The earth rotates around its axis as it revolves around the sun. it takes the earth one year to complete a revolution.
The correct answer is option (D) Lipid molecules are nonpolar because they repel water molecules, which are polar.
Lipids are organic compounds made up of fatty acids and glycerol. A glycerol is a organic molecule with three hydroxyl groups and a fatty acid consists of a long hydrocarbon chain attached to a carboxyl group.
Lipids are hydrophobic, nonpolar molecules with no charge on their ends. Waxes are long chain nonpolar lipids. The water repelling property of the waxes prevent the water sticking to it and appear as water beads on its surface. The hydrophobic hydrocarbon tail of the fatty acids are hydrophobic in nature making them repel water. The presence of wax on the surface of the plants and animals protects them from dehydration.
Thus, the nonpolar property of lipids make it insoluble in the polar solvents like water as there is no interaction or sharing of electrons between them.
The statement above is TRUE. Puncture wounds refers to an injury that is caused by piercing of skin; a small hole is usually present. Puncture wounds do not usually bleed excessively but most times tissues and skin are crushed. Punctured wound can be superficial or deep.
The nucleus of the cell directs cell activity and acts like the control center. This is the place where gene activity is controlled in terms of the replication of the genes. In addition the movement and actions of the cell are also dictated from the nucleus.
Changes in groups of organisms over time produce variations in a population. This relates to both macroevolution and microevolution.
These are evolutions within a small group or a population and across the whole species.
