I. Cell questions
Cell biology practice questions
There are a total of 72 cell biology practice questions, which are important content-oriented in the summary part of this chapter. Click the ‘Answer’ button to see the corresponding answers and explanations, and click the ‘Go back’ button to slove the next questions.
1. Which of the following is (are) disaccharide?
A. Starch
B. Sucrose
C. Maltose
D. Glucose
E. B and C
2. All of the following terms are included in the same macromolecule category EXCEPT .
A. Cholesterol
B. Glycerol
C. Fatty acid
D. Glycogen
E. Steroids
3. Vacuole is an organelle present in most plant cells and it is responsible for many different functions. All of the following statement is true for vacuole, EXCEPT .
A. Vacuole has tonoplasts, which are membranes around central vacuole.
B. Vacuole pumps out excess water and is used for osmotic balance.
C. Plant cells use vacuole as disposal site for metabolic products.
D. Vacuole stores nutrients.
E. All of the above are true statements.
4. Which of the following types of connection is a direct communication of the junction of cytoplasm between two cells?
A. Tight junction
B. Gap junction
C. Plasmodesmata
D. Desmosomes
E. Synaptic junction
5. Which of the following is an INCORRECTLY matched pair?
A. Tight junction: associated membranes between two cells.
B. Desmosomes: anchoring junctions.
C. Plasmodesmata: perforated channels in animal cells.
D. Synaptic signal: transferring neurotransmitter between two nerve cells.
E. Paracrine signal: diffusing signal to local distance.
6. Which of the following statements about cell membranes is INCORRECT?
A. They communicate with other cells.
B. They transport molecules selectively.
C. Major components are proteins and phospholipids.
D. They do not grow.
E. They separate the inside and outside of cells.
7. Breakdown pathway or digestive process to maintain living organisms is called _______________.
A. Catabolism
B. Anabolism
C. Endocytosis
D. Negative feedback
E. Positive feedback
8. Enzymes increase the chemical reaction of a biological catalyst by .
A. Lowering the activation energy
B. Hydrolyzing of reactants
C. Changing direction
D. Increasing pH of environment
E. Increasing temperature of environment
9. Which of the following is NOT a product of glycolysis?
A. Pyruvate
B. ATP
C. NADH
D. H+
E. FADH2
10. Which of the following is NOT correctly matched?
A. Hexokinase: production of glucose-6-phosphate
B. Phosphoglucoisomerase: production of fructose-6-phosphate
C. Isomerase: production of glyceraldehydes-3-phosphate
D. Enolase: production of 2-phosphoglycerate
E. Pyruvate kinase: production of pyruvate
11. Which of following elements is NOT a component of nucleotide?
A. Carbon
B. Sulfate
C. Phosphate
D. Oxygen
E. Hydrogen
12. All of the following statements apply to nucleic acids EXCEPT ________________.
A. These molecules store genetic information.
B. Deoxyribose and ribose sugars are components of nucleic acids.
C. Even one base mutation in a DNA sequence causes serious problems in making proteins.
D. DNA is a single stranded molecule and RNA is a double stranded molecule.
E. There are hydrogen bonds and phosphodiester bonds in DNA sequences.
13. Which combination of the following describes RNA?
13. Which combination of the following describes RNA?
I. Ribose sugar II. A, G, C, T III. Single strand for codes of proteins IV. Phosphodiester bond |
A. I and II only
B. III and IV only
C. I, II, and III
D. I, III, and IV
E. All of the above
14. Which of the following about endocrine is FALSE?
A. Long distance signal
B. Diffusing signal through extracellular matrix to target cell
C. Signals are hormones
D. Transferring signals by blood cells
E. All are correct
15. Which of the following does NOT apply to cell surface reception?
A. Ion channel linked receptors
B. G-protein linked receptors
