20. Which of the following bacteria is considered coliform? A. E. coli
B. Proteus​​​​​​​​​​​​​​​​​​​​​​​​​​ C. Salmonella
D. Shigella
21. The Enterotube is used to distinguish between:
A. Staphylococcus and Streptococcus
B. Proteus and Salmonella
C. Bacteria and Fungi
D. Antibiotic-resistant bacteria

22. What type of specimen is used to inoculate an Enterotube?
A. Throat swab
B. Stool
C. Urine
D. Blood
E. Sputum

23. Which bacteria gives positive test for urease when growing on urea broth?
A. Proteus
B. Enterobacter​​​​​​​​​​​​​​​​​​​​​​​ ​​​
C. Salmonella
D. Shigella

24. Which bacteria gives positive test for decarboxylase when growing on lysine broth?
A. Proteus
B. Enterobacter​​​​​​​​​​​​​​​​​​​​​​​ ​​​
C. Salmonella
D. Shigella

25. The Lethal Effect of UV light is specifically caused by
A. UV –A
B. UV-B
C. UV-C
D. Infrared

you are certainly talking about this picture:

a: is the label of the white square, it is showing the  replication fork, formed by helicase (d) ==> so it is the site of dna separation and replication 

b: is a new dna brand that is following directly the replication fork, so it is continuous ==> built continuously from 5' to 3

c: dna polymerase cannot replicate dna on its own, it needs the of their proteins, and one of them plays the role of a clamp which fixes  the dna with the dna template and increases  the processivity of the enzyme. ==>   stops polymerase from falling off the  template.

d: is the enzyme responsible for forming the replication fork (helicase) ==> unwinds and separates dna into two strands

e: is the delayed strand, it is built  in the opposite sense of the helicase, so dna will be built in fragments ==> built  fragments from 5' to 3 joins

and finally f: is the enzyme that builds  the new dna strand (dna polymerase) ==>   adds nucleotides to make a new dna helix.

credit: gradman555p98x9p

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both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.