The environment and gene expressions

Question 1

what is skin colour

Answer 1

it’s a polygenic trait as many genes contribute to the skin colour. There is continuous variation in the skin trait

Question 2

what does your skin colour depend on?

Answer 2

melanin

Question 3

what makes melanin?

Answer 3

melanocytes which are special cells located in the lower parts of the epidermis

Question 4

what do melanocytes produce

Answer 4

they produce structures called melanosomes that contain melanin

Question 5

what is the role of tyrosine

Answer 5

it is an amino acid which melanin is made from

Question 6

does everyone have the same amount of tyrosine?

Answer 6

yes

Question 7

does everyone have the same amount of melanosomes?

Answer 7

no, it varies

people with dark skin have more melanosomes which indicate they contain more melanin

Question 8

how are melanocytes distributed in the skin?

Answer 8

they are evenly distributed

Question 9

what does tyrosinase the enzyme do?

Answer 9

brings out the production of melanin

the darker the skin the more enzyme you have in the body

Question 10

what stimulates the activity of tyrosinase?

Answer 10

sunlight and UV rays