C. Binding steroid hormone receptors
D. Receptor tyrosine kinases
E. Receptors on plasma membrane
16. Which of the following moves against the concentration of substances?
A. Osmosis
B. Facilitated diffusion
C. Sodium-potassium pump of axon
D. Active transport
E. C and D
17. Which of the following statements about hypotonic conditions are true?
I. The water potential is higher outside the cell than inside the cell. III. Plants become to be plasmolyzed. IV. Organisms that lack cell walls, such as mycoplasma bacteria, are subject to lysis. |
A. I and II
B. I and IV
C. II and III
D. I, III, and IV
E. All of the above
18. Which of the following is an INCORRECT statement?
A. When animals move, heat energy emits and entropy increases.
B. Converting chemical energy into kinetic energy after digestion is an example of the first law of thermodynamics.
C. Reversal of internal conditions against outside environment change is called positive feedback.
D. Most homeostatic animals are controlled by negative feedback.
E. Building complicated molecules from simple molecules is called anabolic pathway.
19. Which of the following statements about enzymes is (are) true?
I. Enzymes are reusable after finishing catalytic activities. II. The components of enzymes are mainly proteins. III. Cooking at high temperatures can kill bacteria because their enzymes are denatured. IV. All enzymes are quaternary structures. |
A. I only
B. I and II
C. I, II, and III
D. II, III, and IV
E. All of the above
20. Which of the following statements about enzymes is FALSE?
A. The activity of enzymes cannot change ΔG and Keq.
B. Each enzyme has a certain optimum temperature and pH.
C. The activity of enzymes is influenced by the concentration of products.
D. A change in the active site causes a decrease in the rate of enzymes immediately.
E. Pepsin, trysin, and lactase are active enzymes.
21. In chloroplasts, which of the following molecules can be produced in the light dependent reaction?
A. NADPH, NADH, H2O
B. NADH, glucose, CO2
C. NADPH, ATP, O2
D. NADPH, glucose, CO2
E. All of the above
22. Which of the following is a correct statement?
A. O2 is the final electron acceptor in the electron transport chain during photosynthesis.
B. H2O splits into O2 and 2H+ in the photosystem I.
C. The product of the photosystem II is NADPH and the product of the photosystem I is ATP.
D. During ATP synthesis in chloroplasts, H+ ions are diffused from lumen to stroma.
E. When the electrons move through the electron transport chain in the thylakoid membrane, ADP moves from lumen to stroma of the chloroplast.
23. Which of the following statements concerning cellular respiration is true?
A. During glycolysis, one glucose molecule is converted into two pyruvate molecules in the matrix of the mitochondria.
B. During fermentation, glucose molecules are converted into ethanol and this process does not produce energy.
C. Lactate and ethanol are made in the cytoplasm in the presence of oxygen.
D. Pyruvate is converted into acetyl CoA to be used in the Krebs cycle.
E. The Krebs cycle works at anaerobic metabolism in mitochondria.
24. Which one is true during fermentation?
A. NADH is oxidized to NAD+
B. NADPH is oxidized to NADP+
C. FAD+ is reduced to FADH2
D. NAD+ is reduced to NADH
E. None of the above
25. Phospholipids are a major component of cell membranes and form bilayers because their structures are _______________.
A. Lipid
B. Amino acid
C. Hydrophobic
D. Amphipathic
E. Hydrophilic
26. _______________ molecules consist of four fused carbon rings and function in keeping fluids inside animal cell membranes.
A. Phospholipid
B. Triacylglycerol
C. Steroids
D. Cellulose
E. Chitin
27. _______________ are hollow rods of tubulin with a 9+2 arrangement structure, which function for cell motility by cilia and flagella and ______________ are fibrous proteins in nuclear lamina or keratins.
