BIO 183 Final Exam

Calcium is an important intracellular messenger a. True b. False

a. True

The cloverleaf-shaped molecule that carries an anticodon at one end and an amino acid at the other is called mRNA tRNA ShRNA SiRNA

tRNA

Intracellular receptors that affect gene expression (as is the case for steroid receptors, for instance) typically have faster effects that transmembrane receptors such as GPCRs or RTKs True False

False

A nucleotide mutation that converts a regular codon (coding for an amino acid) into a STOP codon is called

A nonsense mutation

Which of the following best describes proteasomes? a. A proteasome is protein complex whose purpose is to hydrolyse ubiquinated proteins. b. A proteasome a generic term that describes a specific sequence of amino acids that performs similar functions in all proteins in which it is found. c. A proteasome is a vesicle that carries proteins in the cytoplasm d. A proteasome is an enzyme that converts mRNA into proteins

A proteasome is protein complex whose purpose is to hydrolyse ubiquinated proteins.

In what phase of meiosis do homologous chromosomes line up in the middle of the cell? a. Metaphase I b. Metaphase II c. Anaphase I d. Anaphase II

During a typical cell cycle, the interphase is composed of which of the following phases a. G1, S, G2, Mitosis b. G1, S, G2 only c. G1, S, G2, Meiosis d. Interphase is the gap between G1 and G2

In eukaryotes, the process described in the previous question takes place mainly... In the nucleus Both B and C are correct In the cytoplasm In/on the rough endoplasmic reticulum

In/on the rough endoplasmic reticulum

During the initiation of translation in eukaryotes, the first tRNA is brought into which site of which ribosomal subunit? The A site of 40S subunit The P site of 60S subunit The A site of the 30S subunit The E site of 60S subunit

The P site of 60S subunit

Aminoacyl-tRNA synthetases are extremely specific enzymes. Without this high level of specificity,

The amino acid sequence of polypeptide would often be wrong

Upon binding of a ligand, receptor tyrosine kinases do which of the following? a. They activate nearby G-proteins b. They migrate to the nucleus to activate/repress specific genes c. They dimerize, autophosphorylate, and trigger a cascade in intracellular signal transduction/phosphorylation d. They induce apoptosis

They dimerize, autophosphorylate, and trigger a cascade in intracellular signal transduction/phosphorylation

The purpose of the 5' cap on eukaryotic mRNA is

To allow the attachment of ribosomes

The process of converting an mRNA sequence into a polypeptide is called Transcription Conversion Translation Gene expression

Translation

Which of the following are produced during aerobic cellular respiration? a. 36-38 ATPs b. 2 ATPs and lactic acid c. 36 -38 ATPs and ethanol d. 2 ATPs and ethanol

a. 36-38 ATPs

Which of the following structures would least likely be found as part of a bacterium? a. A lysosome b. A plasma membrane c. An enzyme d. A ribosome

a. A lysosome

Okazaki fragment exist because a. DNA polymerase III can only read DNA in the 3' to 5' direction b. RNA polymerase II can only read DNA in the 5' to 3' direction c. DNA polymerase I can only read DNA in the 5' to 3' direction d. The lagging strand has a 3' overhang

a. DNA polymerase III can only read DNA in the 3' to 5' direction

Cortisol is a signaling molecule released in the blood stream by adrenal glands (Located in your lower back). Its effects on the brain are an example of which of the following? a. Endocrine signaling b. Autocrine signaling c. Paracrine signaling d. Direct contact e. None of the above

a. Endocrine signaling

The signaling molecules that bind to receptors to activate them are also known as a. Ligands b. Substrates c. Enzymes d. Dimers

a. Ligands

Which of the following best describes G-protein-coupled receptors a. Receptor-associated, intracellular protein complexes composed of 3 subunits b. Transcription factors found in the cell nucleus c. Ligand-gated channels d. Autophosphorylating kinases

a. Receptor-associated, intracellular protein complexes composed of 3 subunits

DNA replication is known to follow which of the following patterns a. Semi-conservative mechanism b. Conservative mechanism c. Dispersive mechanism d. Untraditional mechanism

a. Semi-conservative mechanism

The LacI gene is constitutively active, which suggests which of the following a. The CAP protein is made continuously b. Allolactose is always present c. The Lac operon is always expressed d. The Lac repressor is made constantly

a. The CAP protein is made continuously

The main function of glycoproteins in the cell membrane is a. To give cells an identity that allows them to be recognized by other cells (ex immune system cells) b. Anchoring of cells to the extracellular matrix c. To act as an energy storage d. To form a cytoskeleton

a. To give cells an identity that allows them to be recognized by other cells (ex immune system cells)

