Tag Info

New answers tagged

0

You're right, the answer is b since the presence of oxygen would lead to aerobic respiration and not fermentation. If maltose was toxic, the yeast wouldn't grow. Proteins are required for growth, but the yeast is growing. Any temperature that is extreme enough to prevent fermentation would also prevent other cellular processes and the yeast wouldn't ...


14

This is an embryonic stem cell on the tip of a needle photographed on a scanning electron microscope (SEM). The image was taken by Steve Gschmeissner, see here for the original.


6

Lets start with the definition of a virus (from the Wikipedia page on viruses): A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to bacteria and archaea. So basically speaking you have a piece of genetic information (DNA or RNA) ...


4

In addition to Alan Boyd's answer of a macrophage, it could also be a T cell or B cell. Try doing an image search for lymphocyte SEM and browsing through the different cell types. While the traditional image of T and B cells has been of a smooth round blast cell, they actually have numerous projections, folds, etc. to aid in forming the immunological ...


4

This looks like a macrophage to me, which is a white blood cell. Try Googling "macrophage sem" to see similar images (SEM = scanning electron microscopy/micrograph). The clue is the nature of the cell surface - those ruffles reflect the macrophage's role in engulfing foreign material. Indeed it is possible that some of the particles on the surface are ...


1

Healthy plant growth depends on a microbial community that lives around and inside the roots of plants (Bais et al. 2001). Roots secrete from the roots a number of chemical compounds that influences the microbial community around but outside of the roots. The microbial community can include bacteria, fungi, and single-celled parasites, as well as larger ...


1

Since you have apparently tried to answer the question here is my interpretation. I list the six pictures (numbered from top to bottom) and link four of them to an answer. 1 - yeast cells? 2 - ash tree section (c) 3 - rotifer (b) 4 - muscle fibre?? 5 - bacteria? (a) 6 - Leeuwenhoek's microscope (d) According to the WP page on van Leeuwenhoek he did ...


2

Who said they did not have the same problems? I'm sure they did and I'm sure most of them had horrible diarrhea. A quick google search brought up Man and Microbes: Disease and Plagues in History and Modern Times, by Arno Karlen which states that In 1817, when the first cholera pandemic began [...]. In Calcutta and Jessore, cholera killed 5,000 British ...


2

Answer clarified based on comment by @DurgaDatta What would it mean to say the enzyme activity was tested in vitro on the mutant? When we say the response of the a single gene knock out mutant, the cell should be intact except for lacing one gene, which would mean that the response is in vivo. The knockouts were performed inside the E. coli cells and, ...


1

It is possible to conduct an in vitro experiment with cell extracts. Meaning that you break up the cells and put their pieces into a reaction glass and do your experiment. It is assumed that the cell molecules (enzyme, sugar or cofactors) will still carry out their functions even though the cell is no more. In other words, you used the mutant to produce the ...


1

I am assuming in spacesuit here, on the face (lit side) of the moon. Bodily degradation involves much more than external fungi and bacteria. Cells that receive no oxygen or nutrients die. We talk of such tissue death as dry gangrene when it affects extremities, such as fingers, feet, etc. However, we also recognize gangrenous bowel, etc. which results in ...


3

Decay is a process where the body is digested by bacteria, fungi and other living things. The moon has no known biological processes and while its possible for some microorganisms to survive in space, I think its generally understood that the lunar surface would not support life in a significant way, especially if the body is in vacuum. Other processes ...


2

I actually doubt that the pectinase has such a broad pH range in which it works optimally. Searching the web I found two figures which support my doubts: The first is from an article ("Immobilization of pectinase by adsorption on an alginate-coated chitin support") which compares the activity of native and immobilized pectinase under different ...



Top 50 recent answers are included