A. Microfilaments, microtubules
B. Microtubules, intermediate filaments
C. Microtubules, microfilaments
D. Microfilaments, intermediate filaments
E. None of the above
28. Proteins that are activated by accepting phosphate groups are a result of _______________.
A. Protein kinase
B. Protein phosphatases
C. Signal pathway
D. Intracellular reception
E. A and B
29. Which of the following statements about G-protein signaling pathway is FALSE?
A. First messenger is bound to G-protein linked receptor.
B. GTP activates G protein.
C. Activated G protein activates Adenylyl cyclase.
D. Second messenger, Cyclic AMP, activates protein kinase A.
E. All are correct.
30. Which of the following does NOT apply to diffusion?
A. Molecule movement from high concentration area to low concentration area
B. Movement of O2 and CO2 through cell membrane
C. Second law of thermodynamics
D. Diffusion of water, also called osmosis
E. All are correct.
31. All of the following are endocytosis EXCEPT _______________ .
A. Autophagy
B. Phagocytosis
C. Pinocytosis
D. Secretions
E. A and D
32. Enzymes can be denatured by _____________ .
A. Changing condition of pH
B. Increasing temperature
C. Decreasing temperature
D. A and B
E. All of the above
33. Which of the following molecule is the product of the Calvin cycle?
A. ATP
B. G3P
C. NADPH
D. NADP
E. CO2
34. Rubisco .
A. Binds to RuBP and CO2 to make PGA
B. Lowers the activation energy
C. Supplies energy to increase the speed of reaction
D. Binds to acetyl CoA and Oxaloacetate to make citrate
E. A and B
35. The reaction below occurs in which of the following organelles?
 |
A. Chloroplast
B. Mitochondria
C. Ribosome
D. Lysosome
E. Nucleus
36. Which of the following applies to fermentation?
A. Reaction in cytosol
B. Aerobic respiration
C. Ethanol production in muscle cells
D. Acetyl CoA production
E. Regeneration of NADP+
37. The following are common features of both mitochondria and chloroplasts EXCEPT _______________.
A. Found in plant cells
B. Structure with double membranes
C. Containing ribosomes and DNA
D. Evolution theory of bacterial symbiosis
E. Found in aerobic eukaryotic cells
38. Which of the following statements is NOT true about protein?
A. Amino group, carboxyl group, and hydrogen are major components of amino acid.
B. 2o different kinds of amino acid are found in proteins.
C. Heating and pH change cause protein to lose its structure and become inactive.
D. Amino acids are linked by dehydration and become polypeptides.
E. Functional macromolecules are tertiary structures that are formed by hydrogen bonds, disulfide bonds, hydrophobic interaction, and ionic bonds.
39. _______________ is formed only by peptide bonds, and _______________ has the major shapes of alpha helixes and beta-pleated sheets.
A. Primary structure, secondary structure
B. Secondary structure, tertiary structure
C. Tertiary structure, quaternary structure
D. Tertiary structure, secondary structures
E. Secondary structure, primary structure
40. Endomembrane systems are composed of all of the following cellular structures EXCEPT _______________.
A. Transport vesicles
B. Smooth ER
C. Golgi complex
D. Lysosomes
E. Peroxisomes
41. Which of the following organelles may be present in the both prokaryotic and eukaryotic cells?
A. Ribosome
B. Cytoskeleton
C. Nucleoid
D. Centriole
E. A and B
42. Which of the following is a correctly matched pair?
A. Pinocytosis: particles engulfed by membrane
B. Phagocytosis: liquid engulfed by membrane
C. Receptor-mediated endocytosis: molecules engulfed using membrane receptors
D. Endocytosis: stuff ejected outside membrane
E. B and C
43. Which of the following exergonic reaction of enzymes is FALSE?
A. Substrates contain more energy than products.
B. Free energy is released.
C. Water and carbohydrates are converted into glucose and oxygen.
D. Entropy is increased.
E. During phosphorylation ADP is generated by exergonic reaction.
44. Which of the following statements about chlorophyll are true?
I. The conversion of light energy to chemical energy occurs at chlorophyll. III. Since the hydrocarbon tail structure of chlorophyll is similar to fatty acid, the hydrocarbon tail can be embedded into thylakoid membranes. IV. The porphyrin ring at the head of chlorophyll has a Mg molecule. |
