1.
The plasma membrane is
Correct Answer
A. A feature of all cells
Explanation
The plasma membrane is a feature of all cells because it is a vital component that surrounds and encloses the cell, acting as a barrier between the cell's internal environment and the external environment. It regulates the movement of substances in and out of the cell, maintains cell shape and integrity, and plays a crucial role in cell signaling and communication. Therefore, every cell, whether prokaryotic or eukaryotic, plant or animal, possesses a plasma membrane.
2.
A graduate student has begun work in a research laboratory that identifies and classifies single-celled organisms in soil and water samples collected from difficult to reach regions of the biosphere. Her first assignment is to finish classifying a group of 10 specimens as prokaryotic or eukaryotic and to determine what tests are necessary to finish the identification. She organized the data collected so far into the following chart.
Presence (+) or Absence (-) of characteristics for Specimens S1-S5 and W1-W5
specimen
designation
cell wall
nucleus
chlorophyll
mitochondria
flagelle
S1
+
n.d.
+
+
-
S2
-
+
-
n.d.
+
S3
n.d.
-
+
-
+
S4
n.d.
n.d.
-
n.d.
-
S5
-
+
+
+
n.d.
W1
+
-
+
n.d.
-
W2
n.d.
+
n.d.
-
+
W3
+
-
-
-
+
W4
+
n.d.
-
+
-
W5
+
n.d.
+
n.d.
-
n.d. = not determined
Which specimens can definitely be classified as prokaryotes from the data presented?
Correct Answer
D. S3, S4, W1, and W3 only
Explanation
Based on the data presented, specimens can be classified as prokaryotes if they have a cell wall, absence of a nucleus, absence of chlorophyll, absence of mitochondria, and absence of a flagellum. From the given data, specimens S3, S4, W1, and W3 meet these criteria and can be classified as prokaryotes.
3.
A cell wall primarily of cellulose is
Correct Answer
C. A feature of plant cells, but not animal cells
Explanation
The correct answer is a feature of plant cells, but not animal cells. This is because cellulose is a structural polysaccharide that provides rigidity and support to plant cells. It forms the cell wall, which is a distinguishing feature of plant cells. Animal cells, on the other hand, do not have a cell wall made of cellulose. They have a flexible cell membrane instead.
4.
A chloroplast is
Correct Answer
C. A feature of plant cells, but not animal cells
Explanation
Chloroplasts are organelles found in plant cells that are responsible for photosynthesis, the process by which plants convert sunlight into energy. They contain chlorophyll, a pigment that captures sunlight and uses it to produce glucose. Animal cells do not have chloroplasts because they obtain energy through other means, such as consuming plants or other animals. Therefore, chloroplasts are a unique feature of plant cells and are not found in animal cells.
5.
The major site of energy production within a cell is the
Correct Answer
E. Mitochondria
Explanation
Mitochondria are known as the "powerhouses" of the cell because they are the major site of energy production. They generate energy in the form of ATP through a process called cellular respiration. This process involves breaking down glucose and other organic molecules to release energy. Mitochondria have their own DNA and are capable of self-replication, indicating their evolutionary origin as independent organisms that formed a symbiotic relationship with eukaryotic cells.
6.
The organelle that modifies and packages the cell's proteins for export is the
Correct Answer
C. Golgi Apparatus
Explanation
The Golgi Apparatus is responsible for modifying and packaging proteins in the cell for export. It receives proteins from the endoplasmic reticulum and modifies them by adding sugars, lipids, or other molecules. It then packages these modified proteins into vesicles and sends them to their final destination, either within the cell or outside of it. The Golgi Apparatus plays a crucial role in protein trafficking and secretion, making it the correct answer for this question.
7.
The organelle that contains hydrolytic enzymes for the digestion of ingested materials is the
Correct Answer
D. Lysosome
Explanation
Lysosomes are organelles that contain hydrolytic enzymes necessary for the digestion of ingested materials. These enzymes break down various substances, including proteins, nucleic acids, carbohydrates, and lipids. Lysosomes play a crucial role in the degradation of cellular waste, the recycling of cellular components, and the defense against invading pathogens. They are responsible for maintaining cellular homeostasis by regulating the breakdown and recycling of molecules.
