This because ice is less dense than water of particular temperature range. Water reaches its maximum density at 4 degrees. Ice is important especially for aquatic life in the polar regions. Polar bears give birth and hunt on sea ice and they need it to travel from one region to another. The ice edge in coastal areas is an important feeding ground for the walrus that uses the ice as diving platforms to feed on clams on the sea floor. Ice algae grow at the porous bottom of sea ice and form the base of the unique marine food web connected to sea ice
The organelle described above is called the endoplasmic reticulum. The rough portion of this called the granulated endoplasmic reticulum and the ribosomes attached to it enable it to produce proteins. The smooth portion of this organelle does not contain ribosomes and it has a role in the synthesis of lipids.
Explanation: The space in the center of the eyeball is filled with a clear jelly-like material called the vitreous humor. This material allows light to pass through to the retina. It also helps the eye keep its round shape.
