All are aspects of antibiotics resistance in bacteria.
• overuse of antibiotics in humans
• bacteria can reproduce so quickly
• any use of antibiotics will select for resistant bacteria
• overuse of antibiotics in livestock
Answer:
zinc oxide is a pure substance
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
Answer:
Option B, Snakes and lizards share a common ancestor.
Explanation:
From the description provided, it is clear that both the lizard and snake (including pythons) have evolved from the same ancestors which had hind legs. Since both the organism (i.e lizard and snake) underwent evolution (differently) for million of years such that the hind legs in lizard are visible and used even today but the hind legs in snakes are buried in muscles toward their tail ends and are not used. Such features which are not used at all or are poorly used are called as vestigial organs.
Hence, option B is correct
