Answer:
D. There is no enough oxygen in the culture fluid
Explanation:
The cells in the test tube need to carryout one of the important metabolic processes of living organisms - respiration. The process involves the breakdown of glucose to generate energy for other metabolic processes in the cell.
Respiration can be carried out in the presence of oxygen (aerobic) or in the absence of oxygen (anaerobic). Human cells are primarily aerobic but can carryout respiration anaerobically in the presence of inadequate oxygen.
For aerobic respiration, glucose is broken down in the presence of oxygen to produce carbon-dioxide, water and energy in the form of ATP:

<em>In the absence of oxygen, the glucose becomes converted to lactic acid and a smaller amount of ATP is produced as compared to aerobic respiration.</em>
<em>Hence, lactic acid gradually builds up in the absence of oxygen due to anaerobic respiration.</em>
The correct option is D.
This phenomenon can be explained by Allen's rule. It says that the body proportions and shape may vary in different climates. The temperature decreases as the latitude increases, so in the northern region is much colder. Animals must preserve heat in such conditions. So, exposed surface areas of the body, such as the ears, feet, and tail, are usually minimized to minimize heat loss in the cold climate. <span>Therefore, northern species often have smaller ears, feet, and tail than the southern species. </span>
Answer:
Its been used by humans to take the best traits from a species and pass them on like bigger bodies in cows for more meat and bigger muscles in horses for faster racing potential.
Answer:
Temperature is the measure of the average energy of motion of all the particles present in a substance because particles of a substance moves due to the presence of kinetic energy.
Explanation:
Kinetic energy is a type of energy that is present in an object due to its motion. When temperature of a substance is increased, the particles absorb heat energy from surrounding environment and starts motion. This motion of particles due to the absorption of heat energy is called kinetic energy. So that's why temperature is considered as a tool to measure average energy of a motion.