genetic in medicine

Question 1

Longevity

Answer 1

• longevity is the duration of a person’s life
• homozygous recessive mutation can cause an individual to die young without acceleration of aging
• accident can also do the same
• Longevity is a polygenic trait: variation in genes and lifestyle choice contribute to it
• genetic contribute around 25-50%
• mutant in model organism is used to study longevity

Question 2

mutation in fly and longevity

Answer 2

-mutation of chico gene increase the longevity of fly

Question 3

life expectancy

Answer 3

-there is an increase in life expectancy when compare to the past-> importance of lifestyle

Question 4

ageing

Answer 4

• focus on senescence( physiological, physical and mental decline)
• intrest in the rate of senescene

Question 5

Theories of ageing

Answer 5

Genetic theory:
-genes we inherit from our parent code for our lifespan
-accumulation in damage to our somatic cell
Non genetic theory
-damage done to our body by free redicals
-changes in metabolism
-autoimmune theory (our immune system attack the body)

Question 6

Can we slow ageing

Answer 6

-dietary restriction have shown to increase the lifespan of many organism

Question 7

Cancer

Answer 7

A cancer is a clone of cells dividing in an unregulated way.
The dividing tissue invades normal body organs and disrupts their function
• sarcoma eg., bone • carcinoma eg., breast, bowel • haemopoeticand lymphoid malignancies eg., lymphoma, leukaemia

Question 8

Cell numbers

Answer 8

Cell numbers are kept constant in an adult by : 1. cell replication 2. cell death (apoptosis)
problem in these system can lead to cancer

Question 9

metastasizes

Answer 9

Cancer becomes a problem when it invades other tissues – metastasizes

Question 10

Cancer genes

Answer 10

Oncogenes –act in a dominant way (only need one mutation) Generally are changed proto-oncogenes
2.Tumour suppressor genes -block tumour development by regulating genes involved in cell growth -both alleles require inactivation to change this (act in a recessive way)

Question 11

Oncogenes

Answer 11

Ø We all have copies of proto-oncogenes – Ø genes are often involved in cell replication or cell death and kept in check (regulated) by other genes often tumour suppressor genes
Ø Activation of a proto-oncogene to become an oncogene can occur in a number of ways Ø Mutation –change in DNA sequence Ø Loss of regulation (control) by the tumour suppressor gene Ø Chromosome changes eg., a break and rejoin so proto-oncogene is in new place where it is activated

Question 12

Tumour Suppressor Genes (TSG)

Answer 12

Both copies have to be inactivated to loose their effect so recessive
Germ-line = mutation of TSG in a gamete (sperm or egg) so passed on to offspring
Somatic = mutation of TSG in a body cell –not passed on to children

Question 13

Cancer is a multi step process

Answer 13

At each stage a clone containing the previous mutation expands and makes a bigger target for subsequent mutations

Question 14

personalize medicine

Answer 14

-Not all individual of a particular illness react positively to a medicine
-The underlying cause could be different in individuals( needs to be understand for effective treatment)
-If we know who the responder is, the paitient will receive the best possible treatment and save money
-Aim to predict illness(even before birth)
ethical issues should patient know of the disease they have is incurable

Question 15

Problem with genome project in medicine

Answer 15

-There are different explanations for different people but some mutation consistency can be observe