Melanin is a skin pigmentation that absorbs and dissipates broadband UV rays. Since UV radiation causes DNA damage, melanin pigments protect the skin and reduce the risk of cancer. When skin is exposed to sunlight, melanin production is increased, causing the skin to tan. This demonstrates that

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 the environment causes mutations that increase the chance of survival

. the environment causes mutations that have a large effect on the chance of survival

the environment causes mutations that have no effect on the chance of survival

 the expression of some genes is influenced by the environment

 

A male and female have three children, all girls. The couple is expecting their fourth child. The probability their fourth child will be female is __i__, and the probability the couple will have four female children is __ii_. The row that indicates the correct probabilities is

Select one:

a.  i ii     

b.  i ii     

c.  i ii     

d.  i ii