8.
All of the following are components of the cytoskeleton EXCEPT
Correct Answer
A. Chromosomes
9.
In which part(s) of this cell is the majority of its energy produced with the accompanying use of oxygen and production of carbon dioxide?
Correct Answer
A. I only
Explanation
The correct answer is "I only" because in part I of the cell, which is the mitochondria, the majority of energy is produced through the process of cellular respiration. This process requires oxygen and produces carbon dioxide as a byproduct. The other parts mentioned in the options (II, IV) do not play a direct role in energy production or oxygen utilization.
10.
A graduate student has begun work in a research laboratory that identifies and classifies single-celled organisms in soil and water samples collected from difficult to reach regions of the biosphere. Her first assignment is to finish classifying a group of 10 specimens as prokaryotic or eukaryotic and to determine what tests are necessary to finish the identification. She organized the data collected so far into the following chart.
Presence (+) or Absence (-) of characteristics for Specimens S1-S5 and W1-W5
specimen
designation
cell wall
nucleus
chlorophyll
mitochondria
flagelle
S1
+
n.d.
+
+
-
S2
-
+
-
n.d.
+
S3
n.d.
-
+
-
+
S4
n.d.
n.d.
-
n.d.
-
S5
-
+
+
+
n.d.
W1
+
-
+
n.d.
-
W2
n.d.
+
n.d.
-
+
W3
+
-
-
-
+
W4
+
n.d.
-
+
-
W5
+
n.d.
+
n.d.
-
n.d. = not determined
Which specimens from the data above can definitely be classified as eukaryotes from the data presented?
Correct Answer
D. S1, S2, S5, W2 and W4 only
Explanation
Based on the data presented, the specimens that can definitely be classified as eukaryotes are S1, S2, S5, W2, and W4. This is because they all have a nucleus, which is a characteristic of eukaryotic cells. The presence or absence of other characteristics such as cell wall, chlorophyll, mitochondria, and flagella does not determine whether a specimen is eukaryotic or prokaryotic. Therefore, the correct answer is S1, S2, S5, W2, and W4 only.
11.
A protein that will be exported from the cell would generally travel through which of the following organelles?
In which part(s) of this cell is the majority of its energy produced with the accompanying use of oxygen and production of carbon dioxide?
Correct Answer
D. VI and then III
12.
Which of the following is not a part of the cell theory?
Correct Answer
B. Cells develop through endosymbiosis
13.
Cells that secrete a large amount of lipids have more ______ then cells that do not secrete lipids.
Correct Answer
A. Smooth ER's
Explanation
Cells that secrete a large amount of lipids require a higher amount of smooth ER's compared to cells that do not secrete lipids. Smooth ER's are responsible for lipid synthesis and metabolism, and their increased presence in these cells indicates their role in producing and processing lipids. This is supported by the fact that rough ER's are involved in protein synthesis and lysosomes are involved in waste disposal, while peroxisomes and plastids have different functions unrelated to lipid secretion.
14.
A transport vesicle containing proteins from the RER will travel to the
Correct Answer
A. Cell membrane
Explanation
Transport vesicles containing proteins from the rough endoplasmic reticulum (RER) travel to the cell membrane. This is because the RER is responsible for protein synthesis, and once the proteins are synthesized, they are packaged into transport vesicles to be transported to their final destination. The cell membrane is a crucial site for protein secretion and cell signaling, so it makes sense for the transport vesicles to deliver the proteins there. The other options, such as the cis face of the Golgi Body, smooth ER, and nucleus, are not the typical destinations for proteins from the RER.
15.
If all the lysosomes within a cell suddenly ruptured, what would be the most likely result?
Correct Answer
A. The macromolecules in the cytosol would begin to break down
Explanation
If all the lysosomes within a cell suddenly ruptured, the most likely result would be that the macromolecules in the cytosol would begin to break down. Lysosomes are responsible for the digestion and breakdown of cellular waste and debris. Without intact lysosomes, the cell would lose its ability to properly break down and recycle macromolecules, leading to their accumulation and potential damage to the cell. This can disrupt normal cellular function and potentially lead to cell death or dysfunction.