Answer and Explanation:
Corals are translucid or white, but they look brightly colored because they host symbionts with colorful photosynthetic pigments
. They can host different organisms that live on and among them, giving place to an amazing ecosystem.
One of these organisms is the photosynthetic unicellular microalgae, called zooxanteles, that are colorful and provide nutrients to the coral.
Corals provide shelter and protection to the algae, while algae provide nitrogenated nutrients, sugars, and color to the corals. Algae can store nitrogen in their tissues as nitrogen-rich crystals, which are constantly provided to corals.
This symbiotic relation allows corals to grow in different environments that are poor in nitrogen or other nutrients, such as the tropical clear waters.
When changes in radiation, temperature, or salinity in water occur, corals react to these changes losing these algae and becoming translucid again.
<span>Rex imitates a dog. The lead soldier controls the robot by using simple commands like “stop”, “fetch” and “heel”. It is designed to help the soldiers on operations and missions where it accompanies the lead soldiers from a distance, using the developed technology and patented by IAI. </span>
Answer:
C
Explanation:
I am taking the test right now and it seems to be the most valid answer
The inferior vena cava brings deoxygenated blood back into the heart from the lower body. For comparison, the part that directs deoxygenated blood from the upper body is the superior vena cava.