A. I and II
B. II and IV
C. I, II, and III
D. II, III, and IV
E. All are true
45. Which of the following pigments reflects mostly blue-green light as a primary pigment?
A. Chlorophyll a
B. Chlorophyll b
C. Carotenoid
D. A and B
E. All of the above
46. What is the original source of electron in the photosynthesis?
A. Light
B. Carbon hydrate
C. Water
D. Oxygen
E. NADPH
47. Which of the following statements about cellular respiration are true?
I. This respiration occurs in both plant and animal cells. |
A. I and II
B. II and III
C. I, II, and III
D. II, III, IV
E. All of the above
48. Amino acid and glycerol are converted into glucose. This metabolic pathway is called _______________.
A. Gluconeogenesis
B. Glycolysis
C. Fermentation
D. Anaerobic respiration
E. Citric acid cycle
49. Oxygen is the final source for acceptance of electrons. In which stage does this happen?
A. Citric acid cycle
B. Calvin cycle
C. Electron transport system in mitochondria
D. Electron transport system in chloroplasts
E. Glycolysis
50. Which of the following lists the normal sequence of the scientific method?
A. Hypothesis → observation → experimentation → conclusion
B. Predictions → experimentation → hypothesis → conclusion
C. Predictions → hypothesis → observation → conclusion
D. Observation → hypothesis → predictions → experimentation
E. Observation → predictions → hypothesis → conclusion
51. All of the following statements are about smooth endoplasmic reticulum EXCEPT _______________.
A. Liver cells possess large amounts of smooth endoplasmic reticulum.
B. Ribosomes are bound in smooth ER for protein synthesis.
C. This organelle participates in lipid synthesis and detoxification.
D. Calcium storage is one of the functions of smooth ER.
E. This organelle is involved in the endomembrane system.
52. Which of the following does (do) NOT have a double membrane?
A. Nucleus
B. Lysosome
C. Chloroplast
D. Mitochondria
E. B and C
53. All of the following statements about enzymes are true EXCEPT _______________.
A. Allosteric enzymes can produce products by binding activator at the allosteric site.
B. Cooperative enzymes can amplify the activity of active sites by binding one substrate to an active site.
C. Anabolic pathway can be controlled by feedback inhibition.
D. Inhibitors are bound to the active site and substrates are bound to the allosteric site during competitive inhibition.
E. Enzymes with non-competitive inhibition have allosteric sites to bind inhibitors.
54. An example of a C4 plant is _______________.
A. Rice
B. Sugarcane
C. Pineapple
D. Rose tree
E. Soybeans
55. All of the following apply to CAM plants EXCEPT _______________.
A. Cacti
B. Adaptation in arid conditions
C. Spatial separation
D. Entering CO2 into stomata during night
E. Working of Calvin cycle with closed stomata during day
56. During cellular respiration, in which reaction is the greatest amount of ATP produced?
A. Glycolysis
B. Fermentation
C. Krebs cycle
D. Electron transport
E. Production of Acetyl CoA
57. Which of the following is NOT produced in cytoplasm during cellular respiration?
A. Ethanol
B. Acetyl CoA
C. ATP
D. Lactate
E. Pyruvates
58. Which of the following is NOT formed by dehydration reaction?
A. Polysaccharide
B. Disaccharide
C. Protein
D. Amino acid
E. Fat
59. Which of the following applies to prokaryotic cells?
A. Mitotic and meiotic division
B. Larger than eukaryotic cells
C. Nucleus
D. Lack internal membranous organelles
E. Sexual reproduction by binary fission
60. An organelle that produces ATP but is not contained in animal cells is likely to have all of the following features EXCEPT _______________.
