Which of the following statements regarding melanin is true? select one: a. during pregnancy melanin production is increased. b. both melanocytes and keratinocytes produce melanin. c. in addison's disease, less melanin is produced. d. men produce more melanin than women. e. melanin is a white pigment.

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine.what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.

Which of the following is the definition of ventilation as it relates to the respiratory system?

Alberta is a 20 year old who has been a vegetarian for 3 years. she comes to you for advice after reading some material online by the meat promoters of america organization. one of their statements is: ". . vegetarians are at risk for protein deficiency because they cannot consume all of the essential amino acids necessary for healthy individuals." how should alberta be advised? she should consume dairy and egg products at every meal to protect herself against protein deficiency she should avoid the "limiting" amino acids because they are limiting her ability to maintain proper protein status because the statement is basically true, she should consider eating small quantities of meat every day in order to avoid protein deficiency although many foods don't provide all the essential amino acids individually, she could consume complementary proteins throughout the day, which would provide all the essential amino acids she needs