Correct answer: B). With fewer contractions
The main function of a contractile vacuole is to maintain the sufficient amount of water in the protoplasm of the cell. For the freshwater amoeba contractile vacuole is needed to pump water and maintain a osmoregulation.
But when it is kept in sea water, more contraction is required to expel the water out of the cell in order to make the environment inside amoeba same as of sea water.
The answer is option A.
The Student identifies the test tube
that stops bubbling first contains the catalyst.
Because Catalyst is a substance which
increases the rate of reaction, and the reaction shows that when a product is
obtained bubbles formed.
<span>When the student added X, Y and Z to the
test tubes. The one which is a catalyst fastened the reaction.</span>
The RNA (ribonucleic acid) and the associated proteins forms the ribosomes. These ribosomes are the site of protein synthesis in a cell. Inside the stained cell nucleus, the nucleolus part of the cell can be seen. The nucleolus is the part where the all the ribosomes of the cell are assembled.
Hence, the answer is 'nucleolus'.
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.
