Biochemistry Readiness Check II

Biochemistry Readiness Check II

Points:

44/67 1 Choose the correct coding strand (non-template) from this template

(non-coding) DNA: 5' ACG GTA 3'

(1/1 Points)

5' UAC CGU 3'

3' UAC CGU 5'

3' TAC CGT 5'

5' TAC CGT 3'

Correct! First, note that we are asked for a template/non-coding strand of DNA. DNA uses the base T where RNA uses the base U. Therefore, we can eliminate the two answers containing U because they must be RNA and we want DNA. Then, recall that any strands of nucleic acid that bind to each other (base pairing; A-T/U or C-G) must be each be running in opposite directions (antiparallel; a strand running 5'-->3 is bound to a strand running 3'-->5'). If any two strands of nucleic acid (for example 2 strands of DNA in a double helix) are complementary (A-T/U or C-G), the two strands must run IN OPPOSITE directions, 5'--->3' and 3'--->5'.2 If one strand of chromosome 2 has a DNA sequence that consists of

this: 5’ AAG CGG TAC GTA 3’, what will be the composition of the

complementary DNA strand? (Select all that apply) (1/1 Points)

5' TTC GCC ATG CAT 3'

3' TTC GCC ATG CAT 5'

Correct! All complementary base pairing must be antiparallel. The strand that is complementary to 5’ AAG CGG TAC GTA 3’ is 3' TTC GCC ATG CAT 5'. If we simply 'flip' the sequence, we get 5' TAC GTA CCG CTT 3'. Thus, both of these are the correct answers. 3' TTC GCC ATG CAT 5' 3' TTC GCC ATG CAT 5' 5’ AAG CGG TAC GTA 3’ 3' AAG CGG TAC GTA 5' is similar to the original sequence (5’ AAG CGG TAC GTA 3’), but its 5' and 3' ends are swapped.

5' TAC GTA CCG CTT 3'

Correct! All complementary base pairing must be antiparallel. The strand that is complementary to 5’ AAG CGG TAC GTA 3’ is 3' TTC GCC ATG CAT 5'. If we simply 'flip' the sequence, we get 5' TAC GTA CCG CTT 3'. Thus, both of these are the correct answers. 3' TTC GCC ATG CAT 5' 3' TTC GCC ATG CAT 5' 5’ AAG CGG TAC GTA 3’ 3' AAG CGG TAC GTA 5' is similar to the original sequence (5’ AAG CGG TAC GTA 3’), but its 5' and 3' ends are swapped.

3' AAG CGG TAC GTA 5'

5’ ATG TAC GGC GAA 3'

3

The following sequence is the coding strand of the collagen gene: 5’

ATG GCG TTC GAA 3’ What is the sequence of the corresponding mRNA?(1/1 Points)

3' ATG GCG TTC GAA 5'

5' AUG GCG UUC CUU 3'

5' AUG GCG UUC GAA 3'

Correct! The coding strand and the mRNA both go in the same direction, but do not both contain Ts.

5' UTG GCG TTC GUU 3'

4 Which ingredients/molecules are required to set up a polymerase chain reaction? Select all that apply.(1/1 Points) Amino Acids RNA nucleotides DNA polymerase Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA.DNA nucleotides Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA.Template DNA Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA.DNA Primers Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA

synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA.Ribosomes RNA Primers 5 Which of the following steps in PCR occurs first?(1/1 Points) Elongation Annealing Cycling Denaturation Correct! Denaturation separated the DNA strands. The DNA strands must be separated to expose the bases to which the primers will bind.6 Which statement accurately describes how a frameshift mutation affects a gene?(0/1 Points) It will change a single nucleotide in a mutant gene compared to the normal gene.Examples are missense, nonsense, and silent mutations.It will change the number of nucleotides in a mutant gene compared to the normal gene. Examples are missense, nonsense, and silent mutations.It will change a single nucleotide in a mutant gene compared to the normal gene.Examples are insertion and deletion mutations Incorrect. - If you chose ‘change a single nucleotide in a mutant gene compared to the normal gene. Examples are missense, nonsense, and silent mutations”, this is incorrect.This is the correct definition of Point Mutations. Background: Errors that change the number of nucleotides in a gene (insertion/deletion) are said to ‘shift’ the ‘reading frame’ from the correct groups of three basses to new groups. To visualize what a frameshift is, imagine you are given a string of letters and told to start at the beginning and read every group of three letters: CATDOGRATPIGAPE. You would get "cat dog rat pig ape". But if we add an extra letter, say CATDFOGRATPIGAPE, following our "read every group of three" rule, we would get "cat dfo gra tpi gap e". Shifting our 'reading frame' by adding one more letter completely changes what we read. This is similar to what happens with a frameshift mutation.It will change the number of nucleotides in a mutant gene compared to the normal gene. Examples are insertion and deletion mutations.7 If the coding DNA sequence of a normal gene is 5' GTC GCA TGG TGA 3', what kind of mutation would create the mutant gene sequence 5'

GTC GAC ATG GTG A 3'?

(1/1 Points) Silent mutation

Nonsense mutation Insertion mutation Correct! Background. An insertion mutation adds nucleotides to a gene and is a type of frameshift mutation, which changes the way the mRNA codons are read, changing the amino acid sequence. See Figure 1-19 in the Module 1 text for more information.Deletion mutation 8 This learning objective is now tested in a different WGU course than Biochemistry. Please select True.True Incorrect. Incomplete dominance produces a blended phenotype.False 9 This learning objective is now tested in a different WGU course than Biochemistry. Please select True.True Incorrect. The first generation contains unaffected parents having affected offspring, also known as carriers. Therefore, it must be recessive. Since only males are affected, it is X-linked recessive.False 10 This learning objective is now tested in a different WGU course than Biochemistry. Please select True.True Incorrect. Genetic changes result from alterations of the DNA sequence itself - such as mutations.False 11 The LEP gene codes for an anorexigenic hormone. Interestingly, breastfeeding has been shown to alter methylation of the promoter of this gene, leading to increased LEP expression. What is likely happening in response to breastfeeding?(0/1 Points) Breastfeeding increases the methylation of the promoter of the LEP gene, decreasing the spacing between nucleosomes.Breastfeeding decreases the methylation of the promoter of the LEP gene, increasing the spacing between nucleosomes.Breastfeeding decreases the methylation of the promoter of the LEP gene, decreasing the spacing between nucleosomes.Breastfeeding increases the methylation of the promoter of the LEP gene, and the tight packing of the DNA alters binding of RNA polymerase.