C. 1/4
punnet square is used for probable outcome of a cross so a.
C. a natural resource that humans use to generate energy
Answer:
A
Explanation:
B) not all cells have a nucleus. For example, prokaryotes have no nucleus
C)Not all cells have a cell wall.(Animal cells don't)
D) not all cells have mitochondria (Prokaryotes don't)
A) all cells contain DNA, and DNA is all composed of adenine, thymine, guanine, and cytosine.
1) Plants and plankton use carbon in the atmosphere for photosynthesis (CO2 + H2O -> C6H12O8 + O2).
2) Animals eat the plankton and plants, or decomposers/detritivores break down decaying plant material. This releases carbon back into the atmosphere via cellular respiration.
3) Dead organisms are buried and become fossil fuels, burned for fuel because of its carbon content (this returns carbon to the atmosphere)