Non-disjunction and cancer

What are carcinogens?

Environmental factors that increase rate of malignant tumours if exposed for a prolonged period of time

What is the result of non-disjunction in a zygote at fertilisation?

1) Unexpected characteristics
2) Birth defects
3) Potential miscarriage

What is partial non-disjunction?

When part of chromosome doesn't separate correctly

How can we prevent cancers?

1) Reduce sun exposure
2) Legislation on harmful products
3) Diet that has insoluble fibre and low fat
4) Limit alcohol consumption

In meiosis 1, how does non-disjunction affect daughter cells?

4 affected due to homologous chromosomes separation

In meiosis 2, how does non-disjunction affect daughter cells?

2 affected due to chromatids separation

What does aneuploidy mean?

Abnormal number of chromosomes

What does nullploidy mean?

No chromosomes

What does triploidy mean?

Three chromosomes

How many chromosomes in monosomy?

45

How many chromosomes in trisomy?

47

What are some examples of non-disjunction?

1) Downs - trisomy 21
2) Patau - trisomy 13
3) Edwards - trisomy 18

Why does cancer happen?

Cell differentiation goes wrong

What is a tumour?

Abnormal mass in tissue, a result of uncontrolled cell division

Why do tumours appear as lumps and bumps?

Cells have not differentiated into same type as surrounding tissue

What does malignant mean?

Cancerous cells can spread to other parts of the body

What does metastasis mean?

Result in secondary cancers

What does benign mean?

Cells don't spread but will when grown and can place pressure on surrounding tissue

What are examples of carcinogens?

1) UV radiation
2) X-rays - causes mutations in DNA
3) Chemical - alcohol, tobacco, asbestos