What is deppression and what cause it?-_-

Exercise has no positive effects on the nervous system? true or falseu

[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.

Polydactyly is expressed when an individual has extra fingers and/or toes. assume that a man with six fingers on each hand and six toes on each foot marries a woman with a normal number of digits. having extra digits is caused by a dominant allele. the couple has a son with normal hands and feet, but the couple's second child has extra digits. what is the probability that their next child will have polydactyly? polydactyly is expressed when an individual has extra fingers and/or toes. assume that a man with six fingers on each hand and six toes on each foot marries a woman with a normal number of digits. having extra digits is caused by a dominant allele. the couple has a son with normal hands and feet, but the couple's second child has extra digits. what is the probability that their next child will have polydactyly? 1/8 1/32 3/4 7/16 1/2