Final Exam More Review Questions

Question 1

Part of your blood type is determined by the gene that codes for the ABO blood groups. Within the ABO blood group, A and B are codominant with each other and O is recessive to both A and B. A mother with type O blood has a child with a father with type AB blood. Which of the following is false, based on this information?

a
The mother is homozygous recessive

b
This combination of parents cannot produce children with the AB blood type

c
This combination of parents cannot produce children with the O blood type

d
Approximately 50% of their children will have type A blood

Answer 1

a
The mother is homozygous recessive

b
This combination of parents cannot produce children with the AB blood type

c
This combination of parents cannot produce children with the O blood type

d
Approximately 50% of their children will have type A blood

Question 2

A couple has just found out that they are going to have a male child. The mother has hemophilia; the father does not have hemophilia. If they know that the child will be male, what is the chance that their male child will develop hemophilia (the hemophilia allele is recessive and found on the X chromosome)?

a
0%

b
25%

c
50%

d
75%

e
100%

Answer 2

e
100%

Question 3

Though it is a common example of a recessive genetic disorder, phenylketonuria (PKU) is also an example of another genetics concept that we discussed in this course. Individuals with PKU that do not control their intake of phenylalanine show a wide variety of symptoms due to the buildup of phenylalanine and its byproducts in their systems. These symptoms include hyperactivity, light pigmentation, and delayed development. Based on this information, PKU is an example of:

a
epistasis

b
plieotropy

c
mitochondrial inheritance

d
polygenic inheritance

e
linked genes

Answer 3

b
plieotropy

Question 4

Your neighbor has planted a bed of pink snapdragons in his yard. As the growing season progresses, he notices that some white and red snapdragons are popping up in what was supposed to be a bed of pink flowers. Explain to him the reason that this is happening, knowing that pink is the phenotype coded for by a heterozygous genotype in the flower color of snapdragons.

Answer 4

This color gene is inherited through incomplete dominance. The heterozygous pink flowers have one copy of the red color allele and one copy of the white color allele, either of which they can pass to their offspring, resulting in red or white offspring when homozygous

Question 5

Usually, evolution by natural selection eliminates alleles that kill individuals of a species. Nonetheless, some lethal genetic diseases exist in humans - cystic fibrosis, sickle cell anemia, Huntington, to name a few. Why do these genetic disorders persist in human population, despite being lethal to individuals with the disorder? In your answer, consider recessively inherited diseases separately from dominantly inherited diseases.

Answer 5

Dominant diseases can persist if they have their effects after most individuals would have already reproduced. Recessive disorders can persist in carriers/heterozygotes with little to no harm to individuals that carry them. Sometimes, heterozygotes are even at an advantage over those who do not carry the recessive disease allele, as seen in individuals who are heterozygous for sickle cell being resistant to malaria

Question 6

Given the DNA sequence:

TAC-GTA-CCA-AAA-TTT-ATA-ATT

a) What is the corresponding RNA sequence?

b) What is the sequence of amino acids in the protein?

Answer 6

a) AUG-CAU-GGU-UUU-AAA-UAU-UAA b) Met-His-Gly-Phe-Lys-Tyr

Question 7

PCR is a common laboratory technique that is used to create many copies of a DNA sequence. Imagine that you are trying to perform PCR in your lab, but your thermocycler is not working. The thermocycler raises and lowers the temperature for each cycle of a PCR reaction. Given that the function of raising and lowering the temperature is to separate the DNA strands, which of the following enzymes might you add as a substitute for the temperature change?

a
Helicase

b
Telomerase

c
Primase

d
Topoisomerase

e
Ligase

Answer 7

a
Helicase

Question 8

A single fat cell can produce two different proteins (one longer and one slightly shorter amino acid sequence) from the same gene at different times during development. The best explanation for this out of the following is the process of:

a
heterozygosity

b
semiconservative replication

c
epigenetics

d
alternative mRNA splicing

e
wobble pairing

Answer 8

d
alternative mRNA splicing

Question 9

You injected some mRNAs into the cytoplasm of a yeast cell in order to force the yeast cell to make the protein coded for by the mRNA. Nonetheless, you mistakenly assumed that yeast are prokaryotes (when they are actually eukaryotic), so you did not think to add 5’ caps and poly(A) tails to the mRNAs. Assuming you did everything else correctly, which of the following is a likely consequence of your mistake?

a
tRNA would not have the right anti-codons to bind to this mRNA

b
The introns would not be removed from this mRNA

c
RNA polymerase would not easily bind to this mRNA

d
The rate of translation of this mRNA would be slower than if you had not made this mistake

e
Transcription of the gene would occur at a slower rate than normal

Answer 9

d
The rate of translation of this mRNA would be slower than if you had not made this mistake

Question 10

A specific archaeon species is discovered that has a different gene expression pattern than most organisms. Instead of the codon UUU coding for the amino acid phenylalanine, UUU codes for valine in this species. That is, every time there is a UUU in the mRNA of this species, a valine is added to the protein instead of the more normal phenylalanine being added. Which of the following genes is likely mutated in this archaeon species?

a
a gene coding for a sgRNA

b
a gene coding for part of the large ribosomal subunit

c
a gene coding for an aminoacyl-tRNA synthetase

d
a gene coding for a transcription factor

e
a gene coding for RNA polymerase

Answer 10

c
a gene coding for an aminoacyl-tRNA synthetase

Question 11

Given the DNA sequence: TAC-AGC-GCA-CCC-AAA-GAA-ACC-ATT
which of the following mutations would no effect on the amino acid sequence of the protein produced from this gene?

a
A mutation that changed the first A in the DNA to a T

b
A mutation that deleted the second A in the DNA sequence

c
A mutation that changed the last A in the DNA sequence to a G

d
A mutation that changed the last C into a T in the DNA sequence

e
A mutation that changed the second C in the DNA sequence to a G

Answer 11

e
A mutation that changed the second C in the DNA sequence to a G

Question 12

which of the following are true of mutations

a
Only mutations that affect the sperm and egg can be passed on to the next generation

b
Additions or subtractions of nucleotides in a gene sequence are more likely to cause a loss-of-function of the protein produced by that gene than are mutations that substitute one nucleotide for another

c
Though mutations can be good, bad, or neutral for the individual that they occur in, they are important in the context of evolution because they create new variation

d
Though an incorrect nucleotide is sometimes added during DNA synthesis, DNA polymerase often corrects its own mistakes before continuing to add more nucleotides

Answer 12

a
Only mutations that affect the sperm and egg can be passed on to the next generation

b
Additions or subtractions of nucleotides in a gene sequence are more likely to cause a loss-of-function of the protein produced by that gene than are mutations that substitute one nucleotide for another

c
Though mutations can be good, bad, or neutral for the individual that they occur in, they are important in the context of evolution because they create new variation

d
Though an incorrect nucleotide is sometimes added during DNA synthesis, DNA polymerase often corrects its own mistakes before continuing to add more nucleotides

Question 13

Imagine you are trying to insert a prokaryotic gene into a eukaryotic organism. You know that you need the nucleotide sequence encoding the gene itself. Based on what you know of transcription and translation, which out of the following would you also need to add to the sequence in order for the gene to be expressed correctly in a eukaryote?

a
a eukaryotic promotor sequence

b
introns

c
-35 and -10 boxes

d
sequences to code for prokaryotic tRNAs

e
sequences to code for the sigma protein

Answer 13

a
a eukaryotic promotor sequence

Question 14

Imagine that you’ve discovered a mutant eukaryotic line of cells whose histone proteins have more negatively charged amino acids in them than are present in normal histone proteins. In these mutants, you would expect:

a
This would increase gene expression because histone proteins would associate more closely with DNA

b
This would decrease gene expression because histone proteins would associate more closely with DNA

c
This would increase gene expression because histone proteins would associate less closely with DNA

d
This would decrease gene expression because histone proteins would associate less closely with DNA

Answer 14

c
This would increase gene expression because histone proteins would associate less closely with DNA

Question 15

You isolate a mutant eukaryotic cell that can’t produce the RISC protein, so they are unable to use RNA interference to control gene expression. Which of the following would be an effect of this mutation, in comparison with a normal eukaryotic cell?

a
Fewer proteins would be made in the cell

b
Fewer transcription factors would be needed to activate transcription of genes

c
There would be more mRNA molecules in the cell

d
The chromatin would be significantly less condensed

e
Less alternative RNA splicing would occur in the cell

Answer 15

c
There would be more mRNA molecules in the cell

Question 16

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the operator past the genes encoding proteins for lactose metabolism (instead of in front of the genes), which of the following would likely occur in this cell?

