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.
All isotopes of hydrogen will always contain one proton, as a change in the amount of protons will change the substance. Assuming all isotopes aren’t ions and therefore don’t have a charge, then each of these isotopes has one electron. The only difference between them is the amount of neutrons to account for the different atomic masses.
H1
one proton
one electron
zero neutrons
H2
one proton
one electron
one neutron
H3
one proton
one electron
two neutron
Clouds can block light and heat from the Sun, making Earth's temperature cooler. You've probably noticed this kind of cooldown on a cloudy day. However, some heat from the Sun does get down to Earth. Clouds can trap that heat from the Sun.
Answer:
depending on conditions !
Explanation:
e.g a peat bog or somewhere like the north pole vs a humid jungle or hot desert
things to consider
air composition in the environment to feed microbes
temperature to speed up reactions
any natural catalysts
PH of your environment
Stem cells. Or more specifically, embryonic stem cells.