This invention made amputation much safer, which cut down on the number of people who died during the procedure

The correct answer is:  a tourniquet.

The tourniquets are tight straps around an arm or leg and tightened to stop bleeding, used to control arterial and venous blood flow. In the past, tourniquet are used to control bleeding during amputations. Now,  a tourniquet is used in surgeries to block arterial blood flow following and to minimize blood loss.

the answer is d (apex) good luck : ))

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.