B. Two protons and two neutrons
The correct answer is a nutrient runoff.
Nutrient runoff is a major reason for eutrophication of surface waters, in which extra amount of nutrients, generally phosphorus or nitrogen, instigate growth of algae. Sources of nutrient pollution involve surface runoff from pastures and farm fields, emissions from combustion, and discharges from septic tanks.
Why temperature affects heart rate in ectothermic organisms? If the temperature is within the optimal range for enzyme activity more ATP will be produced and the heart will beat faster due to increased metabolic activity and energy availability.
<u>Answer</u>:
The organic chemicals that helps cell membranes to conserve the internal fluids are phospholipids.
<u>Explanation</u>:
Phospholipids are used to form plasma membrane of the cell. Plasma membrane surrounds the cell contents like various cell organelles, nucleus, ribosomes and proteins. A phospholipid molecules is made up if a polar head containing a phosphate group and the two non-polar tails made of long chains of hydrocarbon of fatty acids.
The another name for plasma membrane is phospholipid bilayer. The polar head is hydrophilic that interactes with polar environment while facing outside the bilayer while the non-polar tail is hydrophobic in nature which makes the internal hydrophobic region of cell membrane which faces inside the bilayer.
D is the answer. A gene is a part of a chromosome.
