Answer:
Some don't because of many things, disease and not getting enough food.
Explanation:
I think its a and b, but i dont know what kind of rock it is. my guess is a metamorphic or sedimentary.
Answer:
Open populations occur when the total population is dynamic, with new members leaving and being added over time. ... Closed populations occur when the members of population are fixed and no new members are added or lost from the group (except through birth and death
Explanation:
hope this helps also dont fprget to thank me
Rbc dont have a nucleus to pack more haemoglobin. it also has a biconcave shape to increase surface area.... idk about the other two. sorry