If a boy exhibits a sex-linked trait that is carried on the x chromosome, what must be true?
a. his mother exhibited that trait.
b. his father exhibited that trait.
c. his father’s mother carried an allele for that trait.
d. his mother carried at least one allele for that trait.

"His mother carried at least one allele for that trait" is the one among the following choices given in the question that is true. The correct option among all the options that are given in the question is the fourth option or option "D". I hope that this is the answer that has actually come to your desired help.

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.