First Quarter Moon is the second primary phase. First Quarter Moon is the second primary Moon phase and it is defined as the moment the Moon has reached the first quarter of its orbit around Earth, hence the name. It is also called Half Moon as we can see exactly 50% of the Moon's surface illuminated.
<span>The biggest difference between prokaryotes and eukaryotes is that eukaryote has a nucleus. They also have other membrane structures called organelles.</span>
