Question 1

Which of the following organelles produces and modifies polysaccharides that will be secreted?
A) lysosome
B) mitochondrion
C) Golgi apparatus
D) peroxisome

Accepted Answer

The Golgi apparatus is responsible for modifying and sorting proteins and lipids, as well as synthesizing and modifying polysaccharides that will be secreted. The other organelles listed do not have this function. Lysosomes are responsible for breaking down and recycling cellular waste, mitochondria produce ATP for cellular energy, and peroxisomes are involved in lipid metabolism and detoxification reactions.

Question 2

Thylakoids, DNA, and ribosomes are all components found in ________.
A) chloroplasts
B) mitochondria
C) lysosomes
D) nuclei

Accepted Answer

Thylakoids, DNA, and ribosomes are all components found in chloroplasts, which are the organelles responsible for photosynthesis in plant cells.

Question 3

The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence?
A) closing of nuclear pores
B) the inability of the nucleus to divide during cell division
C) a loss of genetic information from chromosomes
D) a change in the shape of the nucleus

Accepted Answer

The nuclear lamina provides structural support to the nucleus and helps maintain its shape. If the lamina were to disassemble, the nucleus would lose its structural integrity, and its shape would change.

Question 4

Which organelle is the primary site of ATP synthesis in eukaryotic cells?
A) lysosome
B) mitochondrion
C) Golgi apparatus
D) peroxisome

Accepted Answer

The mitochondrion is the primary site of ATP synthesis in eukaryotic cells through oxidative phosphorylation. Lysosomes contain enzymes that break down waste materials. The Golgi apparatus is responsible for modifying and sorting proteins. Peroxisomes are involved in lipid metabolism and detoxification.

Question 5

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition?
A) the lysosome
B) the Golgi apparatus
C) the smooth endoplasmic reticulum
D) the rough endoplasmic reticulum

Accepted Answer

Lysosomes are responsible for breaking down and digesting lipids, among other cellular waste products. In Tay-Sachs disease, there is a deficiency in the enzyme necessary to break down a specific lipid, resulting in accumulation of undigested lipids in the lysosomes. Therefore, the lysosome is most likely the defective organelle in Tay-Sachs disease.

Question 6

Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the bound cyanide is likely to be localized within the ________.
A) mitochondria
B) peroxisomes
C) lysosomes
D) smooth endoplasmic reticulum

Accepted Answer

Cyanide binds with one of the enzymes involved in the electron transport chain located in the inner membrane of the mitochondria. Therefore, most of the bound cyanide is likely to be localized within the mitochondria.

Question 7

Which organelle often takes up much of the volume of a plant cell?
A) lysosome
B) central vacuole
C) Golgi apparatus
D) chloroplast

Accepted Answer

The central vacuole in plant cells is a large organelle that can take up to 90% of the cell's volume. This organelle functions in storage, digestion, and maintaining turgor pressure within the cell. Lysosomes are more commonly found in animal cells and are smaller than the central vacuole. The Golgi apparatus and chloroplasts do not usually take up much of the volume of a plant cell.

Question 8

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum?
A) in lysosomes
B) in the Golgi apparatus
C) in the nucleolus
D) in mitochondria

Accepted Answer

Proteins are also produced in mitochondria, which have their own ribosomes and DNA, allowing them to synthesize some of their own proteins.

Question 9

In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and ________.
A) combine the hydrogen with water molecules to generate hydrogen peroxide
B) combine the hydrogen with oxygen molecules to generate hydrogen peroxide
C) combine the hydrogen with hydrogen peroxide to generate oxygen
D) combine the hydrogen with hydrogen peroxide to generate oxygen and water

Accepted Answer

The enzymes in peroxisomes remove hydrogen from toxic molecules and combine it with oxygen to generate hydrogen peroxide (H2O2), which is then further broken down into harmless substances by other enzymes within the peroxisome. Choice A is incorrect because hydrogen peroxide is not formed by combining hydrogen and water molecules. Choice C and D are incorrect because oxygen or water is not generated by combining hydrogen with hydrogen peroxide.

Question 10

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________.
A) a bacterium, but not a eukaryote
B) an animal, but not a plant
C) nearly any eukaryotic organism
D) a plant, but not an animal

Accepted Answer

All of the listed molecules and structures are present in nearly any eukaryotic organism, including protists, fungi, plants, and animals. Bacteria do not have mitochondria or a true nucleus with DNA contained within a membrane, and plants typically have additional structures such as chloroplasts and a cell wall made of cellulose.

Question 11

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?
A) rough endoplasmic reticulum
B) smooth endoplasmic reticulum
C) Golgi apparatus
D) nuclear envelope

Accepted Answer

The smooth endoplasmic reticulum (SER) is primarily involved in detoxification processes, including the metabolism of drugs and the breakdown of toxic substances. Thus, liver cells, which are responsible for detoxification processes, have an abundance of SER. The rough endoplasmic reticulum (RER) is involved in protein synthesis and post-translational modifications, while the Golgi apparatus plays a role in modifying, sorting, and shipping proteins and lipids. The nuclear envelope separates the nucleus from the cytoplasm and regulates the passage of molecules between the two compartments.

