mao a and cancer

8/2/2019 MAO a and Cancer

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Genes and the Environment

Case Studies : MAO A and CancerLO : Explain how genes and the environment interact in

phenotypic expression with reference to MAO A and cancer.

STARTER

Completethe W/S


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Monoamines

A group of

neurotransmitters

Wide range offunctions in the

human brain and body

(a) Dopamine

(b) Noradrenaline

(c) Serotonin


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Monoamine Oxidase A (MAO A)

Enzyme

Breaks down

monoamines after used

in synaptic transmission

Abnormally high or low

levels of MAO A is

problematic


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Quick Questions (To Discuss)

1) If we make too much MAO A, how will that

affect monoamine levels?

2) If we make too little MAO A, how will thataffect monoamine levels?

3) If low levels of monoamines are said to cause

illness such as depression, what sort of

illnesses do you think high level of

monoamines may cause, and why?3mins


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Behavior & MAO A

Too much MAO A has

been linked to:

(a) Aggression(b)Addiction

(c) Risk Taking Behavior

(d)Criminality


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TASK

1. Watch video

2. Read the articles Whos vulnerable and

Runs in the family3. Answer the questions on the following slide


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VIDEO

http://www.youtube.com/watch?v=K3gfzfqEr

e0&feature=related

3.10min to 4.40min


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TASK

(A) What is the role of dopamine in the human body

and how does it cause addiction? (3)

(B) What factors, apart from dopamine levels, affect

addiction? (3)

(C) Using your knowledge from the AS course how may

the genes that make MAO A and the environment

interact to cause addiction? (4) Key Words to use

Hints: switch/trigger

Extension : Read HSW box on p193 and outline good

and poor features of the study


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TASK

Watch the video

Sequence the text on the next slide in order,

so it makes sense!


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Cancer

1. They divide rapidly to form a tumour.

2. Malignant tumours cause disruption of cell

function and even death.3. The tumour may the split up (metastasis)

and lodge elsewhere.

4. Cancer cells do not respond to normal cellgrowth mechanisms

5. When this occurs we can call the tumour

malignant.


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Cancer

1. Cancer cells do not respond to normal cell

growth mechanisms.

2. They divide rapidly to form a tumour.3. The tumour may the split up (metastasis)

and lodge elsewhere.

4. When this occurs we can call the tumourmalignant.

5. Malignant tumours cause disruption of cell

function and even death.


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What causes cancer?

Think about different types of cancer

- Cervical

- Breast

- Lung

- Skin

- Leukemia


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Mutations

Proto-oncogenes code for __________ which

control the cell ________.

If the gene _________ it is called a oncogene.

Oncogenes cause the cell cycle to be overly

stimulated, so excess ___________ occurs.

Mutations in tumour suppressor genes, which

halt the __________________, also cause excesscell growth.

The chances of a _____________occurring are

also increased by _________________ factors.


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Mutations

Proto-oncogenes code for proteins which control

the cell cycle.

If the gene mutates it is called a oncogene.

Oncogenes cause the cell cycle to be overly

stimulated, so excess growth occurs.

Mutations in tumour suppressor genes, which

halt the cell cycle, also cause excess cell growth.

The chances of a mutation occurring are also

increased by environmental factors.


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Skin Cancer

Watch video and focus on how melanoma

forms.

http://www.mayoclinic.com/health/melanoma/MM00657


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Role of the Environment


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TASK

Using the graph on p195;

(a) Describe the trends in both graphs (6)

(b) Explain why the second graph shows a causallink with the first graph and not just

correlation.(3)

(c) Suggest why there is a difference betweenmales and females. (2)

Extension : What controls need to be in place in

the study to make it valid? (3)


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Plenary

Answer the question with the person next to

you:

1. What is MAO A and how does the

environment affect its production? (2)

2. What is cancer and what does theenvironment increase the chance of

happening to cause it ? (2)


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Big Question

Which is more important in

expressing a phenotype,

Genes or the Environment?


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Reminders

Wednesday Coursework Due

Friday Topic 3 Assessment

mao a and cancer

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