What invention was an early step in the discovery of cells

The appearance of the microscope was very important in the discovery of the cells. Robert Hooke built one that allowed him to expand the objects 50 times its size, so he observed a cork and could see several cells they  are dead plant cells.

the sphincter muscles at the end of the digestive tract is the anus.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.