Achef sprays antimicrobial cleaner on her counter top. at first the bacterial population declines significantly. however, even though she continues to spray in the following weeks, the number of bacteria begins to increase again. why did this happen?

Bacteria resistance

Explanation:

The antimicrobial cleaner contained certain product which most bacteria living on the counter top were sensitive to. This means, the product was effective and killed most of them. This is why the population declines significantly.

Yet, a few bacteria were already resistant to this product. This happens because of variability in their genome. Some bacteria have mutations in their DNA that confers them this advantage, by chance.

This few resistant bacteria will slowly start to grow again, while the chef continues to spray them, and therefore keeps selecting the resistant ones allowing their population to increase again.

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.  

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.