Bio Exam 2

During DNA replication in a cell, RNA primase synthesizes a primer that is complementary to the region in the sequence shown in bold:

5’ GUUGUAGGUUUC 3’

Why would a loss of function in the helicase cause an issue?

If there’s no helicase the strands won’t unzip and no new DNA can be made

Why would the loss of function of RNA primase cause an issue?

Without primase laying down a primer DNA polymerase can’t add any DNA nucleotides because it builds off the primer

Why would the loss of function of DNA polymerase cause an issue?

DNA Polymerase is the enzyme that actually adds the DNA nucleotides, without it no nucleotides can be added

Which of these is necessary for the first step of PCR

original template DNA

A new nucleotide can only be added to the _____ end of a growing DNA strand, DNA therefore only grows in the ___ to ___ direction.

3’ 5’ to 3’

A template DNA strand contains the sequence 3’ ATGCTGAC 5’. This strand is transcribed:

from left to right

You obtain three samples of nucleic acid and would like to determine each sample’s chemical identity (single stranded or double stranded DNA or RNA). You analyze the base composition of each sample and get the following results, with the numbers indicating the percentage of each base in the strand.
What conclusion can you come to about the nature of these samples?

Sample 1 is double stranded DNA and sample 2 is RNA an sample 3 is single stranded DNA

Shown here is a portion of the final mRNA sequence .

mRNA 5’ CCAUGUUCGAAUGGCUUG 3’

Which sequence is from the corresponding DNA template strand?

5’ CAAGCCATTCGAACATGG 3’

Muscle cells make different proteins than nerve cells because they have different sequences of DNA

false

In this figure, the item labeled “X” is _____ and it is synthesized by the process called_____.

RNA transcription

In prokaryotes, the processes of transcription and translation are said to be coupled, which means that:

they are connected in space and time

Binding sites for tRNA are located in:

the large ribosomal subunit

Assuming A-U and G-C pairing between the anticodon and the codon, what anticodon in tRNA would pair with the codon 5’ AUG 3’

5’ CAU 3’

Which of the processes occur in the cytoplasm of eukaryotic cells?

translation only

Classify mutations in the gene encoding beta globin in the figure:

missense

The most frequent kind of mutation, a point mutation, occurs when:

a single base pair is replaced by another