Question 12

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following?
A) only in the nucleus
B) only in the nucleus and mitochondria
C) only in the nucleus and chloroplasts
D) in the nucleus, mitochondria, and chloroplasts

Accepted Answer

Radioactively labeled thymine will be incorporated into newly synthesized DNA during cell division. Therefore, the labeled macromolecules will be present in the nucleus. Mitochondria and chloroplasts also have their own DNA and replicate independently, so they will also contain the labeled thymine and show the radiation.

Question 13

Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
A) Prokaryotes cannot secrete proteins because they lack an endomembrane system.
B) Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
C) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.
D) Prokaryotes cannot secrete proteins because they lack rough endoplasmic reticulum.

Accepted Answer

Prokaryotes do not have an endomembrane system like eukaryotes, but they can still secrete proteins. In prokaryotes, proteins that are to be secreted are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane. The proteins are then transported across the membrane and released outside the cell. The mechanism of protein secretion in prokaryotes is different from that in eukaryotes.

Question 14

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules?
A) polysaccharides
B) proteins
C) lipids
D) nucleic acids

Accepted Answer

Ribosomes are responsible for protein synthesis, so a high density of ribosomes in the cytoplasm indicates that the cell is actively producing large amounts of proteins.

Question 15

Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell?
A) rough ER → Golgi → transport vesicle → nucleus
B) Golgi → rough ER → lysosome → transport vesicle → plasma membrane
C) rough ER → Golgi → transport vesicle → plasma membrane
D) rough ER → lysosome → transport vesicle → plasma membrane

Accepted Answer

The most common pathway taken by a newly synthesized protein that will be secreted by a cell is rough ER → Golgi → transport vesicle → plasma membrane. The rough ER is involved in protein synthesis and folding, while the Golgi apparatus modifies, sorts, and packages proteins. The transport vesicles then carry the packaged proteins to the plasma membrane for secretion. Choice C is the only option that follows this pathway.

Question 16

Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. As a result, asbestos fibers accumulate in ________.
A) the Golgi apparatus
B) nuclei
C) peroxisomes
D) lysosomes

Accepted Answer

Asbestos fibers are not degradable by cells, thus they accumulate in lysosomes, which are the cellular organelles responsible for degradation of cellular waste and foreign matter.

Question 17

A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________.
A) store large quantities of water
B) import and export large quantities of protein
C) actively secrete large quantities of protein
D) synthesize large quantities of lipids

Accepted Answer

The smooth endoplasmic reticulum (SER) is involved in lipid synthesis, specifically the synthesis of phospholipids and steroids. Therefore, a cell with a predominance of SER is likely specialized for lipid synthesis.

Question 18

The evolution of eukaryotic cells most likely involved ________.
A) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into chloroplasts
B) endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen-the anaerobic archaea evolved into chloroplasts
C) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria
D) evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum

Accepted Answer

The theory of endosymbiosis proposes that mitochondria evolved from oxygen-using bacteria that were engulfed by larger bacterial cells. Over time, the bacteria evolved into mitochondria as they became integrated and interdependent with the host cell. This theory is supported by several lines of evidence, including similarities between the DNA and biochemistry of mitochondria and bacteria.

Question 19

A cell with a predominance of rough endoplasmic reticulum is most likely ________.
A) producing large quantities of proteins for secretion
B) producing large quantities of proteins in the cytosol
C) producing large quantities of carbohydrates to assemble an extensive cell wall matrix
D) producing large quantities of carbohydrates for storage in the vacuole

Accepted Answer

Rough endoplasmic reticulum (RER) is studded with ribosomes and involved in protein synthesis. A cell with a predominance of RER is most likely producing large quantities of proteins for secretion, which requires the presence of ribosomes on the RER to synthesize and transport the proteins.

Question 20

Which structure below is independent of the endomembrane system?
A) nuclear envelope
B) chloroplast
C) Golgi apparatus
D) plasma membrane

Accepted Answer

Chloroplasts are organelles involved in photosynthesis and are not part of the endomembrane system, which includes the nuclear envelope, Golgi apparatus, and plasma membrane.

Quiz 6: A Tour of the Cell

Which of the following organelles produces and modifies polysaccharides that will be secreted?

Thylakoids, DNA, and ribosomes are all components found in ________.

The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence?

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition?

Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the bound cyanide is likely to be localized within the ________.

Which organelle often takes up much of the volume of a plant cell?

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum?

In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and ________.

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________.

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following?

Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules?

Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell?

A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________.

The evolution of eukaryotic cells most likely involved ________.

A cell with a predominance of rough endoplasmic reticulum is most likely ________.

Which structure below is independent of the endomembrane system?