Answer:
The mass number of an atom is its total number of protons and neutrons. Atoms of different elements usually have different mass numbers , but they can be the same. For example, the mass number of argon atoms and calcium atoms can both be 40.
Explanation:
It is found in the cytoplasm as a simple circle.
Aristotle is the father of biology
Answer:
B
Explanation:
The Earth is tilted 23.5 degrees on its vertical axis. During the northern hemisphere's spring and summer, the northern hemisphere is tilted towards the Sun.
Animals need other organisms to survive and plants only need sunlight and water