Question

1a. What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?

a. the orgins of replication occur only at the 5' end

b. DNA ligase works only in the 3'->5' direction

c. helicases are single stranded binding proteins work at the 5' end

d. DNA polymerase can join new nucleotides only to the 3' end and of a preexisted strand, and the strand are antiparallel.

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1b. DNA polymerase;

a. do not require a primer

b. add complementary base pairs to the only to the leading strand

c. synthesize DNA in both directions by creating a peptide bond between complementary base pairs

d. are produced through transcription and translation.

e. syntheisze DNA in the 3'to 5' direction.

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1c. Select the statement that accurately describes the differences between DNA replication in prokaryotes and eukaryotes.

a. Elongation rate is slower in prokaryotic than eukaryotic, because eukaryotic cells contain more enzymes that expediate the process.

b. Prokaryotic chromosomes have a single orgin of replication, whereas eukaryotic chromosomes may vary

c. prokaryotic chromosomes do not contain exons, but eukaryotic chromosomes do contain exons.

d. elongation rate is slower in prokayotic than eukaryotic, because prokaryotic cells have shorter chromosomes; therefore more Okazaki fragments the require additional processing

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1d. Prokaryotes are able to simitaneosuly transcribe and translate DNA, unlike eukaryotes. What is the best explanation?

a. Prokaryotes DNA is not bounded by a nuclear envelope.

b. Eukaryotes ribsomes are larger resulting in a slower reading of mRNA.

c. Eukaryotes require rRNA, but prokayotes do not.

d. Prokaryotes can complete the process with few enzymes.

i really do need explanation but just the asnwer so I can compare it. thank you and ill upvote

Answer 1

1a. The correct option is d. DNA polymerase can join new nucleotides only to the 3' end and of a preexisted strand, and the strand are antiparallel.

Explanation: The replication is continuous in leading strand whereas the replication is discontinuous in lagging strand where the DNA polymerase lag behind because it is unable to replicate both at same time.

​​​​​​1b. The correct option is b. add complementary base pairs to the only to the leading strand.

Explanation: DNA polymerase work only in one direction and add the base pairs to only 3' end of growing DNA i.e. the leading strand, which results in the DNA synthesis in 5' to 3' direction.

Other option are incorrect because DNA polymerase require primer, synthsesizes DNA only in one direction, synthesize DNA in 5' to 3' direction.

1c. The correct option is b. Prokaryotic chromosomes have a single orgin of replication, whereas eukaryotic chromosomes may vary.

Explanation: The prokaryotic cells has only one point of origin whereas the eukaryotic cells have multiple points of origin. The replication in prokaryotic cells occur in two opposite direction at same time that takes place in cytoplasm. The replication in eukaryotic cells is unidirectional in the nucleus of cell.

1d. The correct option is a. Prokaryotes DNA is not bounded by a nuclear envelope.

Explanation: Prokaryotes has no nucleus which separates the process of transcription and translation. Thus, when the bacterial genes are trancribed after this the transcripts begin to immediately translate themselves. The transcription process occur in cytoplasm alongside the translation process and that's why both occur simultaneously, which is not possible in eukaryotes. Because transcription occur in nucleus and translation occur in cytoplasm in the eukaryotic cells.