Unit 3 Review

Question 1

What type of ends do restriction enzymes create when cutting DNA at specific sequences?

Answer 1

Can create either blunt or sticky ends depending on the cut location

Sticky ends have overhangs, while blunt ends have even cuts.

Question 2

What is the corresponding DNA strand for the original strand AAGCTT?

Answer 2

TTCGAA

Question 3

What type of cut does the restriction enzyme create at the sequence AAGCTT?

Answer 3

Sticky Ends

Question 4

What is the corresponding DNA strand for the original strand CAGCTG?

Answer 4

GTCGAC

Question 5

What type of cut does the restriction enzyme create at the sequence CAGCTG?

Answer 5

Blunt Ends

Question 6

What is the role of the guide RNA in the CRISPR Cas9 system?

Answer 6

Guides the system to the area of the DNA with a corresponding sequence

Question 7

What is the function of Cas9 in the CRISPR Cas9 system?

Answer 7

Endonuclease protein that makes cuts in the targeted DNA segment

Question 8

What types of cuts does the CRISPR/Cas9 system create?

Answer 8

Double-stranded cuts

Question 9

What is the difference between homologous directed repair and non-homologous end joining?

Answer 9

Homologous directed repair uses donor DNA to insert a new gene

Question 10

Is the gel configuration correct when the positive end is by the wells?

Answer 10

No

Question 11

What happens to DNA in a gel electrophoresis when the positive end is by the wells?

Answer 11

DNA will move towards the positively charged anode

Question 12

What are the required components of PCR?

Answer 12

• Template DNA
• DNA Polymerase (Taq polymerase)
• dNTPs
• DNA Primers

Question 13

If you start with a single DNA molecule and run a PCR for 12 rounds, how many copies will you have?

Answer 13

4096 copies

Question 14

If you start with a single DNA molecule and run a PCR for 30 rounds, how many copies will you have?

Answer 14

1,073,741,824 copies

Question 15

If you start with a single DNA molecule and run a PCR for 53 rounds, how many copies will you have?

Answer 15

9,007,199,254,740,992 copies

Question 16

What is the formula for calculating the number of DNA copies after PCR?

Answer 16

2^n, where n is the number of cycles

Question 17

In Sanger sequencing, which end of the gel corresponds to the 3’ end of the DNA?

Answer 17

The top of the gel

Question 18

Is the sequence seen on the Sanger sequencing gel the template strand?

Answer 18

No, it is the coding/corresponding strand

Question 19

In a Southdown sheep population, what are the observed genotype frequencies for AA, AS, and SS?

Answer 19

• f(AA): 0.595
• f(AS): 0.397
• f(SS): 0.008

Question 20

Is the Southdown sheep population in Hardy-Weinberg Equilibrium (HWE)?

Answer 20

No

Question 21

What is the frequency of the ‘g’ allele in a population of 1000 golfers where 60 are excellent golfers (gg), 440 average (Gg), and 500 true hackers (GG)?

Answer 21

0.28

Question 22

What is the frequency of the ‘G’ allele in the same population of golfers?

Answer 22

0.72

Question 23

What is the frequency of the Tay-Sachs allele in humans if 1 in 100,000 newborns are homozygous for the recessive allele?

Answer 23

0.003

Question 24

What is the frequency of heterozygotes for Tay-Sachs disease?

Answer 24

0.006

Question 25

What are the required calculations to determine the correlation between weight and height?

Answer 25

Calculate means, variances, and standard deviations

Question 26

What is the selection differential (SD)?

Answer 26

SD = Parent Mean – Population Mean ## Footnote In the context of the example, SD is calculated using the mean height of selected individuals and the mean height of the overall population.

Question 27

What is the formula for calculating the selection response (R)?

Answer 27

R = Progeny Mean – Population Mean ## Footnote This formula helps determine the difference in mean height between the progeny and the overall population.

Question 28

How is realized heritability (h²) calculated?

Answer 28

h² = R/SD ## Footnote This calculation gives an indication of the genetic contribution to the observed selection response.

Question 29

What was the mean height of the selected individuals in the horse breeding example?

Answer 29

48 inches ## Footnote This mean height was chosen from a population with a mean height of 60 inches.

Question 30

What was the mean height of the progeny in the horse breeding example?

Answer 30

55 inches ## Footnote This height indicates the outcome of the selection process applied to the selected individuals.

Question 31

What is the mean height of the overall population from which the selected individuals were chosen?

Answer 31

60 inches ## Footnote The overall population mean height serves as a baseline for calculating selection differential.

Question 32

What is the significance of a selection differential in quantitative genetics?

Answer 32

It measures the difference between the mean of selected individuals and the mean of the overall population ## Footnote A higher selection differential indicates stronger selection pressure on the trait of interest.

Question 33

True or False: Realized heritability can be greater than 1.

Answer 33

False ## Footnote Realized heritability values range from 0 to 1, indicating the proportion of phenotypic variance that is attributable to genetic variance.

Question 34

Fill in the blank: The selection response is calculated as the difference between the _______ and the population mean.

Answer 34

progeny mean

Question 35

What was the population mean height in the horse breeding example?

Answer 35

60 inches

Question 36

What does a realized heritability value of 0 indicate?

Answer 36

No genetic contribution to the selection response ## Footnote This means that any observed changes are due to environmental factors rather than genetic factors.