Answer:
A tissue
Explanation:
It's not a organism, it's not an organ system because it's not, and it's not an organ so it must be a tissue
Answer:
The outside of the bone consists of a layer of connective tissue called the periosteum. Additionally, the outer shell of the long bone is compact bone, then a deeper layer of cancellous bone (spongy bone) which contains in the medullary cavity the bone marrow.
<h2>Exchange of Gases in the lungs</h2>
Explanation:
- Gas exchange occurs by process of <u>diffusion.</u>
- Gas exchange occurs in sac like structures called <u> alveoli.</u>
- <u>Oxygen</u> diffuses from the alveolar sacs into the blood in the capillaries.
- <u>Carbon dioxide</u> diffuses from the blood in the capillaries into the alveolar sac .
As blood passes through the lungs, it picks up oxygen and gives up carbon dioxide simply by diffusion down partial pressure gradients between blood and Alveoli,.
The blood having returned from body is relatively low in oxygen and high in carbon dioxide. On the other hand the alveolar air has higher oxygen concentration and lower carbon dioxide concentration.
Thus, when venous blood flows through pulmonary capillaries, oxygen moves from alveoli into the capillaries while carbon dioxide flows from capillaries into the alveoli.
A token economy.
It basically means that rewards and punishment shape behavior of students.
Their outermost shell has the maximum number of electrons it can hold.
Elements only react with each other to gain electrons to complete their outermost shell. Since noble gases already have a complete outer shell, they're usually inactive.