What did does it mean to draw a cell “to scale”?

What it means when they say draw "to scale" the size you draw has to be relative or similar to its actual size.

For example if you draw a 100-foot building with windows 5 ft high building and scale it down where 1 inch = 10 ft. The drawing of the building would be 10 inches tall with windows 0.5 in high.  

Since you are drawing a cell, it would be a bit different. When you select a size of the cell you will draw, the organelles should be sized or scaled to the size it would be if the cell were actually that big.

In other words, it should be proportion to the actual size of the cell.

If you look at the head face of a penny for example, you would see President Licoln's head scaled down to the size of a penny. The eyes and nose are proportioned to the size of the penny as well.

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.