BIO 183 Fall 2017 Benoit Jacquet Exams 1, 2, and 3 Multiple Choice

The proton-motive force generated during oxidative phosphorylation is used to drive the activation of which of the following? A. ATP synthase B. Ubiquinone C. Cytochromes D. NADH dehydrogenase E. Low-energy electrons

A. ATP synthase

In skeletal muscles, calcium pumps hydrolyze ATP in order to transport calcium against ints concentration gradient, from the cytosol into the sarcoplasmic reticulum (a specialized form of endoplasmic reticulum). This is an example of A. Active transport B. Osmosis C. Passive diffusion D. Facilitated diffusion

A. Active transport

Which of the following is/are a monosaccharide? A. Fructose B. Sucrose C. Lactose D. Cellulose E. Both B and C are monosaccharaides

A. Fructose

In what phase of meiosis do homologous chromosomes line up in the middle of the cell? A. Metaphase 1 B. Anaphase 1 C. Prophase 1 & 2 D. Anaphase 2 E. Metaphase 2

A. Metaphase 1

Which of the following is NOT a reason for mitotic cell division? A. Pollen production in flowers B. Fetal growth C. Tissue repair after injury D. Tumor formation E. All of the above are reasons for mitotic cell division

A. Pollen production in flowers

The molecules represented below are best described as A. Stereoisomers B. Polymers c. Structural isomers D. Dimers E. Enantiomers

A. Stereoisomers

When anaerobic metabolism (fermentation) takes place in mammalian muscle cells, which of the following are produced? A. 36-38 ATPs and lactic acid B. 2 ATPs and lactic acid C. 36-38 ATPs and ethanol D. 2 ATPs and citric acid E. 36 ATPs and lactic acid

B. 2 ATPs and lactic acid

Which of the following structures/molecules would least likely be found in/on a bacterium? A. DNA B. A chloroplast C. A cell wall D. Ribosomes E. Neither A nor C are found in prokaryotes

B. A chloroplast

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 carbohydrates C. A stiff double membrane composed of phospholipids, proteins and nucleic acids D. A double layer made entirely of glycoproteins, glycolipids and cholesterol D. None of the above

B. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins and carbohydrates

Which of the following molecules most closely resembles cAMP? A. A protein B. A nucleotide C. A carbohydrate D. A triglyceride E. Water

B. A nucleotide

Which of the following polysaccharides are you most likely to find in the exoskeleton of a locust (grasshopper)? A. Glycogen B. Chitin C. Starch D. Cellulose

B. Chitin

The protein complexes that hold sister chromatids at their center are known as A. Centrioles B. Cohesins C. Kinetochores D. Spliceosomes E. Centromeres

B. Cohesins

Typically, in a healthy cell, the longest phase of the cell cycle is the A. M phase B. G1 phase C. G2 phase D. S phase E. Cytokinesis

B. G1 phase

Enzymes catalyze chemical reactions by A. Converting substrates into products in their allosteric site B. Lowering the activation energy necessary to start the reaction C. Converting endergonic reactions into exergonic ones D. Both B and C are correct

B. Lowering the activation energy necessary to start the reaction

In eukaryotes, endocytosed solid particles are broken into smaller subunits by A. Vacuoles B. Lysosomes C. Endoplasmic reticulum D. Golgi apparatus

B. Lysosomes

Which of the following factors contribute significantly to high membrane fluidity? A. Long fatty acyl chains on phospholipids B. Presence of double bonds in the fatty acyl chains C. Low temperature D. Presence of leak channels in the membrane

B. Presence of double bonds in the fatty acyl chains

The advantage of using Ca^2+, cAMP or a pyramid-shaped cascade of events downstream of membrane-bound receptors is A. ATP conservation B. Conservation of energy C. Signal amplification and speed D. Signal redundancy E. Enzyme recycling

C. Signal amplification and speed

If you crossed true-breeding tall and short plants, and all of your F_1 generation displayed a uniform mid-sized phenotype, which of the following could you conclude? (Let's assume that all plants are grown in the same controlled environment, and plant size is determined by a single gene) A. The genes encoding for size in these plants follow a pattern of Independent assortment B. The genes encoding for size in these plants show a pattern of incomplete dominance C. The size of these plants is determined by polygenic expression D. The genes encoding for size in these plants show a pattern of codominance E. The genes encoding for size in these plants show a clear pattern of dominance/recessiveness

B. The genes encoding for size in these plants show a pattern of incomplete dominance

The main products of the citric acid cycle (also called Krebs cycle) are A. ATP and citric acid B. Citric acid that is used in oxidative phosphorylation C. ATP, NADH and FADH_2 D. Citric acid and NADPH E. Krebs protein and ATP

