Which celestial body forms as a result of dust colliding with earth's atmosphere?

a meteor
b asteroid
c comet

The population of bacteria in a petri dish doubles every 40 seconds. the population of the bacteria is initially 400 organisms. what unit is most appropriate for the time at which the number of bacteria is 300? hour bacteria per hour second bacteria per second

What is the process of a new plant growing from its seed into a seedling? primary growth fertilization pollination germination

Is this mrna or rna need need the answer in a hurry