Globin 1 and globin 2 genes of insects are understood to have diverged approximately 170 million years ago, through duplication, from a common globin gene ancestor. The two genes that code for haemoglobin have conserved regions; oxygen-binding and heme- regions. Globin 2 gene has lost the intron region that is still present in the globin 1 gene. The percentage divergence is 7.2% with 20 varying nucleotides.

8 0

2 years ago

One g of fecal matter was suspended in 99 ml saline solution (tube 1). After mixing gently but thoroughly, one ml from tube 1 wa

malfutka [58]

Answer: the cfu/g Gram-negative bacteria in the fecal sample is C = 3.0 × 10^3

Explanation:

We know that; Gram negative bacteria looks pale reddish in color under a light microscope from Gram staining.

therefore

There are 30 red bacterial colonies counted.

1 mL of from tube 1 was removed and added to tube with 99 mL saline (tube 2) dilution is 1/100.

transferred volume into the plate is 1 mL.

Now, we have to determine the cfu/g Gram-negative bacteria in the fecal sample

Formula to calculate CFU/g bacteria in fecal sample is expressed as;

C = n/(s×d )

where C is concentration (CFU/g) , n is number of colonies , s is volume transferred to plate , d is dilution factor.

so we substitute

C = 30 / ((1/100) × 1)

C = 30 / 0.01

C = 3000

C = 3.0 × 10^3

THERFERE, the cfu/g Gram-negative bacteria in the fecal sample is C = 3.0 × 10^3

3 0

3 years ago