Which characteristic best explains why carbon is relevant to living organisms?"
Carbon is the most common element on Earth
Carbon can form a wide variety of molecules
Many carbon isotopes are radioactive
Many carbon allotropes occur in nature.

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

What is the average speed of a car that traveled 300.0 miles in 5.5 hours

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled