What kinds of animal cells might have a lot of mitochondria present

Plants that have reproductive structures called cones are?

At which location in earth’s interior does the top density continue to increase as thickness decreases?

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