Question

all of them please

Question 12 (1 point) Which of the following conditions would kill amp' lac his bacteria? amp = ampicillin (an antibiotic), lac = lactose (a carbohydrate), his = histidine (an amino acid) A) growing the bacteria in media that contained ampicillin, had lactose as the sole metabolic carbon source, and contained the amino acid histidine. B) growing the bacteria in media that contained ampicillin, had lactose as the sole metabolic carbon source, but did not contain the amino acid histidine. C) growing the bacteria in media that did not contained ampicillin, had lactose as the sole metabolic carbon source, and contained the amino acid histidine. growing the bacteria in media that contained ampicillin, had lactose AND glucose as the sole metabolic carbon sources, and contained the amino acid histidine. D)

Answer 1

1) The given bacteria is amp^r, lac⁺ and his^-. What it technically means is that, the bacteria is resistant to ampicillin, an antibiotic, it has the ability to breakdown lactose when it is present as a sole carbon source in the media and that it cannot produce histidine (an important amino acid) and thus it has to be supplied in the media.

The question asks for the scenario where the bacteria is unable to survive. Let's look at the options one by one.

a) The media contains all the components, ampicillin, lactose and histidine. The bacteria will survive in this media.

b) The media contains ampicillin and lactose as sole carbon source. However it does not contain histidine. Since our bacteria is ampr, lac+and his-, it can easily tolerate both amp and lactose. However, being his-, it could not produce histidine and needed it to be suplemented by the media. Since the media does not have histidine, the bacteria will not survive.

The answer is thus: B

2) Translation, the process of conversion of mRNA to protein begins at AUG. Thus the first amino acid is always methonine. However methionine is not always retained after the process of translation is completed. The given sequence can be translated with the help of the chart given. Since the translation begins with AUG, the initial 3 nucleotides are not considered.

The sequence is:

5'- AUG GCC CGA GCA UUU CCG UAA UCA A-3'

The sequence has been split into groups of three to enable easy translation. The resulting amino acid sequence will be:

ala-arg-ala-phe-pro

AUG gets removed after translation, and UCA is the stop codon effectively terminating translation.

The answer is b

3) Replication: replicaation is the precess of duplication of DNA. DNAstrands undergoes unwinding and utilizing the parent strand as the template, makes another copy of itself. Thus replication is DNA to DNA.

Transcription: Transcription is process by which DNA sequence is utilized as a template to synthesize mRNA sequence. The resultign sequence is called a transcript. Thus transcription is DNA to RNA

Translation: Translation is a process by which the mRNA transcript is utilized to form amino acid chain known as polypeptide. Thus translation is RNA to polypeptide.

In order of occurance, it is: DNA to DNA, DNA to RNA and DNA to polypeptide.

The answer to the question is thus: B)