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.
A Beaker is a laboratory tool used to measure exact measurements of water
Answer:
C Water flowing downstream is held up in a reservoir behind a dam. Some water moves down channels through turbines connected to generators which produce electricity
Explanation:
Good explanation.
Answer:
B) meteorite sample
Explanation:
The age of the solar system, derived from the study of meteorites (thought to be the oldest accessible material around) is near 5 billion years; that of the Earth is taken as 4.6 billion years. The oldest rocks on Earth are dated as 3.8 billion years.
The method of virus transmission which results in a greater spread of disease is through airborne transmission