What happens during meiosis that does NOT happen during mitosis?

In pea plants, purple flowers are dominant to white flowers. If one parent is heterozygous and the other parent is homozygous recessive, what percent of the offspring are expected to be purple?

Zach is conducting an experiment to observe which type of fertilizer will allow a plant to grow the tallest. He puts three plants in identical pots and places them in the same location. He waters the plants each day with the same amount of water. Then, Zach measures the plant growth and records his observations.

Which of these is the control group in Zach’s experiment?

In Mrs. Garza’s science class, the students are reading about research done on a group of birds on the endangered species list. The researcher is an animal behaviorist who studies bird behaviors using video recordings to identify clues as to why the population is decreasing. Mrs. Garza asked the class if this researcher’s method could be considered an acceptable and reliable technique to discover scientific knowledge. She had students get into groups, vote on whether the research is acceptable or unacceptable, and provide reasons for the decision.

Which student group provides a reason that correctly supports its vote?

A scientist uses a computer model to investigate how heat flow in Earth's mantle results in the motion of tectonic plates. Which of these statements describes a benefit of using a computer model to simulate interactions in Earth's layers?

A 9-kilometer-wide meteorite hit Earth 65 million years ago. Scientists have found a high concentration of iridium in the sedimentary clay layer from this time period. Iridium is very rare in Earth’s crust, but it is abundant in meteorites. Scientists believe this impact ended the Cretaceous Period and caused the dinosaur extinction. Which of these statements correctly describes whether this is a theory or a law and why?