Cause and effect of mutation

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Slide 1

Cause and effect of mutation

L Mathias

Slide 2

What causes mutation

Spontaneous

Increases caused by environmental factors

UV light

X-rays

Benzene, formaldehyde, carbon tetrachloride

Slide 3

Gametic and somatic mutations

Gametic – testis of males, ovaries of females, inherited

Somatic – in normal body cells occuring beyond zygote formation, not inherited but may effect the person during their lifetime. Chimaeras

Slide 4

Mutagens and their effects

Ionising radiation – Nuc radiation, xrays, gamma rays (e.g. medical treatment) associated with development of cancers (e.g. leukaemia, thyroid cancer and skin cancer

Slide 5

Mutagens and their effects

Viruses and microorganisms – integrate into human chromosome, upset genes and can trigger cancer

Slide 6

Mutagens and their effects

Environmental poisons – Organic solvents such as formaldehyde, tobacco, coal tars, benzene, asbestos, some dyes

Slide 7

Mutagens and their effects

Alcohol and diet – High alcohol intake increase the risk of some cancers. Diet high in fat and those containing burned or highly preserved meat

Slide 8

The effect of muations

Not all are harmful

Survival advantage

Most common among bacteria and viruses but also seen in insects

If no selective pressure may remain in population

Slide 9

Harmful mutations

Cystic fibrosis and sickle cell anaemia

Disfunctional proteins

Albinism – caused by mutation in gene of enzyme pathway of melanin

Slide 10

Beneficial mutations

Bacteria – antibiotic resistance through mutation, transfer between bacterial species

Superbugs such as MRSA have arisen this way

RNA viruses – such as HIV – mutates it’s protein coat so that the host human is unable to make antibodies quick enough against it

Slide 11

Neutral mutations

Neither harmful or beneficial to the organism but may be important in an evolutionary sense