Which of the following statements best repesents the growth of the bacteria in nutrient agar

The answer is ; Bacteria growth entered the stationary phase after 3 hours

The bacterial growth is logistical – meaning it is represented by an S- curve. After the exponential phase where the bacterial population doubles with each generation, the stationary phase is reached. In this phase, the bacteria growth rate equals the death rate. The reduced growth rate is due to competition for resources between individuals of the population.  

it has one origin of replication, but it proceeds in two directions - d)

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.