During phototropism, the plant hormone auxin<span> controls cell elongation.</span>
The difference<span> between the </span>birth rate<span> and the death </span>rate<span> of a country or place is called the </span>natural increase<span>. </span>
<span>In the middle archaeologists have uncovered many early human communities which were lost to time many ages ago, of these communities two notable ones are the Jericho and Catal Huyuk.</span>
Answer:
The polarity of membrane phospholipids
Explanation:
The inner core of membranes is made of nonpolar tails of phospholipids which in turn makes the membranes impermeable for polar, large and charged substances since these substances cannot cross the non-polar inner core. The saturated hydrocarbon tails pack tightly and make membrane less permeable while cholesterol affects the membrane permeability by interacting with non-polar tails.
Higher temperatures make the membrane more fluid and more permeable while at lower temperatures, membranes are more rigid due to tight packing of hydrocarbon tails and less permeable. The polar heads of phospholipids make the inner and outer surface of the membrane. Therefore, the polarity of phospholipids does not affect the membrane permeability.
