A Negative stain such as India ink or Congo red-Look for the presence of a capsule.
This stain method is usually used to stain the area around the microorganism.
B The Gram stain-Divide bacteria into two groups based on cell wall structure (thick vs. thin).
This is type of differential staining used to distinguish organisms based on their staining properties. Gram + and Gram- bacteria stain different because of different cell wall structure.
C The Ziehl-Neelsen Acid-fast stain- Identify bacteria with waxy cell walls such as: Mycobacterium tuberculosis (the cause of TB).
This is also differential staining method which uses heat and phenol to derive dye into the cells with lipid-rich walls.
D Simple stain with a basic dye-Stain microbes a bright color to make it easier to see them in bright field microscopy.
One dye is used in simple staining in order to determinate the size, shape and arrangement of the cells.
E The Schaeffer-Fulton Endospore stain-Identify Bacillus or Clostridium species, such as the causative agents of anthrax, botulism, tetanus and gangrene.
This is a special type of staining only used for the bacteria that can form endospores. Bacteria are first treated with heat and then with malachite green, which is very strong stain that can penetrate endospores.
Answer: B
Explanation:
During polymerization of nucleotides to form nucleic acids, the hydroxyl group on the phosphate group attaches to the 3’ carbon of a sugar of one nucleotide to form an ester bond to the phosphate of another nucleotide. The reaction forms a phosphodiester linkage and eliminates a water molecule.
The DNA strands generally runs from 5 prime to 3 prime direction.
<span>As humans change the way we live on the planet, the way that nitrogen moves around the Earth also changes. Nitrogen atoms may seem small enough to be easily overlooked. We look right through the ones in the air, do we not? Yet recent changes in the nitrogen cycle are causing a very noticeable effect on natural environments and human health. Lakes are clogged with aquatic weeds. Dead zones have formed in areas of the oceans where animals can not survive. Air pollutants that contain nitrogen are decreasing air quality and greenhouse gases that contain nitrogen are becoming more common.</span>
Las Ciencias de la Tierra o Geociencias conciernen y engloban las disciplinas que estudian la estructura, morfología, evolución, y dinámica del planeta Tierra. Constituye un caso particular de las ciencias planetarias, que se ocupan ellas del estudio de los planetas del Sistema Solar.
