There are differences between Eukaryotic and Prokaryotic cells. This difference is considered to be the most important distinction between groups of organisms.
A Prokaryotic cell does not contain a nucleus. It only contains one chromosome and is a single-celled organism. It was the only form of life on earth for millions of years. Examples of a Prokaryotic cell are the different types of bacteria present today.
A Eukaryotic cell contains a nucleus; more than one chromosome and is typically a multi-celled organism. <span>Both plant and animal cells are eukaryotic cells.
</span>
I’m positive that the answer is B
Answer:
Here are the correct order of events that show evolution of the universe:
- Inflation
- Separation of last two fundamental forces
- Formation of subatomic particles
- Nucleosynthesis
- Formation of first stars
Explanation:
According to big bang theory, there were series of events carried on that lead to the formation of stars in the universe.
- Inflation was the time when universe began to expand at extremely fast pace.The dimensions of that old universe during the fraction of a second expanded by a factor of at-least 10^26 to 10 cm. Elementary particles like quark began to expand into the thin layer of universe.
- A strong nuclear force separated from its other two forces and the interactions between already created particles lead to the formation of more particles like Higgs bosons, W and Z etc.
- When the universe began to cool down below 10 quadrillion degrees, neutrinos, electrons and quarks began to form. Antiquarks and quarks annihilated with each other in a process called baryogenesis, this lead to the formation of matter.
- When the universe began to cool down below a billion degrees, the atomic nuclei begin to form when neutrons and protons combined by fusion reactions. The initially created nuclei were of simplest elements like helium, hydrogen and lithium.
- The period between the formation of first stars and atoms is called as dark age because there were no stars at that time. The formation of stars and galaxies was made 300 - 500 million years later. When the universe was kept expanding, gas pockets and gases became more and more dense. The small gas particles were collapsed under own gravity and became so hot that fusion reactions were triggered in them. Fusion between hydrogen atoms was the reaction which lead to the formation of most primitive stars.
