Answer:
Chloroplast
Explanation:
Endosymbiosis theory explains the origin of chloroplast and mitochondria in the eukaryotic organisms.
When the pro-eukaryotes engulfed the blue-green algae or photosynthetic bacteria, these bacteria formed the symbiotic relationship with the pro-eukaryotes. These photosynthetic bacteria transformed into the chloroplast organelles of the eukaryotes which can capture the sunlight and use it in the synthesis of glucose molecules. These eukaryotic cells later formed the plant kingdom.
Thus, the chloroplast is the correct answer.
Coral reefs are built by coral polyps as they secrete layers of calcium carbonate beneath their bodies. And inside each coral poly lives single-celled algae called zooxanthellae. So basically in simplistic terms, coral polys create coral reefs and algae is in coral polys which also goes into coral reefs when they are made.
The chromosomes in the sex cells would be half the chromosomes in the body cells; so since each body cell has 40 <span>chromosomes and half of that is 20, there's your answer. It's B. 20</span>
Waters Lower density while in a solid form is due to how the hydrogen bonds are formed as it freezes, water molecules are apart compared to liquid water. The structure of ice makes it less dense than free flowing molecules in the liquid water, giving it the ability to float on water.