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A Level Biology > Topic 8A - Mutations And Gene Expression > Flashcards

Topic 8A - Mutations And Gene Expression Flashcards

1
Q

What are the additional 4 mutations?

A

Addition
Duplication
Inversion
Translocation

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2
Q

What is addition mutation?

A

One or more bases are added

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3
Q

What is a duplication mutation?

A

One or more bases are repeated

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4
Q

What is an inversion mutation?

A

A sequence of bases are inverted and put back into the DNA base sequence (reversed )

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5
Q

What is a translocation mutation?

A

A sequence of bases are moved from one location to another (can be somewhere on the same chromosome or a different chromosome)

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6
Q

What could a mutation lead to?

A

Change in the tertiary structure which leads to a change in the function of the protein

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7
Q

What are the 2 genes that control cell division?

A

Tumour suppressor genes
Proto-oncogenes

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8
Q

What is the function of tumour suppressor genes?

A

Slow down cell division

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9
Q

What happens if a mutation occurs in the tumour suppressor genes?

A

Gene will become inactive and the cells will divide uncontrollably resulting in a tumour

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10
Q

What is the function of the proto-oncogene?

A

Stimulates cell division by producing proteins that make cells divide

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11
Q

What happens if a mutation occurs in the proto-oncogene?

A

Gene can become overactive, this stimulates cell growth and leads to uncontrollable growth resulting in a tumour

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12
Q

What are the 2 types of tumours?

A

Malignant
Benign

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13
Q

Describe the characteristics of malignant tumours (3)

A

Cancerous
Grow rapidly and invade and destroy surrounding tissues
Can spread to other parts of the body

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14
Q

Describe the characteristics of benign tumours? (3)

A

Not cancerous
Grow slower and often covered in fibrous tissue that stops cells invading other tissues
Often harmless, but can causes blockages and put pressure on organs
Some benign tumours can become malignant

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15
Q

How do tumour cells differ from normal cells? (6)

A

Have a larger and darker nucleus
Have an irregular shape
Don’t produce all necessary proteins to function proper
Have different antigens on the surface
Don’t respond to growth regulating processes
Divide more frequently than normal cells

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16
Q

State 2 causes of tumour growth?

A

Abnormal methylation
Increased exposure to oestrogen

17
Q

How does hypomethylation affect proto-oncogenes?

A

Increases the production of proteins that encourage cell division

18
Q

How does hypermethylation affect tumour-suppressor genes?

A

Can’t be transcribed so the proteins they produce won’t be made

19
Q

How can cancer be prevented?

A

If a specific cancer-causing mutation is known, its possible to screen for the mutation

20
Q

How can cancer be treated?

A

Gene therapy - where faulty alleles are replaced by working alleles

21
Q

What are stem cells?

A

Unspecialised cells which can be differentiated

22
Q

What are the 4 types of stem cells?

A

Totipotent
Pluripotent
Multipotent
Unipotent

23
Q

How’s many types of cells can totipotent stem cells differentiate into?

24
Q

How many types of cells can pluripotent stem cells differentiate into?

A

Many cells

25
Q

How many types of cells can multi potent stem cells differentiate into?

A

Limited cells

26
Q

How many types of cells can unipotent stem cells differentiate into?

27
Q

Which part of the body contains many stem cells?

A

Bone marrow

28
Q

What are the 3 sources of stem cells?

A

Adult stem cells
Embryonic stem cells
Induced pluripotent stem cells

29
Q

Where are adult stem cells retrieved from?

A

Body tissues of an adult

30
Q

Where are embryonic stem cells found?

A

Obtained from the embryo at an early stage of development

31
Q

Where are induced pluripotent stem cells found?

A

These are created by scientists in labs

32
Q

What are some ethical issues with stem cells?

A
  • getting from embryos created via IVF raises ethical issues due to destruction of an embryo
  • some people say only stem cells from adult embryos should be used
33
Q

What are benefits of stem cell therapy? (3)

A

Can save many lives
Can be used to grow new tissue or an organ which the body won’t reject
Could improve the quality of life for many people

34
Q

What are transcription factors?

A

Proteins which control the transcription of genes

35
Q

What does RNAi stand for?

A

RNA interference

36
Q

What does miRNA stand for?

A

Micro interference RNA

37
Q

What does miRNA do? (3)

A

Binds to a protein complex
Creates RNA induced silencing complex
Prevents translation occuring

A Level Biology (20 decks)

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