In humans, having freckles is dominant over not having freckles. A heterozygous male with freckles has children with a female who does not have freckles. What fraction/percent of the children will not have freckles?

50%

Explanation:

If you do out the punnet square Ffxff, the result will be 50% of offspring with heterozygous (dominant trait is shown) and 50% will be homozygous recessive

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.