It seems that you forgot the answer choices, but lucky for you, I know the answer..
Answer: creating skin tissue by combining cells from different cell lines
Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
:)
Answer:
There are four main stages in the water cycle. They are evaporation, condensation, precipitation and collection. Let's look at each of these stages. Evaporation: This is when warmth from the sun causes water from oceans, lakes, streams, ice and soils to rise into the air and turn into water vapour (gas).
Explanation:
Testable and rejectable.
Recorded data may be quantitative or qualitative.
Answer:
D
Explanation:
Prokaryotic are simple cells and do not have nucleus.