In what kind of estate does ownership revert to the grantor of the estate if usage fails to conform to a stated condition in the grant?

The correct answer is a Fee simple defeasible estate.

Explanation:

A fee simple defeasible estate is a type of property that has some conditions attached to it. In case the conditions are not conformed the estate goes back to the grantor.

The holder of such an estate holds it as a fee simple subject to that condition. If the given condition is not met the estate either goes to the original grantor or to a third party.

first one

explanation:

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'