A. Photosynthesis
B. Double membrane
C. Stroma
D. Matrix
E. Chlorophyll
61. Which of the following is NOT contained in the thylakoid disk?
A. Chlorophyll
B. Photosystem II
C. Thylakoid membrane
D. Lumen
E. Stroma
62. Which of the following products is INCORRECTLY matched to the reaction?
A. ATP: Electron transport chain
B. NADPH: Photosystem I
C. PGA: Calvin cycle
D. O2: Photosystem II
E. H+: Photosystem I
63. Which of the following statements are true?
I. During fermentation the final electron acceptor is not oxygen but organic molecules. |
A. I and II
B. II and III
C. I, III, and IV
D. II, III, and IV
E. All of the above
64. All of the following are produced from cellular respiration EXCEPT ______________.
A. ATP
B. Carbon dioxide
C. Water
D. PGAL
E. All of the above
65. Which characteristics do chloroplasts and mitochondria have in common?
A. Single membrane
B. Aerobic cellular respiration
C. CO2 production
D. Ribosome and DNA
E. NADPH production
66. Which of the following does NOT apply to cells?
A. The smallest unit of life
B. Basic units of all living organisms
C. Diverse forms of living things
D. All cells come from other cells
E. None of the above
67. Which of the following is a messenger causing calcium to activate various proteins directly?
A. Signal molecule
B. Activated G protein
C. PIP2
D. IP3
E. DAG
68. Which of the following is a reduced reaction?
A. 6CO2 from C6H12O6
B. NADPH from NADP+
C. CO2 from CH4
D. 6O2 from 6H2O
E. All of the above
69. Which of the following is NOT related to oxidative phosphorylation?
A. Electron transport chain
B. Chemiosmosis
C. Outer mitochondrial membrane
D. ATP synthesis
E. Ubiquinone and cytochrome C
70. Which of the following about the citric acid cycle is NOT true?
A. This reaction happens in stroma.
B. The combining acetyl CoA with oxaloacetate produces citrate.
C. CO2, NADH, ATP, and FADH2 are produced.
D. This happens in the aerobic condition.
E. All are true.
71. Which of the following does NOT belong to mitochondria?
A. Grana
B. Double membrane
C. Krebs cycle
D. Cristae
E. Matrix
72. Choose the correct statement(s).
I. The locomotion of H+ across a membrane through ATP synthase is active transport. |
A. I only
B. I and II
C. II and III
D. II, III, and IV
E. All of the above
Answers
1. E
Monosaccharides are glucose, fructose, galactose, and ribose. Disaccharides are sucrose, maltose, and lactose. Polysaccharides are starch, glycogen, cellulose, and chitin.
2. D
All of the above except D belong to the subcategory of lipid. Glycogen polymerized glucose in animals belongs to the subcategory of sugar.
3. E
Main functions of vacuole are the storage of nutrients and waste molecules. Also, it is involved in the functions of keeping internal pH and osmotic balance.
4. B
Gap junction, which consists of pored membrane proteins, communicates with heart muscle cells and animal embryo cells.
7. A
Metabolism means the energy property of the chemical reaction to maintain a living organism. Metabolism has two pathways, the catabolic pathway and the anabolic pathway. Anabolic pathway is building complicated molecules from simple units.
8. A
Enzymes are biological catalysts, increasing the chemical reaction by lowering the activation energy without being used up.
9. E
During glycolysis, one glucose is converted into two pyruvates in cytosol. 2ATP are invested and 4ATP are harvested, so net 2ATP are harvested. Other harvesting products are 2NADH, 2H+, 2H2O.
11. B
The elements of protein are C, H, O, N, S and the elements of nucleotide are C, H, O, N, P. S (sulfate) is the least abundant element in living cells.
13. D
RNA and DNA strands are nucleic acids but RNA has unique characteristics, which are ribose sugar, uracil of bases, and single strand. Both DNA and RNA strands are linked by phosphodiester bonds.
14. B
Endocrine is the release of extracellular signals (hormones) into blood cells. Paracrine is local distance and diffusing signal through extracellular matrix to near target cells.
15. C
Receptors binding hydrophobic hormones such as steroid hormones are found inside of a cell and called intracellular reception.
16. E
Active transport means movement of substances from a low concentration area to a high concentration area such as sodium-potassium or electrogenic pump.
