Once a year or possibly for a physical when you are doing a sport or camp. Hope this helps!
Please note I can only make out some of this, so here's the answers I can see-
Answer #5:
Left atrium, right atrium, left ventricle, right ventricle.
Answer #10:
1.2-1.5 gallons.
Answer #8:
White blood cells fight and kill off diseases.
I'll add more as I get it
EDIT!
Answer #4:
They assist in clotting your blood
Answer #14:
O, B, A, AB.
Answer: Natural Errors
Explanation: Mutagens can erase parts of DNA that then replicate, but is not a mistake made in copying DNA so that's not it. UV Radiation distorts DNA, but is not necessarily a mistake made in copying it. Natural Errors are mutations made by cells when they copy base pairs and ineffectively or for some other reason mutate/do not create the correct DNA, and the failure of cells to correct this is a mutation. This is also known as an error in DNA replication
<span>affect a child's ability to learn and get along with others, some people think an ADHD child's behavior is caused by a lack of discipline, a chaotic family life, or even too much TV.</span>
