3. Suppose there are 5 x 106 E. coli cells in a transformation reaction and you plate them all out to plates containing ampicillin. After incubating the plate at 37 deg C for 18 hours you observe 500 colonies. What fraction of the cells were transformed in this experiment

1/10^4

Explanation:

Given that 500 colonies were observed on ampicillin plate after transformation. 1 colony represents 1 transformed bacteria because each colony is assumed to have grown from one single bacteria. Hence, 500 bacteria had transformed from 5*10^6 bacteria.

Fraction of cells that got transformed = (Number of cells that were transformed/ Number of total cells)

= 500/(5*10^6)

= 1/10^4

Hence, 1/10^4 cells were transformed in experiment.

a. by using fur or clothes to trap heat energy near the body

ans.

dna fingerprinting is defined as a process that determines the dna characteristics of an individual. these dna characteristics are unique among individuals as their fingerprints, so it is known as dna fingerprinting.

steps of dna fingerprinting includes extraction of dna from sample, amplification of dna, restriction digestion of amplified dna, and then analysis of dna by gel electrophoresis, respectively.

thus, the next step performed by the scientist is 'to cut the amplified dna (obtained by polymerase chain reaction) by restriction enzymes that cleave the dna into fragments and their analysis.'