Answer:
Water cycle is also known as the hydrological cycle. It involves the water in water bodies such as ocean, river, lakes etc being heated up by the sun and then evaporations into the atmosphere. The evaporated water then condenses and falls back as rain into the water bodies.
The water body is always low during summer due to the water being heated and evaporated into the atmosphere and high during spring/winter due to rainfall and less evaporation.
The hormone described above is the hormone Melatonin.
Melatonin is a hormone secreted by the pineal gland in the brain, which helps regulate other hormones and maintains the body's circadian rhythm. This rhythm is an internal 24 hour clock that plays a critical role when we fall asleep and when awake. When it is dark the body releases more melatonin.
Answer: Antibiotic Resistant Mutation
Explanation: Not all of the bacteria die because there are individuals in the population that have an antibiotic resistant mutation, which causes them to be adapted to dealing with the antibiotic. There will be a large population of bacteria again because the ones with the mutation survive, reproduce, and pass the antibiotic resistance trait on.