The relationship between the hermit crabs and the snails is A.commensalism
Why? Commensalism refers to a relationship where one organism benefits from the other without affecting it. In this case, the hermit crab benefits from the snails, via the latter's discarded shells. The crab's use of the snails' shells has no impact on the snails.
Plate boundaries are the edges where two points meet.
I think the answer would be A , break the darkness period with a flash of light for some time so that the plants can bloom all year round.
Answer: B) are excited by light that falls in the center of their receptive field.
Explanation:
There are two types of bipolar cells present in the retina which are differentiated on the way the centres of their receptive fields respond to light. The names of bipolar cells are ON-centre and OFF-centre.
If a light fall at the centre of the receptive field of a bipolar cell, it will experience an exciting effect on that cell, resulting in it being depolarized, it is an ON-center cell.
Hence, the correct option is B.
For many of their illnesses scientist and doctors haven't treated them before so they don't know how to treat them or exactly if the animal can handle the treatment