Answer:
silica
Explanation:
Diatoms are microscopic organisms. they have shell that is made from organic compounds and silica.Diatoms contain silica in their cell walls. This material is used industrially in the production of toothpastes, silver polishes, and swimming pool filters. Silica is used to remove stains and debris.
Answer:
C
there awasw a mass extinction of dinosaur species at the end of the Mesozoic.
Explanation:
C
Have A Great One!
Each mouse in the study has brown ears.
Answer:
they are Na+, K+ and Ca2+ ion channels.
Explanation:
Ionotropic acetylcholine receptors are also called nicotinic acetylcholine receptors because beside acetylcholine (Ch) they respond to nicotine. These receptors are primary receptors in muscle for motor nerve-muscle communication that controls muscle contraction.
Two molecules of ACh are required for receptor to open. Since the receptors are linked to ion channels, the channels open. Opening of the channel allows positively charged ions to move across it: sodium enters the cell and potassium exits.
