When researching and developing new flu vaccines, what region of the world do scientists often look to? Why?

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

According to this food web which of the following would be considered primary consumers

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.