.

Question 9

Duplication

Answer 9

One or more bases repeated.

Question 10

Tumour suppressor genes

Answer 10

Slow cell division.

Question 11

Proto-oncogenes

Answer 11

Stimulate cell division.

Question 12

When are proto-oncogenes switched on?

Answer 12

When growth factors bind to protein receptors on the cell surface membrane.

Question 13

Oncogenes

Answer 13

Permanently switched on, even in the absence of growth factors, caused by a mutation.

Question 14

Benign tumour

Answer 14

Not cancerous, slower growth, don’t invade other tissues and are most of the time harmless.

Question 15

Malignant tumours

Answer 15

Uncontrolled growth / rapid, cancerous, can spread to other tissues

Question 16

What does oestrogen cause in terms of cell division?

Answer 16

Increased cell division

Question 17

Stem Cells

Answer 17

Can divide and differentiate to become different types of cell. Can divide for all of the organisms lifetime.

Question 18

Induced pluripotent stem cells

Answer 18

Treating unipotent stem cells with transcription factors that make them pluripotent.

Question 19

How do you create induced pluripotent stem cells?

Answer 19

A modified virus as a vector inserts transcription factor genes from pluripotent cells into Dna of unipotent stem cells.

Question 20

What type of stem cells are adult and embryonic stem cells?

Answer 20

Embryonic - pluripotent, adult - multi-potent

Question 21

How can stem cells be used in medicine?

Answer 21

Replace faulty/damaged cells, to grow new organs which have the same antibodies so no rejections/donors needed.

Question 22

Ethical issues of stem cells

Answer 22

Taking them from embryos kills them, right to life.m

Question 23

Genetics

Answer 23

Study of biological processes and phenotypes and their functional molecules.

Question 24

Genome

Answer 24

All genes present in a species.

Question 25

Epigenetics

Answer 25

Study of stable cellular and physiological traits.

Question 26

Benefits of human genome project

Answer 26

Better and early diagnosis of disease, control systems for drugs.

Question 27

PCR

Answer 27

A technique used to amplify one sample of DNA thousands of times over to create a large enough sample for extensive analysis.

Question 28

Uses of PCR

Answer 28

Paternity, tests, detecting mutations and DNA profiling.

Question 29

Gene Therapy

Answer 29

Replacing genes with healthy ones.

Question 30

Somatic gene therapy

Answer 30

Copies of the corrected gene are inserted directly in to cells of sufferer. Does not prevent the disease occurring in the next generation and has to be repeated many times as effects do not last.

Question 31

Germ line therapy

Answer 31

The corrected gene is inserted into a fertilised egg produced via IVF, permanent but currently illegal.

Question 32

How is cystic fibrosis treated with gene therapy?

Answer 32

A vector is introduced to the correct gene into cells of the lung.

Question 33

What is cystic fibrosis caused by?

Answer 33

Mutant recessive alleles.

Question 34

Problems with gene therapy

Answer 34

Limited success due to liposomes not being small enough and adenoviruses causing infection, also patients have to undergo multiple rounds as effects are short lived.

Question 35

Summary of gene therapy

Answer 35

Identify gene responsible for disorder, make copies of normal gene by PCR, insert copies into vectors, infect affected cells with vectors and activate the healthy gene.

Question 36

DNA probes

Answer 36

Short single stranded section of DNA that has some sort of label attached to it.

Question 37

Uses of DNA probes

Answer 37

- Genetic counselling (identifying carriers of a disease and most effective treatment) - Genetic screening (parents can see if they are carriers of specific alleles, diagnose + treat before symptoms show)

Question 38

Genetic fingerprinting

Answer 38

DNA of every individual is unique.

Question 39

Uses of genetic fingerprinting

Answer 39

Solving medical problems (i.e paternity tests), gauging genetic diversity.

Question 40

Methylation effects

Answer 40

More methylation - terminates transcription.

Question 41

Acetylation of histones effects

Answer 41

Less acetylation of histones - terminates transcription.

Question 42

DNA interference

Answer 42

Controlling gene expression by preventing transcription.