Can someone explain this thing i have test tomorrow but still i don't get the !

People with one sickle cell allele are not likely to get malaria. what is this an example of?

Been sitting here trying to take this test and don't know this answer! place the events of a feedback mechanism associated with body temperature in the correct order. ·nerve cells send message from skin to the brain ·body returned to normal temperature around 98.6 degrees f ·temperatures regulation center in the brain sends out signals ·body temperature exceeds 98.6 degrees f ·sweat glands throughout the body activate to cool off skin surface it is a 1 through 5 question in biology!

Has magnification ability of hundreds of thousands of times