1. which pair of bacteria can be differentiated by oxidase test? A. Pseudomonas and E. coli
B. Salmonella and Proteus
C. Proteus and E. coli
D. Shigella and Salmonella

2. Colonies of which color would you expect on HE agar if shigellosis is suspected?
A. Pink
B. Red with black center
C. Red without black center
D. Green with black center
E. Green without black center

3. Colonies of which color would you expect on HE agar if Enterococcus sp. is suspected?
A. Pink
B. Salmon/orange
C. Red with black centers
D. Green with black centers
E. None of the above

1. A. Pseudomonas and E. coli

2. B. Red without black center

3. B. Salmon/orange

Explanation:

Pseudomonas is referred to as an oxidase positive bacteria while E. Coli is an oxidase negative bacteria. The use of the oxidase test will be helpful in the differentiation of the two Bacteria according to their oxidase activity/properties.

Colonies of Red without black center color is what is expected on HE agar if shigellosis is suspected.

Colonies of Salmon/Orange color is what is expected on HE agar if Enterococcus sp. is suspected.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

the answers are as following:

1. c. double helix, nucleosome, coil, supercoil, chromosome

2. b. g2 phase, preparation for mitosis

3. d. interphase consists of the g1, s, and g2 phases

4. c. metaphase

5. a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set