The major function of the immune system is to protect the host from environmental agents such as microbes or chemicals, thereby preserving the integrity of the body. This is done by the recognition of self and response to non-self.
The sun's energy drives various processes on earth. One of these processes is photosynthesis in plants whereby light energy is converted into chemical energy by forming carbohydrates from carbon dioxide plus water, which is a process which usually gives off oxygen which animals need to breathe. Another process driven by the sun's energy could be evaporation of water into the air to form water vapour and clouds which then precipitate when cooled off over mountains so is involved in the water cycle.
Answer:
(a) 145 N
(B) 40 N
(c) 10 ropes
Explanation:
Mechanical advantage, where and are input and output force respectively
Since MA is given as 10 and input force is 1450 N
Therefore, the mover must use a force of 145 N
(b)
Since also and the is given as 4 m then
(c)
Literally, we need 10 rope segments to support the piano since we utilize the mechanical advantage
The blood vessels farthest from the heart must have valves.
The valves which are present in the blood vessels prevent the backflow of the blood back into the specific organ.
There are different valves present in the heart are:
- The tricuspid valve is situated between the right atrium and right ventricle.
- The pulmonary valve is between the right ventricle and the pulmonary artery.
- The mitral valve is between the left atrium and left ventricle.
- The aortic valve is between the left ventricle and the aorta.
Other vales which are present in the blood vessels are in leg. Leg veins do require the valves. If not present the blood will go back down into the feet because of the gravity. Thus there are various valves present in the leg veins.
Valves in veins are bicuspid, meaning they have two flap-like structures that regulate blood flow in the vein.
To know more about the Valves, refer to this link:
brainly.com/question/12926213
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