C. ATP, NADH and FADH_2

Organisms that generate their own food by converting inorganic molecules into organic ones are called: A. Heterotrophs B. Organotrophs C. Autotrophs D. Chemiotrophs E. Prototrophs

C. Autotrophs

Cyclin-dependent kinases (CDKs) are required for which of the following processes? A. DNA replication (during S-phase) B. DNA transcription C. Cell cycle regulation (check point regulation) D. Sister chromatids separation (during mitosis) E. Cellular communication

C. Cell cycle regulation (check point regulation)

In cases of inheritance when an offspring shows a phenotype that equally represents that equally represents the alleles contributed by each parent (as is seen in the presence of antigens in red blood cells), the pattern of inheritance is known as A. Incomplete dominance B. Epistasis C. Codominance D. Sex-linked inheritance E. Polygenic inheritance

C. Codominance

The 2 main stages of photosynthesis in chloroplasts are A. Photosynthesis and gluconeogenesis B. Oxidative phosphorylation and Citric acid cycle C. Light-dependent reactions and Calvin cycle D. Light and heavy reactions E. Carbon-fixing and Calvin cycles

C. Light-dependent reactions and Calvin cycle

Which of the following proteins acts as an important tumor suppressor? A. SNP B. Ras C. P53 D. MPF E. Gyrase

C. P53

The outer structure of Gram positive bacteria is made mainly of A. Polysaccharides B. Cellulose C. Peptidoglycan D. Chitin E. Proteins

C. Peptidoglycan

Which of the following statements is false regarding DNA and RNA? A. DNA is mostly double-stranded while RNA is mostly single-stranded B. RNA is composed entirely of nucleotides C. The 2 purines found in DNA are adenine and cytosine D. mRNA is only found in eukaryotes

C. The 2 purines found in DNA are adenine and cytosine

What could be said about a tomato skin cell that is placed in deionized water for an extended period of time? A. The cell is placed in a hypertonic environment and is likely to crenate B. The cell is placed in an isotonic environment and will remain unaffected C. The cell is placed in a hypotonic environment is likely to lyse D. We cannot answer this question without additional information regarding tomato skin cells

C. The cell is placed in a hypotonic environment is likely to lyse

During cellular respiration, glycolysis takes place in which of the following? A. The mitochondrial matrix B. The inter-membrane space in mitochondria C. The cytoplasm D. The inner mitochondrial membrane E. In the extracellular environment

C. The cytoplasm

If you discovered a new protein made of a series of alpha helical motifs attached back to back. What would this information suggest to you? A. The protein is most likely very hydrophilic B. The protein is likely to be 4-5 amino acids long C. The protein is likely to be found embedded in some membrane D. The protein exists only in a primary structure E. None of the above can be deduced from the information given

C. The protein is likely to be found embedded in some membrane

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 and trigger a cascade of intracellular signal transduction D. They induce cells to go through apoptosis (cell "suicide") E. They exchange a GDP for a GTP

C. They dimerize and trigger a cascade of intracellular signal transduction

The liver is heavily involved in detoxifying the blood? Based on this statement, which of the following characteristics would you expect to best describe hepatocytes (=liver cells) A. Absence of Golgi apparatus B. Very large nucleus C. Very large smooth endoplasmic reticulum D. Absence of lysosomes E. High concentration of mitochondria

C. Very large smooth endoplasmic reticulum

Match the level of protein structure on the top with the appropriate description below. i. Primary ii. Secondary iii. Tertiary iv. Quaternary w. 3-dimensional shape of polypeptide chain x. linear sequence of amino acids y. assembly of subunits into functional protein z. hydrogen bonding within peptide backbone A. i=x, ii=w, iii=z, iv=y B. i=z, ii=x, iii=y, iv=w C. i=x, ii=z, iii=w, iv=y D. i=y, ii=w, iii=x, iv=z E. i=x, ii=y, iii=z, iv=w

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

The membrane that forms at the end of telophase to separate daughter cells at the end of mitosis in plants is known as A. Cleavage furrow B. A septum C. Cytokinetic constriction D. A cell plate E. Mitotic split

D. A cell plate

The cytoskeleton is composed of which of the following (in order from smallest to largest in size)? A. Proteins, small bones and cartilage B. Actin filaments, microfilaments and intermediate filaments C. Microtubules, intermediate filaments and actin filaments D. Actin filaments, intermediate filaments and microtubules E. Flagella, microtubules and actin filaments

D. Actin filaments, intermediate filaments and microtubules

Steroid hormones such as testosterone and estrogen are known to bind to which of the following? A. Ligand-gated ion channels B. G-protein-coupled receptors C. Receptor tyrosine kinases D. Intracellular receptors E. Voltage-gated ion channels

D. Intracellular receptors

What type of enzyme is usually associated with the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates (i.e. with the phosphorylation of substrates)? A. Phosphatase B. Catalase C. Hydroxylase D. Kinase E. Phosphate dehydrogenase

