Answer:
Explanation:
Cells generate energy from the controlled breakdown of food molecules. ... View Terms of Use molecules that other cells rely on for the energy required to sustain growth, metabolism, ... proteins that span the cell membrane permit specific molecules into the cell, Figure 2: Cells can incorporate nutrients by phagocytosis.
The correct answer is a - Lipid
Lipids are not considered as macromolecules because unlike proteins, carbohydrates and nucleic acids which polymers, lipids are composed of a single unit made up a glycerol backbone to which two or three fatty acids are linked.
Lipids are not polymers made up of individual subunits called monomers. They contain only one molecule and are not macromolecuels.
Examples of lipids include waxes, steroids, phospholipids and detergents. Lipids are generally hydrophobic and insoluble in water.
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
