A convection cell can be described as an area of which it's boundries can be stated where two substances either fluid or gas can move due to the temperature changes.
Temperature and density in a convection cell have a relationship which is inversely correlated meaning that if the temperature increases, the density decreases and the matter which has a higher temperature and also lower density moves towards the part with the greater density. The direction of travel of the warmer substance is upwards and vice versa.
The mantle of the earth or the atmospheric movements between the land and the sea can be given as examples to convection cells.
Land animals require more energy since they have to overcome greater inertia during locomotion. Land mammals have adopted many evolutionary mechanisms to support high energy demand.
Heart is four chambered instead of the usual two in aquatic animals like fishes. More number of divisions in heart increases the efficiency of blood circulation process which in turn increases the oxygen delivery rate to cells for producing more energy.
Land mammals also have developed lungs which increase the efficiency of gas exchange process which increases the output of respiration process.
In addition, land mammals also have a strong and developed musculoskeletal system which helps in locomotion.
Structural formulas identify where the atoms/bonds within a molecule are located. Therefore, the atoms need to be listed in order of appearance (left to right). This makes the best answer D.) HOCOOH.