D. Kinase

In plant cells, most of the ATP to be used by the cell is produced by which of the following? A. The smooth endoplasmic reticulum B. Chloroplasts C. The rough endoplasmic reticulum D. Mitochondria E. None of the above

D. Mitochondria

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 Acetyl Coa D. Pyruvate, ATP and NADH E. NADPH, FADH_2 and ATP

D. Pyruvate, ATP and NADH

Which of the following justifies the need for a cyclic electron flow in the thylakoid membrane A. The calvin cycle uses more NADPH than ATP B. When oxygen is not available, chloroplasts switch to cyclic electron flow C. When CO_2 is not available, chloroplasts make glucose in a cyclic fashion D. The Calvin cycle uses more ATP than NADPH E. When oxygen is not available, the Calvin cycle has to stop

D. The Calvin cycle uses more ATP than NADPH

What is the purpose of stomata on the underside of leaves in green plants? A. They allow the passage of electrons required for photosynthesis B. They allow the movement of water into the leaves when it rains C. They are mainly empty spaces between grana, in chloroplasts D. They allow the movement of CO_2 in and O_2 out of leaves E. They allow the filtration of the air we breathe

D. They allow the movement of CO_2 in and O_2 out of leaves

The fermentation process that leads to the production of ethanol is most likely to take place in A. Bacteria B. C3 plant cells C. Animal muscle cells D. Yeast E. B, C and D are correct

D. Yeast

Which of the following best describes an endergonic reaction? A. ΔG<0 and free energy is released during the reaction B. ΔG>0 and free energy is released during the reaction C. ΔG<0 and the reaction requires the addition of free energy D. ΔG>0 and the reaction requires the addition of free energy E. In the presence of enzymes both B and D could be endergonic

D. ΔG>0 and the reaction requires the addition of free energy

What is the macromolecule illustrated below? A. A protein B. A polysaccharide C. A nucleic acid D. A phospholipid E. A triglyceride

E. A triglyceride

Sister Chromatids move toward the opposite poles of a dividing cell during A. Telophase of mitosis B. Anaphase of meiosis 1 C. Prophase of mitosis D. Prophase of meiosis 1 and 2 E. Anaphase of meiosis 2

E. Anaphase of meiosis 2

Which of the following factors would have the ability to denature a protease commonly found in your stomach (at a pH of approximately 2.0)? A. Placing the enzyme in the fridge (around 4 degrees C) B. Placing the enzyme in a neutral pH environment (pH=7.0) C. Placing the enzyme in an environment containing the wrong salt concentration D. Placing the enzyme in the oven (around 350 degrees C) E. B, C and D could potentially denature the enzyme

E. B, C and D could potentially denature the enzyme

Which of the following is true regarding your mitochondrial DNA? A. It is almost identical to your mother's mitochondrial DNA B. It is virtually identical in all the cells of your body C. It is almost identical to your father's mitochondrial DNA D. In any cell of your body, it is nearly identical to your genomic DNA (the one found in the nucleus) E. Both A and B are correct

E. Both A and B are correct

The scenario below describes which type of enzyme inhibition? A. Non-competitive inhibition B. Allosteric inhibition C. Positive feedback inhibition D. Competitive inhibition E. Both A and B are correct (the are virtually the same thing)

E. Both A and B are correct (the are virtually the same thing)

Which of the following is accurate regarding the disaccharide lactose? A. Lactose is a protein, not a disaccharide! B. Lactose is composed of galactose and glucose C. Lactose is composed of galactose and fructose D. Lactose is sugar found in milk and some of its derivaties E. Both answers B and D are correct

E. Both answers B and D are correct

In the karyotype of a carrot cell, you would expect to see A. More chromosomes than in a human karyotype B. Fewer chromosomes than in a human karyotype C. The same number of chromosomes as in a human karyotype, since carrots are diploid too D. It depends on the stage of the cell cycle during which the comparison is made E. There is no way to predict an organism's chromosome count just by looking at its phenotype

E. There is no way to predict an organism's chromosome count just by looking at its phenotype

Photorespiration can best be explained by which of the following? A. Photorespiration happens when plants use oxygen in chloroplasts instead of mitochondria B. During periods of drought, plants open their stomata to better absorb water through their leaves C. At night or in the dark, C3 plants store CO_2 in the form of organic molecules such as malate D. Some plants utilize light energy to pump oxygen in their leaves E. When temperatures get high, plants close their stomata, and the increased level of O_2 in the mesophyll causes rubisco to work as an oxygenase instead of a carboxylase

E. When temperatures get high, plants close their stomata, and the increased level of O_2 in the mesophyll causes rubisco to work as an oxygenase instead of a carboxylase