Low levels of in the brain have been linked to alzheimer's disease.

What’s this animal (picture is tagged) and where is it most likely to live, rainforest or desert?

What is the difference between sex-linked traits and autosomal traits in humans? a. sex-linked traits can only be passed from fathers to sons, while autosomal traits can be passed on from both parents to offspring of any sex. b. sex-linked traits are passed on through the x and y chromosomes, while autosomal traits are passed on through the other 22 chromosomes. c. sex-linked traits only affect females, while autosomal traits affect both males and females. d. sex-linked traits refer to genes that are on the x and y chromosomes, while autosomal traits refer to genes on all 23 chromosomes.

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine