Answer:
A
Explanation:
I think its A but it can also be made to condense into a liquid
Single celled organisms such as amoebas, especially those that live in fresh water, continually gain water from their surrounding environment by osmosis. This water is pumped into a contractile vacuole which fills with fluid and periodically fuses with the cell membrane, releasing its contents to the exterior. Thus the amount of water actively transported out of the cell is equal to the amount of water entering the cell due to osmosis and there are no variations in the tonicity of the cell. This is homeostasis at a simple level. Without the contractile vacuole, the amoeba would continue to absorb water until its cytoplasmic contents were diluted to such an extent that metabolism no longer occurred and it would die.
In plants the endosperm is the structure that forms from a triploid nucleus and nourishes the seed when a plant undergoes double fertilization.
Answer: A variable within a scientific experiment is something that is changed (i.e. it varies). There should be only one manipulated variable within a scientific experiment so that the experimenter can be certain it is this variable which causes a pattern in the resultant data, if any exists at all.
Explanation:
Answer:
wouldnt that lead to a variation of the trait?
Explanation:
DNA is a double helix. It is composed of sugar, phosphates, and four different bases: A, T, G, and C. As cells grow, DNA is uncoiled and used to make proteins, but sometimes DNA is different between two bees (or humans) and then different proteins are made. These changes in the order of the A, T, G, C bases can be mutations or natural variations.
Substitution: This is usually just one base that has changed in the sequence.
Addition (insertion): One (or more) base added to the sequence. The surrounding sequence is the same after the insertion ends.
Deletion: One (or more) base is removed. The surrounding sequence is the same after the deletion.
