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.
Answer:
DNA to RNA to protein.
Explanation:
Central dogma in biology was given by Crick in 1957. The central dogma explains the flow of genetic information in the cells.
According to the central dogma, DNA can multiply and increase its number by the process of replication. The information from DNA is changes to RNA by the process of transcription. The expression of protein product expression occur from the RNA by the process of translation. Hence, the information travels from DNA to RNA to protein.
Thus, the correct answer is option (2).
The enzyme that breaks down H2O2 is called catalase.
Cell membrane is responsible