A galaxy is a group of stars, interstellar gas, dust, etc.
There are different types of galaxies. They are all categorized by their shape:
Spiral: a spiral galaxy has a disc in the centre and curved arms that come out of it.
Irregular: it does not have a specific shape. It is just a mass of things.
Elliptical: an elliptical galaxy looks basically like a disc in the universe.
I hope it helps. I tried to explain it as easy and as simple as possible!
Explanation: Bacteria are needed in the nitrogen cycle because plants and animals cannot directly use atmospheric nitrogen. Bacteria in the roots of plants trap nitrogen and convert it to ammonia and other nitrogen compounds which plants can then use to make protein
The mass of an atom is contained in the nucleus.
Answer:
thylakoid membrane
Explanation:
The green pigment chlorophyll is located within the thylakoid membrane, and the space between the thylakoid and the chloroplast membranes is called the stroma