Which bacteria clade contains the greatest number of species?

Ascientist and her team counted 200 individual deer in an area of 10 square kilometers. what is the population density?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

This is a biological reaction due to a stimulus. i need this quickly !