17. B
In hypotonic conditions water moves from outside the cell to inside the cell, and plants become turgid.
18. C
Reversal of internal conditions against outside environment change is called negative feedback. Positive feedback is change of internal conditions in the same direction as outside environmental change.
20. C
The activity of enzymes is influenced by the concentration of reactants, pH level, and temperature.
21. C
The light dependent reactions occur at the thylakoid membrane in chloroplasts and produce O2, ATP, and NADPH. The light independent reactions occur in stroma and produce glucose.
22. D
O2 is the final electron acceptor in the electron transport chain during cellular respiration. H2O splits into O2 and 2H+ in the photosystem II. The final product of the photosystem II is ATP and the product of the photosystem I is NADPH. During ATP synthesis in chloroplasts, H+ ions are diffused from lumen (thylakoid space) to stroma as an outward reaction, while during ATP synthesis in mitochondria, H+ ions are diffused from intermembrane space to mitochondrial matrix as an inward reaction. ADP can not move through the thylakoid membrane.
23. D
Glycolysis happens in the cytosol of cells. During fermentation process, lactate and ethanol are made and ATP energy is produced in the absence of oxygen. Krebs cycle works at aerobic metabolism in mitochondria.
25. D
Cell membranes are composed of phospholipids forming bilayers (hydrophilic and hydrophobic).
26. C
Phospholipid forms amphipathic bilayers of cell membranes. Triacylglycerol is a fat molecule, which is composed of glycerol and three fatty acid units. Cellulose is connected by microfibrils and is a component of cell walls of plants. Chitin, a nitrogenous sugar,is an important component of the cell walls of fungi.
27. B
Microtubules are components of centrosomes and centrioles. Microfilaments are two intertwined stranded structures used in myosin and actin filaments in muscle cells. Intermediate filaments have tensile strength from fibrous proteins and are used in protein subunits (keratin filaments) or formation of unclear lamina.
28. A
Active or inactive enzymes are regulated by phosphorylation, which involves protein kinases and phosphatases. Proteins that are inactivated by losing phosphate groups are a result of protein phosphatases.
31. E
Endocytosis means the movement of liquid, particles, and molecules by pinocytosis, phagocytosis, and receptor-mediated endocytosis. Autophagy means breaking down damaged organelles by lysosomes containing hydrolytic enzymes. Secretion means the movement of molecules from the inside to the outside of a cell.
33. B
The product of the Calvin cycle is G3P (glucose) and the products of the Krebs cycle are ATP, CO2, NADH, FADH.
34. E
Rubisco enzyme is used in the Calvin cycle to bind to RuBP and CO2 to make PGA, but acetyl CoA, which is combined with oxaloacetate acid to become citrate, is used in the citric acid cycle.
36. A
Fermentation is anaerobic respiration in cytosol. During fermentation ethanol, lactate, and NAD+ are produced. Production of lactate occurs in muscle cells. The production of Acetyl CoA happens in mitochondria. Regeneration of NADP+ occurs in chloroplasts.
37. E
All statements of above are common features of both mitochondria and chloroplasts except E. Mitochondria requires O2 as final electron receptors.This is found only in aerobic cellular conditions.
39. A
Primary structure uses only peptide bonds to form the linear of amino acids sequences, and secondary structure forms alpha helix and beta-pleated sheets using hydrogen bonds. Tertiary structure is formed by disulfide bonds, ionic bonds, hydrophobid interaction, and hydrogen bonds.
40. E
Endomembrane systems are involved in transport of protein and metabolic functions. This system contains nuclear envelope, rough ER, smooth ER, transport vesicles, golgi complex, lysomes, vacuoles, and cell membrane. Peroxisomes are not part of endomembrane system.
41. E
Ribosomes, cytoskeletons, and cell walls are present in both prokaryotic and eukaryotic cells. Nucleoids may be present in only prokaryotic cells. Centrioles and lysosomes appear in eukaryotic animal cells.
