Answer:
50%
Explanation:
Let the allele for red-green color blindness be represented by c.
Normal vision woman whose father is color-blind will be 
Color-blind male will be 
x
Progeny: 
(See the attached image)
<em>Out of the 2 male progeny, 1 is affected for color-blindness while the other is not affected. This gives a 50% probability that a son of the couple will be color-blind.</em>
DNA was found to contain only four different chemical building blocks.
Thymine, is the answer you’re looking for.
Answer:
When the molecules are too large.
Explanation:
Facilitated diffusion refers to the passive transport of substances down the concentration gradient via specific transport proteins present in the membrane. The large, polar, charged substances and ions cannot pass through the small spaces present between hydrophobic tails of membrane phospholipids. The transport proteins transport these substances in energy independent manner.
