What acceleration clause requires the borrower to pay off the entire mortgage debt when the property is sold?

commercial mortgages and residential mortgages.

Explanation:

An accelerated clause is a term in a loan agreement that requires the borrower to pay off the loan immediately under certain conditions. An accelerated clause is typically invoked when the borrower materially breaches the loan agreement.  For example, mortgages typically have an acceleration clause that is triggered if the borrower misses too many payments. Acceleration clauses most often appear in commercial mortgages and residential mortgages. They also appear in some leases. When a lender invokes an acceleration clause, the borrower must immediately pay the unpaid balance of the loan’s principal, as well as any interest that accumulated before the lender invoked the acceleration clause. The borrower does not, however, have to pay the full amount of interest that would have come due had the loan been paid off normally. For example, most loans allow the borrower to accelerate the loan and pay off the loan early in a single lump sum to avoid paying interest for the remainder of the loan’s term.

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.'