Lecture 23: Diabetes and Epigenetics

Question 1

What is insulin resistance?

Answer 1

-a decreased ability of some of the cells of the body to respond to insulin

Question 2

How is type 2 diabetes best treated?

Answer 2

-lifestyle changes; eat better, lose weight if you’re overweight, and become more physically active

Question 3

What is pre-diabetes?

Answer 3

-a condition in which blood sugar is high, but not high enough to be type 2 diabetes

Question 4

Downside of treating pre-diabetes?

Answer 4

• diagnosis leads to false positives

- doctors say people have pre-diabetes, but may never go on to developing actual diabetes

Question 5

Lamarck’s Theory of Evolution

Answer 5

• believed that organisms changed during life in order to better suit their environment (ex. giraffes stretched out their necks to reach leaves in tall trees)
• these certain characteristics of an organism are passed down to its offspring
• believed evolution happens based on a predetermined plan
• disproved; “fruits of an animal’s labor is not passed down to offspring”

Question 6

Darwin’s Theory of Evolution

Answer 6

• believed that the desires of animals have nothing to do with how they evolve
• believed that all organisms are different, even of the same species
• Survival of the Fittest; believed that those animals who did not suit their environment died off and the stronger ones went on to reproduce and make up more of that population with certain characteristics
• ex. elephants with shorter trunks died off because they couldn’t reach food while those with longer lived because they were better suited to their environment
• did not believe evolution happened according to a plan

Question 7

What Lamarck and Darwin both agreed on

Answer 7

• both thought life was constantly changing to adapt to its environment
• both thought organisms were related
• both thought life evolved from fewer/simpler organisms to many/more complex organisms

Question 8

Agouti Mice

Answer 8

• when agouti gene is completely unmethylated: fat, yellow mice, more prone to disease
• when agouti gene is methylated (normal): normal weight brown mice, low disease risk
• when yellow mouse fed a methylated diet, produced normal brown offspring
• when brown mouse fed an unmethylated diet, produced fat yellow offspring
• shows that the environment in the womb influences adult health; health determined not just by what we eat, but also what mother ate while pregnant

Question 9

Thrifty Phenotype Hypothesis

Answer 9

A pregnant woman can modify the development of her unborn child such that it will be prepared for survival in an environment in which resources are likely to be short, resulting in a thrifty phenotype.

Question 10

Epigenetics

Answer 10

the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself

Question 11

How are epigenetics and diabetes thought to be related?

Answer 11

-environmental factors are contributing to the rise of diabetes