In the treated sample, human glioblastoma (brain cancer) cells were grown in tissue culture in the presence of inhibitor-producing umbilical cord stem cells. in contrast, control sample glioblastoma cells were grown in the absence of stem cells. to get a "snapshot" of the phase of the cell cycle each cell was in at the end of 72 hours, the cell samples were treated with a fluorescent chemical that binds to dna. next the samples were run through a flow cytometer, an instrument that records the fluorescence level of each cell. computer software then graphed the number of cells in each sample with a particular fluorescence level.

The correct option is C.  The treated glioblastoma cells were cultured in the presence of an inhibitor from umbilical cord stem cells, but the control cells were cultured without the

inhibitor.

Explanation:

Glioblastoma can be described as a kind of cancer or tumour of the brain. Astrocytes are the cells which cause this condition. Glioblastoma is one of the most deadliest kinds of cancer. As astrocytes have contact with numerous neurons from the body hence a cancer in these cells can be very toxic.

Scientists have been working hard to find a treatment for this type of cancer.

In the experiment described above, the scientists have found out that an inhibitor present in the umbilical cord cells can stop cancer cell proliferation. Hence, they have derived a test culture where the glioblastoma cells were treated with this inhibitor molecule. The control group glioblastoma cells were not treated with this inhibitor.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.