42. C
Pinocytosis engulfs liquid by the membrane and phagocytosis engulfs particles by the membrane. Endocytosis is the movement of large molecules into the membrane and exocytosis is the ejection of stuff outside the membrane.
43. C
The reaction of converting water and carbohydrates into glucose and oxygen is an endergonic reaction, whereas the opposite of this reaction is an exergonic reaction.
45. A
Chlorophyll is a primary pigment, which reflects blue-green light and absorbs violet-blue and red light. Chlorophyll b reflects green-yellow light as an accessory pigment. Carotenoid is also an accessory pigment and reflects yellow-red light.
46. C
The original source of electron is H2O, which is split into electron, hydrogen, and oxygen at photosystem II.
50. D
Correct steps on the scientific method:
Observation → hypothesis → predictions → experimentation → controls → conclusion
52. B
Chloroplast, mitochondria, and nucleus have a double membrane. Lysosome, smooth and rough ER, golgi complex, and peroxisome have a single membrane. Centriole and ribosome do not have membrane.
53. D
During competitive inhibition, since the inhibitor is bound to the active site the substrate cannot be bound to the active site. Substrates always can be bound to the active site.
54. B
C4 plants adapted in hot and dry conditions have spatial separations to fix CO2 in mesophyll cells for the working of the Calvin cycle in bundle sheath cells such as sugarcane and corn.
55. C
Spatial separation occurs in C4 plants. CAM plants have temporal separation (day and night) that CO2 enters into stomata during the night and then the Calvin cycle works with closed stomata during the day.
56. D
One glucose produces 2ATP in glycolysis, 2ATP in the citric acid (Krebs) cycle, and 32-34ATP in the electron transport chain.
57. B
Acetyl CoA is produced inside mitochondria membranes. In the cytoplasm ATP and pyruvates are produced by glycolysis, and ethanol and lactate are produced by fermentation.
58. D
Amino acid, a subunit of protein, is composed of an amino group, a carboxyl group, a functional group, α carbon, and hydrogen. It is not formed by dehydration synthesis.
59. D
Eukaryotic cells reproduce by mitotic and meiotic division and have internal membranous organelles such as nucleus and mitochondria. Prokaryotic cells reproduce asexually by binary fission and lack internal membranous organelles such as nucleoid and ribosome.
60. D
Chloroplasts synthesizing ATP do not belong to animal cells. Inside the double membranes of mitochondria is the called matrix, which is found in both animal and plant cells.
61. E
Substructures of chloroplasts are grana and stroma. The thylakoid disk, a single structure of the granum, contains thylakoid membrane and lumen. The thylakoid membrane contains photosystems and chlorophyll.
62. E
H2O, a source of electrons, is broken down into H+ and O2 at photosystem II. The final product of photosystem II is ATP, which is derived from the electron transport system.
65. D
Mitochondria and chloroplast are double membranes. Aerobic cellular respiration and CO2 production are characteristics of mitochondria only. Only chloroplasts produce NADPH.
67. D
The second messenger IP3 derived from PIP2 is bound to IP3-gated calcium channel to flow out Ca2+ from Endoplasmic Reticulum to cytosol.
68. B
Reduction is gaining hydrogen (electron) or losing oxygen, whereas oxidation is losing hydrogen (electron) or gaining oxygen. A, C, and D are gaining oxygen, thus they are oxidation.
69. C
Oxidative phosphorylation is the process of electron transport and chemiosmosis. ATP synthesis happens in chemiosmosis, which is located at thylakoid membrane in chloroplast and at inner membrane in mitochondria. Ubiquinone and cytochrome C carry electrons in the electron transport chain.
70. A
The citric acid cycle, also called the Krebs cycle, happens at the matrix of mitochondria. The Calvin cycle reaction occurs in stroma of chloroplasts.
72. C
The locomotion of H+ across a membrane through ATP synthase in chloroplast and mitochondrion is facilitated diffusion. The direction of H+ movement across the mitochondria membrane is from intermembrane space into matrix.