A hypothetical cell whose plasma membrane is made of a phospholipid bilayer only (no channels or anything of that sort) is placed in a solution of 100mM NaCl. The intracellular NaCl concentration is 200mM. What would you expect to observe? a. Water would move in the cell by osmosis b. Nothing would happen. The membrane is impermeable to NaCl and water c. NaCl would move out of the cell, down its concentration gradient d. Water would move out of the cell by osmosis e. NaCl would be pumped out of the cell

a. Water would move in the cell by osmosis

Match the level of protein structure on the left with the appropriate description on the right. i. Primary w. 3-dimensional shape of polypeptide chain ii. Secondary x. linear sequence of amino acids iii. Tertiary y. assembly of subunits into functional protein iv. Quaternary z. hydrogen bonding within peptide backbone (ex: α-helix, β-pleated sheet)) a. i=x, ii=z, iii=w, iv=y b. i=y, ii=w, iii=x, iv=z c. i=x, ii=w, iii=z, iv=y d. i=z, ii=x, iii=y, iv=w

a. i=x, ii=z, iii=w, iv=y

The plasma membrane is best described as: a. A double layer of proteins that is impermeable to water, but allows free movement of ions b. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carbohydrate molecules c. A stiff double membrane composed of phospholipids, proteins, and nucleic acids d. A double layer made entirely of glycoproteins, glycolipids, and cholesterol

b. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carbohydrate molecules

Which of the following is a monosaccharide? a. Sucrose b. Fructose c. Lactose d. Starch

b. Fructose

Enzymes catalyze chemical reactions by a. Converting substrates and products in their allosteric site b. Lowering the activation energy necessary to start the reaction c. Increasing gene activity d. Phosphorylating all substrates in the reaction

b. Lowering the activation energy necessary to start the reaction

The final electron acceptor in the electron transport chain of thylakoids is a. ATP b. NADP+ c. Oxygen d. FADH2

b. NADP+

Which of the following best explains the process of photosynthesis a. Photosynthesis works best with green light b. Photosynthesis decreases when chloroplasts are exposed to green light only c. The rate of photosynthesis is at its highest outside of the visible light spectrum d. The rate of photosynthesis is at its highest in the X-ray range of the electromagnetic spectrum

b. Photosynthesis decreases when chloroplasts are exposed to green light only

Which of the following are you least likely to find inside a virus? a. Single-stranded DNA b. RNA polymerase c. Reverse transcriptase d. Single stranded RNA e. Integrase

b. RNA polymerase

Which of the following is false about the repressor encoded by the lac regulatory gene? a. The repressor binds to the operator b. The repressor is inhibited by beta-galactosidase c. The repressor is the product of the LacI gene d. The repressor is active when lactose is not present

b. The repressor is inhibited by beta-galactosidase

The main difference between active and passive transport across a cell membrane is a. Active transport requires channels while passive transport does not b. Active transport requires carrier proteins while passive transport does not c. Active transport requires energy while passive transport does not d. Active transport is always much faster than passive transport

c. Active transport requires energy while passive transport does not

The sum of all intracellular reactions involved in the building up of macromolecules is called a. Catabolism b. Catalysis c. Anabolism d. Hydrolysis e. Metabolism

c. Anabolism

The pattern of inheritance illustrated by the various blood types is an example of a. Incomplete dominance b. Epistasis c. Codominance d. Sex-linked inheritance

c. Codominance

Polymers of macromolecules (carbohydrates, fats, and proteins) can be assembled from individual monomers by which process? a. Hydrolysis (addition of water molecules) b. Catalysis c. Dehydration (or condensation) reaction d. The formation of peptide bonds between monomers

c. Dehydration (or condensation) reaction

Two F1 generation offsprings of a monohybrid cross have similar phenotypes. In order to determine whether those 2 organisms are homozygous dominant or heterozygous, one may attempt to a. To cross those organisms with the P generation b. Cross those organisms with each other c. Do a testcross d. The only way to address this question is by sequencing their whole genome

