Red blood cells shed their nucleus and DNA after maturing, so they cannot code for amino acids, and in turn, protein
Explanation:
For question no 19
Force (F) = 20N
distance (d) = 5m
Work = F * d
= 20 * 5
= 100 J
Now
For question no 20
D. No matter how much force is applied the object must have motion for work to be done.
Ecology is how nature works and flows, without it everything would be messed up, such as food chains and how people would be ranked on natures list.
I think the answer should be B as well hope it helps
