Lecture 26

Question 1

Chimps Skin colour

Answer 1

• light skin
• darkens with age
• protected by hair

Question 2

Skin colour is constitutive

Answer 2

natural skin colour without input from the environment

Question 3

Melanin

Answer 3

• gives dark colour to skin
• protects against UV radiation with its ability to prevent direct and indirect damage to DNA at wavelengths where it is most vulnerable

Question 4

Factors favouring dark skin

Answer 4

• cool ourselves through sweating

- melanin protects skin from uva and uvb damage

Question 5

Negatives of UVA

Answer 5

• breaks down folic acid

- folate deficiencies play a negative role for reproducing and developmental processes

Question 6

Things Vitamin D3 is necessary for

Answer 6

• necessary for efficient use of dietary calcium

- needed for proper growth of bones in vertebrates

Question 7

Shortage of D3 leads to

Answer 7

weakened bones
immune dysfunction
cancers

Question 8

what D3 is made from

Answer 8

• made from 7-dehydrocholestrol
• facilitated by UVB exposure
• melanin absorbs and scatters the UVB wavelengths that catalyze the synthesis of vitamin D3

Question 9

Conversion of 7-dehydrocholesterol to vitamin D is affected by

Answer 9

1. Increasing age
2. Clothing
3. Use of topical sunscreens

Question 10

Inuit Skin Colour

Answer 10

• dark skin colour
• recent immigration into the north
• eat a lot of fish and foods that are rich in vitamin D
• their skin and folate is protected because of the amount of vitamin D in their diet