c. Do a testcross

The advantages of using Ca2+ and cAMP downstream of G-protein-coupled receptors are a. Preservation of ATP b. Conservation of energy c. Enhancement of signal amplification and speed d. Ca2+ and cAMP are always readily available in the endoplasmic reticulum e. None of the above

c. Enhancement of signal amplification and speed

Which of the following is true regarding extranuclear inheritance? a. Extranuclear inheritance happens only in prokaryotes b. Extranuclear inheritance follows a pattern of independent allele segregation c. Extranuclear inheritance refers mainly to mitochondrial and chloroplast DNA d. Extranuclear inheritance follows the patterns of inheritance hypothesized by Mendel

c. Extranuclear inheritance refers mainly to mitochondrial and chloroplast DNA

The protein complexes that pull sister chromatids apart from each other along the spindle apparatus during mitosis are known as a. Centrioles b. Karyotypes c. Kinetochores d. Spliceosomes

c. Kinetochores

The 2 main stages of photosynthesis in chloroplasts are a. Photosynthesis and glocuneogenesis b. Oxydative phophorylation and Citric acid cycle c. Light reactions and Calvin cycle d. Light and heavy reactions

c. Light reactions and Calvin cycle

Which of the following is true about gene regulation during transcription? a. Active DNA regions tend to have methylated histones b. Inactive DNA regions tend to have acetylated histones c. Nucleosomes may be displaced or remodeled d. Only answers a and b are true

c. Nucleosomes may be displaced or remodeled

During oxydative phosphorylation, the final electron acceptor at the end of the electron transport chain is a. ATP synthase b. H20 c. O2 d. CO2

c. O2

In lungs, O2 moves freely across the cell membrane of alveoli, down its concentration gradient, and without the requirement of any carrier protein or any input of external energy. This is an example of a. Active transport b. Osmosis c. Passive diffusion d. Facilitated diffusion e. Cotransport

c. Passive diffusion

In cellular respiration, which of the following are products of glycolysis? a. Acetyl CoA and ATP b. Acetyl CoA and citric acid c. Pyruvate, ATP, and NADH d. Pyruvate, ATP, and Acetyl CoA

c. Pyruvate, ATP, and NADH

During cellular respiration, glycolysis takes place in which of the following? a. Mitochondria b. Chloroplasts c. The cytoplasm d. Glycosomes

c. The cytoplasm

Genes can be found on both strands of DNA. The strand that is being read in order to make mRNA is a. The leading strand b. The lagging strand c. The template strand d. The coding strand

c. The template strand

The method you used in lab to insert a GFP-encoding plasmid in bacteria is called a. Transduction b. Mad skills (don't pick this answer!) c. Transformation d. Conjugation

c. Transformation

The main electron donor to photosystem 2, in the electron transport chain of the thylakoid membrane is a. Oxygen b. NADPH c. Water d. ATP

c. Water

According to the theory of alternative splicing... a. One gene may encode for more than one protein b. One sequence of mRNA may be split into several subunits c. Various tissues may express the same genes differently d. All of the above statements are correct

d. All of the above statements are correct

Which of the following is true about transcription factors in eukaryotes? a. They tend to bind DNA in the area of the TATA box (when present) b. They tend to bind DNA in the major grooves c. They often form complexes made of several subunits d. All of the above statements are true

d. All of the above statements are true

Which of the following factors affects plasma membrane fluidity? a. Length of fatty acyl chains b. Presence of double bonds in the fatty acyl chains c. Presence of cholesterol d. All of these factors (a, b, and c) influence membrane fluidity

d. All of these factors (a, b, and c) influence membrane fluidity

Which of the following is true about nucleosomes? a. Nucleosomes are composed of histones arranged in a zig-zag pattern to make a 30nm DNA fiber b. Nucleosomes are made of 9 histones c. Nucleosomes contribute greatly to DNA compaction d. All of these statements (a, b, and c) are true

d. All of these statements (a, b, and c) are true

Which of the following is true about telomerase a. Telomerase extends the 3' end of DNA strands by a few nucleotides b. Telomerase activity decreases over time c. Telomerase contains its own template of repetitive nucleotide sequence d. All of these statements are true

d. All of these statements are true

Which of the following is true about operons in general? a. They are found primarily in prokaryotes b. They allow the finest level of gene regulation seen in eukaryotes c. They are composed of a cluster of genes regulated by a single promoter region d. Answers A and C are correct

