Which of the following statements regarding the movement of molecules across cell membranes is true?
A)In facilitated diffusion, a molecule is moved across a membrane against its
concentration gradient

B)Water molecules are commonly actively transported out of cells.

C)Three examples of passive transport are diffusion, facilitated diffusion, and osmosis.

D)Polar molecules generally diffuse more readily through the plasma membrane than do
nonpolar molecules of the same size.

Amylase is an enzyme found in the human digestive system. why do you think it was important to keep the enzyme temperature above 37 degrees celsius (98.6 degrees f)? describe what might happen if the temperature decreased by 10 degrees celsius.

Coat color in cats is determined by genes at several different loci. at one locus on the x chromosome, one allele (x ) encodes black fur and another allele (xo) encodes orange fur. females can be black (x x ), orange (xoxo), or a mixture of orange and black called tortoiseshell (x xo). males are either black (x y) or orange (xoy). bill has a female tortoiseshell cat named patches. one night, patches escapes from bill\'s house, spends the night out, and mates with a stray male. patches later gives birth to the following kittens: one orange male, one black male, two tortoiseshell females, and one orange female. what are the genotypes of patches, the stray male, and the kittens?

What are the doorways into and out of cells, attached to the membrane, and built in the rough er.