Our energy supply comes mainly from fossil fuels, with nuclear power and renewable sources rounding out the mix. These sources originate mostly in our local star, the Sun. Electricity falls into its own category because it's an energy carrier and not a primary source.
Topsoil is the most fertile soil layer for plants.
C human selection is the answer hope this helps
Explanation:
The nucleus (plural, nuclei) houses the cell's genetic material, or DNA, and is also the site of synthesis for ribosomes, the cellular machines that assemble proteins. Inside the nucleus, chromatin (DNA wrapped around proteins, described further below) is stored in a gel-like substance called nucleoplasm.
Answer:
1.The pleural cavity aids optimal functioning of the lugs during breathing. It transmits movements of the chest wall to the lungs, particularly during heavy breathing. The closely approved chest wall transmits pressures to the visceral pleural surface and hence to the lung (10-19.
2.The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarge.
Explanation:
