Exam II Review Questions

Question 1

Where does the mass of a tree come from?

A. Water
B. Minerals from the soil
C. Air
D. Sunlight
E. Other

Answer 1

C

Question 2

You have a friend who lost 15 pounds through exercise and a change in diet.
Where did the weight go?

A. It was released as CO2 and H2O.
B. It was converted to heat and then released.
C. It was converted to ATP, which weighs less than fat.
D. It was broken down into amino acids and eliminated from the body.
E. It was converted to urine and eliminated from the body.

Answer 2

A

Question 3

Respiration ______, and cellular respiration ______.

A. produces glucose . . . produces oxygen
B. is gas exchange . . . produces ATP
C. uses glucose . . . produces glucose
D. produces glucose . . . is gas exchange
E. produces ATP . . . is gas exchange

Answer 3

B

Question 4

If oxygen is unavailable, predict what will happen to the citric acid cycle.

A. It will continue because none of the reactions in the citric acid cycle require oxygen.
B. It will stop because ADP levels will increase in the absence of oxygen.
C. It will stop because the supplies of NAD+ and FAD will become depleted.
D. It will continue because ATP levels will be low, and low ATP activates enzymes of the
cycle.

Answer 4

A

Question 5

A major difference between anaerobic respiration and anaerobic fermentation is ____________.

a. in the use of oxygen
b. that the former requires breathing
c. that the latter uses organic molecules within the cell as final electron acceptors
d. that fermentation only produces alcohol

Answer 5

C

Question 6

If you were able to stop the process of cellular respiration after completion of electron transport but prior to chemiosmosis, where would the pH of a mitochondrion to be at its lowest?

[Hint: remember pH is determined by the concentration of H+ ions]

A. in the cytoplasm
B. on the inner membrane
C. in the mitochondrial matrix
D. in the intermembrane space
E. on the outer membrane

Answer 6

D

Question 7

Phosphorylating glucose helps “trap” it in a cell so it can be broken down.

A. Is the forward reaction endergonic or exergonic?
B. Is it anabolic or catabolic?
C. Is it dehydration synthesis or hydrolysis?

Answer 7

endergonic; catabolic; dehydration synthesis

Question 8

What is the DG0 of Glucose and ATP turning into Gluce-6-phosphate and ADP?

a) 10 kcal/mol
b) -10 kcal/mol
c) 4 kcal/mol
d) -4 kcal/mol

Answer 8

D

Question 9

DCMU harms plants because…

a) It stops them from synthesizing ATP via chemiosmosis, so there is no energy to assemble CO2 into sugar.
b) It stops them from reducing CO2 to glucose, since there’s no source of high-energy electrons for the Calvin cycle.
c) It stops them from pumping protons, so there is no energy to assemble CO2 into sugar.
d) It causes an accumulation of oxygen, which blocks the Calvin cycle.

Answer 9

B

Question 10

Which of the Following Statements Are True?

A. Photosynthesis converts sunlight (energy) into glucose (matter).
B. In the light-dependent reactions, sunlight is used to assemble CO2 molecules into sugar.
C. In the light-independent reactions, sugar is produced.
D. The Calvin cycle is another term for the light-independent reactions.

Answer 10

B, C, D

Question 11

The porphyrin ring (top) is excited by light. Lots of conjugated double bonds!
What does the circled part do?

a) Donates protons to solution when exposed to light.
b) Accepts protons when exposed to light
c) Embeds the chlorophyll in hydrophilic parts of the thylakoid membrane.
d) Embeds the chlorophyll in hydrophobic parts of the thylakoid membrane.

Answer 11

D

Question 12

During the light reactions of photosynthesis, the transport chain pumps H+ into the thylakoid.
This gradient will be directly used to power:

a) ATP synthase
b) The citric acid cycle
c) Starch synthase
d) NADH synthase

Answer 12

A

Question 13

During the light reactions of photosynthesis, which area has the highest pH?
The lowest pH?

Answer 13

The stroma; thylakoid lumen

Question 14

Each sperm cell of a horse contains 32 chromosomes. How many chromosomes are there in each of the horse’s body cells?

A. 32
B. 16
C. 16 pairs
D. 64
E. either 16 or 64, depending on the cell type

Answer 14

D

Question 15

Which of the following is a consequence of sexual reproduction, as compared to asexual reproduction?

A. There will be fewer mutations.
B. The offspring will be very similar to each other.
C. There will be more genetic diversity among the offspring.
D. The offspring will have a diploid chromosome number twice that of their parents.
E. There will be few offspring with undesirable traits.

Answer 15

C

Question 16

Which of the following are true? Choose all that apply.

A. Unlike mitosis, meiosis I condenses chromosomes in prophase.
B. Unlike mitosis, meiosis I requires homologous chromosomes to pair up in prophase.
C. Unlike mitosis, meiosis I separates homologous chromosomes in anaphase.
D. Meiosis II converts diploid cells into haploid cells.
E. Unlike mitosis, meiosis I includes recombination between homologous chromosomes under normal conditions.
F. Meiosis II separates sister chromatids, just as mitosis does.

Answer 16

B, C, E, F

Question 17

Which of these is a genotype and which is a phenotype?

a) Whether I carry DNA encoding a type A red blood cell surface marker.
b) My blood type

Answer 17

Genotype; Phenotype

Question 18

1. In a Punnett square, the column and row headers correspond to the products of…

Meiosis or Fertilization

2. In a Punnett square, the cells in the grid correspond to the products of…

Meiosis or Fertilization

Answer 18

Meiosis; Fertilization

Question 19

In humans, free earlobes (E) are dominant to attached earlobes (e) and the presence of freckles
(F) is dominant to the absence of freckles (f). A man heterozygous for both of these traits has a
girlfriend with attached earlobes and no freckles.
What is the probability of their having a child with attached earlobes and freckles?

A. 100%
B. 50%
C. 75%
D. 0%
E. 25%

Answer 19

E

Question 20

Which are true? Choose all that apply.

A. Low genetic diversity increases overall disease risk to a population.
B. Asexual reproduction greatly increases genetic diversity.
C. In sexual reproduction, sperm and egg each contribute roughly 50% of the alleles to the offspring.
D. Organisms can do sexual reproduction OR asexual reproduction, but never both.

Answer 20

A, C

Question 21

Red-green color blindness is inherited as an X-linked recessive.
How can a man with normal color vision father an XX daughter who is red-green color-blind?

A. He can’t (unless there is a mutation).
B. Though he has normal color vision, the man is actually homozygous for the red-green color
blindness allele.
C. Though he has normal color vision, the man is actually heterozygous for the red-green color
blindness allele.
D. The man’s mother carries an allele for red-green color blindness, and the expression of the
trait skipped a generation.
E. The child’s mother is red-green color-blind.

Answer 21

A

Question 22

Which enzyme unwinds the DNA initially?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 22

Helicase

Question 23

Which enzyme makes a small piece of RNA on the DNA template to start copying?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 23

Primase

Question 24

Which enzyme fills in the unreplicated ends of eukaryotic chromosomes?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 24

Telomerase

Question 25

Which enzyme adds new DNA nucleotides to the 3’ end of a growing chain?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 25

DNA Polymerase

Question 26

Which enzyme relieves tension in unwound DNA?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 26

Topoisomerase

Question 27

Which enzyme connects fragments of DNA together?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 27

Ligase

Question 28

Which enzyme keeps separated strands from sticking together?

Ligase, Helicase, DNA Polymerase, Primase, Telomerase, Topoisomerase, or SSBs

Answer 28

SSBs or
Single-stranded binding proteins

Question 29

The DNA of a certain organism has guanine (G) as 30% of its bases.
What percentage of its bases would be adenine (A)?

A. 60%
B. 30%
C. 20%
D. 40%
E. 50%

Answer 29

C

Question 30

Which of the following are true? Choose all that apply!

A. The coding strand is the one that RNA Polymerase II directly uses to pair up RNA.
B. In both eukaryotes and prokaryotes, an A base in DNA pairs with a U base in RNA.
C. In prokaryotes, the translation of RNA can begin before its transcription is finished.
D. Every strand of prokaryotic mRNA codes for one protein.

Answer 30

B, C, D

Question 31

Protein that controls whether RNA polymerase binds to DNA, especially in eukaryotes.

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 31

Transcription factor

Question 32

Protein that binds to DNA and transcribes RNA.

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 32

RNA polymerase

Question 33

DNA that is complementary to the template strand.

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 33

Coding (non-template) strand

Question 34

DNA region that recruits transcription proteins, such as RNA Polymerase.

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 34

Promoter

Question 35

Non-DNA copy of the DNA with regions that will be translated to protein.

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 35

RNA

Question 36

DNA strand that is directly copied by RNA polymerase (polymerase moves along this.)

Coding (non-template) strand, RNA, RNA polymerase, Template strand, Promoter, Transcription factor

Answer 36

Template strand

Question 37

Which of the Following Are True? Choose All that Apply

A. In eukaryotes, RNA polymerase II can bind stably to promoter regions on its own.
B. Both prokaryotes and eukaryotes have an AT-rich region upstream of the start of transcription.
C. RNA transcribed by eukaryotes can be directly translated to protein.
D. Both prokaryotes and eukaryotes can use additional transcription factors to modify gene expression.

Answer 37

B, D

Question 38

Which of the following are true? Choose all that apply!

a) The coding strand is the one that RNA Polymerase II directly uses to pair up RNA.
b) In both eukaryotes and prokaryotes, an A base in DNA pairs with a U base in RNA.
c) In prokaryotes, the translation of RNA can begin before its transcription is finished.
d) Every strand of prokaryotic mRNA codes for one protein.

Answer 38

B, C, D

Question 39

Which Are True? Choose All that Apply.

a) Both the 5’ cap and the 3’ poly-A tail help protect the RNA from being broken down.
b) Both the 5’ cap and the 3’ poly-A tail help the RNA leave the nucleus.
c) Both the 5’ cap and the 3’ poly-A tail can help target the RNA to the ribosome for translation.
d) Both the 5’ cap and the 3’ poly-A tail are hundreds of bases long.

Answer 39

A, B, C

Question 40

Which of the Following Are True? Choose All that Apply

A. Splicing of protein-coding genes is common in eukaryotes, but does not happen in prokaryotes.
B. Some RNAs can act as enzymes, and even catalyze their own splicing.
C. snRNPs are ribonucleoproteins, and thus made entirely of protein.
D. Alternative splicing allows many different protein sequences to be coded by one gene.
E. Eukaryotic introns are usually translated to protein.

Answer 40

A, B, D

Question 41

Which one of these best explains the need for nuclear pores?

A) DNA needs to get in.
B) DNA needs to get out.
C) RNA needs to get in.
D) RNA needs to get out.

Answer 41

D

Question 42

Which amino acid is encoded by AGA?

a) Lys
b) Ala
c) Arg
d) Gly

Answer 42

C

Question 43

A person copies a gene from the human genome puts it in a bacterial cell.
The bacterium transcribes RNA from the DNA sequence…
…but translation of this RNA does NOT result in a functional protein.
Why wasn’t the human gene successfully translated to bacterial protein?

a) Bacteria have different DNA bases from humans (do not use ATCG).
b) Bacteria have different RNA bases from humans (do not use AUCG).
c) The bacterium cannot remove exons from the RNA.
d) The bacterium cannot remove introns from the RNA.

Answer 43

C

Question 44

Which of the following are true? Choose all that apply.

a) Each type of aminoacyl-tRNA synthetase enzyme charges tRNA molecules with one specific amino acid.
b) Each codon specifies one amino acid and is not usually read to mean another amino acid. (Code is not ambiguous)
c) More than one codon can give the same amino acid. (Code is redundant)
d) Every tRNA molecule carries one specific amino acid, and no other.

Answer 44

A, B, C, D

Question 45

Which of the codons is capable of terminating translation?

a) UAG
b) UGA
c) UAA
d) All of these choices are correct.

Answer 45

D

Question 46

A bacterial protein is made up of 30 amino acids.

How many nucleotides will code for this protein?
Would this answer apply to a similarly-sized plant protein?
Why or why not?

Answer 46

90; No, because plants carry out splicing.

Question 47

Match each example mutation to its name.

A) ACGT -> ACTT
B) ACGT -> ACT
C) ACGT -> ACGGT

Answer 47

A) Substitution
B) Deletion
C) Insertion

Question 48

Match each example mutation to its name.

ABCDE -> ABDEC

Answer 48

Insertion

Question 49

Match each example mutation to its name.

ABCDE -> ABEDC

Answer 49

Translocation

Question 50

Match each example mutation to its name.

ABCDE -> ABCBCDE

Answer 50

Duplication

Question 51

Match each example mutation to its name.

ABCDE -> ACBDE

Answer 51

Inversion

Question 52

Match each example mutation to its name.

ABCDE -> ACDE

Answer 52

Deletion

Question 53

Which one of the following would NOT cause a frame-shift error?

a) Deleting a T from the DNA shortly after ATG.
b) Inserting CG into the DNA shortly after ATG
c) Inserting CGG into the DNA shortly after ATG
d) Deleting CC from the DNA shortly after ATG

Answer 53

C

Question 54

Which of the following are true? Choose all that apply

A. Euchromatin is generally easier to sequence than heterochromatin.
B. Plants are simpler than animals, and thus tend to have smaller genomes.
C. Almost all the human genome codes directly for proteins.
D. The Human Genome Project was international in scope.

Answer 54

A, D

Question 55

Why is DNP a poison? What happens to the mitochondria and ATP production when it is ingested?

Answer 55

DNP is a poison because it allows protons to leak through the matrix, meaning that its energy isn’t being harnessed via ATP synthase, which drastically decreases the amount of ATP produced for each molecule of glucose, heavily hindering energy levels.

Question 56

Why is cyanide a poison? What happens to the mitochondria and ATP production when it is ingested?

Answer 56

When cyanide is ingested, it binds to Complex IV, which prevents oxygen from being utilized by the cell, meaning that NADH rapidly builds up, shutting down the cell’s ability to produce ATP, and causing it to suffocate. Ingestion of cyanide leads to hypoxia, despite the presence of oxygen.

Question 57

In which direction does replication occur?

Answer 57

5’ to 3’

Question 58

What happens in a human muscle cell when the person is working out so hard that the cells are not getting enough oxygen?

Answer 58

When a person is working out so hard that their cells are not getting enough oxygen, their muscle cells go into anaerobic metabolism, where it breaks down glucose without oxygen, which leads to a build up of lactic acid.

Question 59

How is fermentation used to make alcoholic beverages like beer, wine, bread, etc.?

Answer 59

Alcoholic beverages such as beer and wine, as well as foods such as bread, rely on fermentation, where yeast and sugar are mixed together and deprived of oxygen, which results in the production of carbon dioxide and alcohol.

Question 60

How do our bodies make energy from food? Explain how our bodies make energy during cell respiration, how much energy is made, and the roles of glucose, oxygen, carbon dioxide, and hydrogen in this process. Your answer should discuss glycolysis, citric acid cycle and the electron transport chain.

Answer 60

The cells in our body break down food during cellular respiration in order to produce energy. This process starts in glycolysis when a molecule of glucose is broken down into two molecules of pyruvate. Next, during the pyruvate oxidation step, pyruvate is converted into acetyl-CoA, which produces carbon dioxide as a byproduct, and gives an electron to NAD+, turning it into NADH. From here, acetyl-CoA turns into citrate, which is broken down into carbon dioxide and donates electrons to NAD+ and FADH to produce NADH and FADH2. In the electron transport chain, protons are pumped across the membrane, creating a concentration gradient that allows ATP synthase to then harvest the energy from those protons to produce large amounts of ATP.