Answer:
bone marrow
Explanation:
These are the blood cell-forming adult stem cells found in bone marrow. Every type of blood cell in the bone marrow starts as a stem cell. Stem cells are immature cells that are able to make other blood cells that mature and function as needed. These cells are used in procedures such as bone marrow transplants.
Answer:
3=D
4=C
Explanation:
I think this is right.... Sorry if not!!
B. smiling when you are happy
This is not an action that is controlled by the process of homeostasis in the body. Homeostasis is the process which is responsible for regulating the the internal environment of the body.
for instance, you go to the bathroom when your kidneys want to eliminate excess water and other substances.
Your lungs need more air when you are exercising so homeostasis is responsible of seeing that you get enough of it.
and sweating when you are hot to remove excess heat from your body via sweat.
These are all involuntary actions controlled by the process of homeostasis.
Smiling is a voluntary action. you do not need to smile. and you can whenever you like and not when you don't.
I believe the answer to this question is D, I am not sure though.
C) Tectonic is not a type of plate boundary