a
The repressor protein will no longer be produced

b
Lactose will no longer bind to the repressor protein

c
The repressor protein will no longer bind to the operator

d
The lactose metabolism genes will be able to be transcribed continuously

e
The lactose metabolism genes will never be transcribed

Answer 16

d
The lactose metabolism genes will be able to be transcribed continuously

Question 17

A researcher injects a master regulator for muscle into an area of a mouse embryo that normally would have developed into fat. Instead of becoming fat, the cells affected by the master regulator become muscle cells. These cells:

a
underwent apoptosis

b
are now considered iPS cells

c
likely contain fewer epigenetic tags than they did before the master regulator was added

d
were not yet irreversibly determined when the master regulator was added

e
contain too many imprinted genes to become fat cells

Answer 17

d
were not yet irreversibly determined when the master regulator was added

Question 18

Your friend Aynsley is unconvinced that evolution is real. Her line of argument is that “evolution is just a theory” so it must not hold weight in the scientific community. What is the most scientifically accurate way of responding to this?

a
Theories are educated guesses, so her argument is valid.

b
Evolution is actually a law, so her argument is irrelevant

c
Theories result from the unification of the results of many experiments, so they are highly supported by evidence

d
Theories are not testable, so it is not actually important whether evolution is a theory or not

e
None of the above are true

Answer 18

c
Theories result from the unification of the results of many experiments, so they are highly supported by evidence

Question 19

You have a solution that contains carbohydrates and you want to know which carbohydrates are in the solution. Unfortunately, the machine that you have to analyze carbohydrates can only identify different types of monosaccharides. You decide to add an enzyme to your solution to break down all carbohydrates into monosaccharides. Once the solution has been broken down completely into monosaccharides, you find that the only monosaccharide present is glucose. Which of the following could you eliminate as a possible component of your carbohydrate solution, based on this information?

a
starch

b
cellulose

c
glycogen

d
You cannot eliminate any of the above. It could be any of them.

e
You can eliminate all of the above. This cannot be starch or glycogen or cellulose.

Answer 19

d
You cannot eliminate any of the above. It could be any of them.

Question 20

You notice in the ameoba cells that you are studying that the concentration of Na+ is consistently higher inside of the cell than it is in the solution outside the cell. Based on this you know that:

a
the cells must be using facilitated diffusion to concentrate the Na+ on the inside of the cell

b
the cell membrane, like most cell membranes, must be highly permeable to Na+

c
the cells must be actively transporting Na+ into the cell

d
the nonpolar molecules in the cell must be attracting the Na+

e
the Na+ must be a steroid hormone

Answer 20

c
the cells must be actively transporting Na+ into the cell

Question 21

You are looking at slides in lab and see a single-celled organism. The cell contains, among other things, mitochondria. What can you tell about the organism, based on this observation?

a
This organism is a bacterium

b
This organism is an archaeon

c
This organism is a eukaryote

d
Two of the above are possible

e
Any of the above are possible

Answer 21

c
This organism is a eukaryote

Question 22

Which of the following is true concerning chromosomes and cell division?

a
Each chromosome contains multiple genomes

b
Smaller chromosomes tend to have more genes, therefore it tends to be a larger problem if there is an extra copy of a smaller chromosome than if there is an extra copy of a larger one

c
Meiosis results in two identical cells whereas mitosis creates diverse new cells

d
Nondisjunction is when chromosomes don’t separate properly during cell division. It can cause cells to have too many or two few copies of a chromosome

e
All of the above are false

Answer 22

d
Nondisjunction is when chromosomes don’t separate properly during cell division. It can cause cells to have too many or two few copies of a chromosome

Question 23

Which of the following is a correct comparison of the light-capturing reactions and the Calvin cycle of photosynthesis?

a
Some of the products of the light-capturing reactions are reactants in the Calvin cycle and vice versa

b
The light-capturing reactions only occur during the day and the Calvin cycle only occurs at night

c
The light-capturing reactions require green light, whereas the Calvin cycle requires other wavelengths of light

d
The light capturing reactions build G3P whereas the Calvin cycle builds glucose

Answer 23

a
Some of the products of the light-capturing reactions are reactants in the Calvin cycle and vice versa