Answer:
Positive feedback system increases temperature of the earth surface which is good in a number of ways.
Explanation: For example, due to increase in the temperature of earth surface, melting of ice occurs in the mountainous area of the world. This stored form of water is changed into liquid form and flows down through streams and used by plants and animals. But more increase in temperature causes rise of sea level which is not good for areas near the sea.
A. the cell theory stating that all living things are composed of cells.
Hope this helps!
-Payshence
Answer:
The statement is true
Explanation:
Hematopoietic stem cells give rise to myeloid progenitor and lymphoid progenitor and these two progenitors give rise to many immune cells. Dendritic cells are produced by both the progenitors and macrophages are produced by myeloid progenitor.
Both macrophages and dendritic cells are phagocytes. In phagocytosis, the foreing particles are injected by these phagocytes and they are destryoyed by the action of digestive enzymes present in these phagocytic cells.
Macrophages are present in tissue and if they are present in blood they are called monocytes. Therefore the statement is true.
Answer:
The activity of cyclic AMP phosphodiesterase is prevented by caffeine. The caffeine prevents further dissociation of cAMP, which eventually increases the response within the body. The activity of neurotransmitters, that is, of noradrenaline or epinephrine, gets increased due to enhancement in response.
This further enhances the activity of the heart, the rate of muscle contractions, blood pressure that further helps in delivering more oxygen to the brain, and other parts of the body. Thus, the inhibition of the enzyme cyclic AMP phosphodiesterase helps the athletes to prevent the wall.
