Definitely true, because it is in a constricted space and you end up breathing more of it in, causing more harmful effects than if you were smoking the cigarette yourself
Answer:
Physical and chemical weathering often happen at the same time, but the ... Water that freezes in cracks and forms ice, salt from evaporated seawater, ... For example, the rocks on a riverbed smooth each other because they collide in the current. ... Oxidation is the reaction of oxygen with chemicals in a rock.
Explanation:
Answer:
Mutation
Explanation:
A mutation is a change in the sequence of genetic letters, called bases, within a molecule of DNA.
In photosynthesis, solar energy is harvested as chemical energy in a process that converts water and carbon dioxide to glucose. Oxygen is released as a byproduct. In cellular respiration, oxygen is used to break down glucose, releasing chemical energy and heat in the process.
Answer:
Calcium
Explanation:
Parathyroid hormone (PTH) is a hormone that is secreted by the parathyroid gland. It is the major regulator of the plasma concentration of calcium ions. It regulates calcium ions in the kidney, intestine and bones.
In the kidney, is involved in the re-absorption of calcium in distal ducts and the renal collecting duct, it is also involved in activating the conversion of 25-hydroxy vitamin D into 1,25-dihydroxy vitamin D (calcitriol).
In the intestine, PTH is involved in the absorption of calcium, by increasing vitamin D production.
In the bone, it helps in regulating calcium levels; when serum calcium level is low, PTH stimulates the activity of the osteoclast, to produce more calcium.