d. Answers A and C are correct

Retroviruses such as HIV mostly utilize their host's machinery to make more viruses. However, to function properly, retroviruses may also need to incorporate (an) extra enzyme(s) that is/are normally not present in their host's proteome. This/these enzyme(s) is/are: a. Reverse transcriptase b. Integrase c. DNA polymerase III d. Both a and b are correct

d. Both a and b are correct

Which of the following statements is/are correct about sex-linked traits a. Sex-linked traits and mutations can affect males and females b. Sex-linked genetic diseases can affect bacteria c. Sex-linked genes are always found on the X or Y chromosome d. Both a and c are correct

d. Both a and c are correct

hich of the following is/are true about the two DNA strands that form a helix? a. They are antiparallel and complementary to each other b. They are linked to each other by phosphate bonds c. In a gel electrophoresis, DNA would run toward the positive electrode d. Both a and c are correct

d. Both a and c are correct

Steroid hormones such as testosterone and estrogen (both small hydrophobic hormones) are known to bind to which of the following? a. Ligand-gated channels b. G-protein-coupled receptors c. Receptor tyrosine kinases d. Intracellular receptors e. None of the above

d. Intracellular receptors

Which of the following is true about miRNA and siRNA? a. They both allow the regulation of genes expression at the transcriptional level b. They both involve the recruitment of dicer and a RISC complex c. They work by binding to mRNA and preventing its expression d. Only answer B and C are correct

d. Only answer B and C are correct

The regulation of gene expression in eukaryotes and prokaryotes may take place at which of the following levels: a. At the transcriptional level b. At the translational level c. At the post-translational level d. Regulation may take place at all the levels listed above (in a, b, and c)

d. Regulation may take place at all the levels listed above (in a, b, and c)

Which of the following answers describes what happens to the Lac operon when Glucose is high and Lactose is low a. The CAP protein would bind to the CAP site, and the Lac repressor would bind to the operator b. Allolactose would block both the CAP protein and the Lac repressor c. Neither would the CAP protein bind to the CAP site, nor would the Lac repressor bind to the operator d. The CAP protein would not bind to the CAP site, but the Lac repressor would bind to the operator

d. The CAP protein would not bind to the CAP site, but the Lac repressor would bind to the operator

Oxydative phophorylation takes place in which of the following? a. The cytoplasm b. The mitochondrial matrix c. The Kreb's cycle d. The inner mitochondrial membrane

d. The inner mitochondrial membrane

Some bacteriophages have a latent phase in their reproductive cycle during which they integrate their DNA in their host's genome. During this phase, they do not actually reproduce and/or kill their host cell. This phase is known as a. The lytic cycle b. The rhythmic cycle c. The Krebs cycle d. The lysogenic cycle

d. The lysogenic cycle

Which of the following is NOT a common DNA-binding motif for transcription factors? a. Helix-turn helix b. Zinc finger c. Leucine zipper d. beta-pleated sheet

d. beta-pleated sheet

Which statement about ATP is correct? a. ATP serves as an energy "currency" inside the cell b. The reaction of ATP -> ADP + P is coupled to endergonic reactions c. The reaction of ATP -> ADP + P is an exergonic reaction d. The main source of ATP production for an entire plant cells is its mitochondria e. All answers are correct

e. All answers are correct

Which of the following roles is commonly performed by proteins? a. Cytoskeletal support b. Catalysis of chemical reactions c. Formation of transmembrane receptors d. Intracellular transport e. All of the above

e. All of the above

Which of the following best describes the movement of small polar ions such as Na+, Cl-, K+, and Ca2+ across a regular cell membrane? a. The membrane is entirely permeable to these ions, in all conditions b. The membrane restricts the movement of NA+ and K+, but not other ions c. The membrane is totally impermeable to small polar ions d. The membrane allows the movement of small polar ions only if both sides of the membrane are isotonic e. The membrane allows the movement of these ions only through specific channels and pumps

e. The membrane allows the movement of these ions only through specific channels and pumps

Which of the following factors have the ability to denature an enzyme, thereby affecting its functionality? a. Oven temperature b. pH = 14 c. Fridge temperature d. pH = 1 e. a, b, and d can denature enzymes, but not c

e. a, b, and d can denature enzymes, but not c