Answer all the question fast....
Dear Student,
- Plasma membrane is called selective membrane or semi-membrane because it does not allow just every particle that come along to pass the cell membrane. It is a phospholipid bilayer with the proteins embedded in it, which allows water (solvent) to pass through but not the solute molecules. The solute particles passes through the protein, which permits only the useful solute particle to pass through.
- Seeds must not be planted deep in the soil because while germination, the seeds require O2 which will not be accessible under the thick layer of the soil. Also, the growth of the hypocotyl and epicotyl is affected under the pressure of the soil.
- Ileum is the largest part of the small intestine and thus provide larger surface area for absorption of food. In addition, presence of villi on the inner layer furthers improves the surface area for better absorption. It is congested tubular structure in which digested food moves slowly thereby providing time for complete absorption.
- Water is important part of our diet because it is essential for all the physiological, metabolic and biochemical activities of the body. It provides proper nutrient supply, helps in excretion, hydrate the cells of the body required for cellular activities, turgidity to the skin cells, etc.
- Because flies around are the carriers of many diseases like cholera, amoebic dysentery, etc. When our food is spoiled by these flies we are infected by these diseases. So, eating places must be clean of flies.