Answer:
B. Gravity held the pieces of forming planets together.
c. Gravity pulled most of the matter into the center of the solar system
D. Gravity caused the planets and Sun to have spherical shapes.
Explanation:
When a collection of grains pulled together by their gravitational forces would keep in by the gravity of a star, it would eventually became bigger to the point a planet was formed.
The sun's strong gravitational force pulled most of the matter around it to the center of the solar system.
The spherical shape of planets is a result of their gravity pulling equally from all sides, shaping it into a sphere.
The Sun is currently a main sequence star and will remain so for another 4-5 billion years. It will then expand and cool to become a red giant, after which it will shrink and heat up again to become a white dwarf. The white dwarf star will run out of nuclear fuel and slowly cool down over many billions of years.
- The reaction in which we can't take back the product to reactant form .Or in simple words the reaction which is irreversible is called chemical reaction
Example:-
We cannot pull back the reaction to get wax back .
The development of chloroplast is thought to occur through endosymbiosis.
According to the endosymbiosis, some of the organelles found in modern eukaryotic cells, such as mitochondria and chloroplasts, were previously prokaryotic microorganisms. A non-photosynthetic creature acquired one photosynthetic cell, and the chloroplast was subsequently created.
An organelle known as a chloroplast is crucial to the process of photosynthesis in plants. It contains pigments like chlorophyll and other pigments that are in charge of capturing sunlight. Since each chloroplast has two membranes, other organelles such as mitochondria are referred to as double-membrane organelles. It is believed that cyanobacterial endosymbiosis played a role in the genesis of the chloroplast. Prokaryotic organisms like cyanobacteria have the capacity to prepare their food through the process of photosynthesis.
Learn more about endosymbiosis here:
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