1.
Where does glycolysis take place?
Correct Answer
A. Cytoplasm
Explanation
Glycolysis is a metabolic pathway that breaks down glucose into pyruvate molecules. It is the first step in cellular respiration and occurs in the cytoplasm of cells. The cytoplasm is the fluid-filled region outside the cell nucleus where many cellular processes take place. Therefore, glycolysis takes place in the cytoplasm.
2.
Which of the following statements best describes cellular respiration?
Correct Answer
C. Carbon-based molecules from food and oxygen are used to make ATP.
Explanation
Cellular respiration is the process by which cells convert carbon-based molecules from food and oxygen into ATP, the energy currency of the cell. This process occurs in the mitochondria and involves a series of chemical reactions that release energy. The other options are incorrect because they do not accurately describe the process of cellular respiration.
3.
Which of the following are end products of glycolysis?
Correct Answer
D. Pyruvate, NADH, and ATP
Explanation
The correct answer is pyruvate, NADH, and ATP. Glycolysis is the process in which glucose is broken down into pyruvate. NADH and ATP are also produced during glycolysis as a result of various enzymatic reactions. This process occurs in the cytoplasm of cells and is the first step in both aerobic and anaerobic respiration.
4.
What is the main function of the Krebs cycle?
Correct Answer
C. Producing molecules that carry high-energy electrons to the electron transport chain
Explanation
The main function of the Krebs cycle is to produce molecules that carry high-energy electrons to the electron transport chain. This cycle, also known as the citric acid cycle, occurs in the mitochondria and is an essential part of cellular respiration. During the Krebs cycle, acetyl-CoA is oxidized, resulting in the production of NADH and FADH2. These molecules carry high-energy electrons that are then used in the electron transport chain to generate ATP, the cell's main source of energy.
5.
What is the function of oxygen in cellular respiration?
Correct Answer
B. To pick up electrons at the end of the electron transport chain
Explanation
Oxygen plays a crucial role in cellular respiration by picking up electrons at the end of the electron transport chain. During cellular respiration, electrons are passed along the electron transport chain, creating a flow of energy. Oxygen acts as the final electron acceptor, combining with the electrons and hydrogen ions to form water. This process is essential for the production of ATP, the main energy currency of the cell. Without oxygen, the electron transport chain would not be able to function properly, leading to a decrease in ATP production and cellular energy.
6.
Which of the following types of organisms uses cellular respiration for their cellular energy needs?
Correct Answer
A. Eukaryotes
Explanation
Eukaryotes use cellular respiration for their cellular energy needs. Cellular respiration is the process by which cells convert glucose and oxygen into carbon dioxide, water, and ATP (adenosine triphosphate), which is the energy currency of cells. Eukaryotes include organisms such as plants, animals, fungi, and protists. These organisms have complex cellular structures, including a nucleus and membrane-bound organelles, which allows them to carry out cellular respiration efficiently. In contrast, prokaryotes, such as bacteria, lack a nucleus and organelles, and they have different mechanisms for obtaining energy.
7.
Which process breaks down sugars to make ATP when oxygen is present?
Correct Answer
B. Cellular respiration
Explanation
Cellular respiration is the correct answer because it is the process by which cells break down sugars, such as glucose, in the presence of oxygen to produce ATP (adenosine triphosphate), which is the energy currency of the cell. This process occurs in the mitochondria of eukaryotic cells and involves three main stages: glycolysis, the Krebs cycle, and oxidative phosphorylation. Anaerobic respiration, on the other hand, occurs in the absence of oxygen and produces less ATP, while photosynthesis is the process by which plants convert sunlight into energy and does not involve the breakdown of sugars.
8.
The part of cellular respiration in which glucose is broken down is called
Correct Answer
D. Glycolysis.
Explanation
Glycolysis is the correct answer because it is the initial step in cellular respiration where glucose is broken down into pyruvate. This process occurs in the cytoplasm of the cell and does not require oxygen. Photosynthesis is the process by which plants convert sunlight into energy, while aerobic respiration and electron transport occur later in cellular respiration and require oxygen.
9.
Which organelle converts molecules from the food you eat into usable energy?
Correct Answer
C. Mitochondrion
Explanation
The mitochondrion is the correct answer because it is responsible for converting molecules from the food we eat into usable energy in the form of ATP (adenosine triphosphate) through cellular respiration. This organelle is often referred to as the "powerhouse" of the cell because it generates the majority of the cell's energy. The Golgi apparatus is involved in packaging and modifying proteins, the chloroplast is responsible for photosynthesis in plant cells, and the lysosome contains enzymes for digesting waste materials.
10.
In the electron transport chain, hydrogen ions are pumped across the mitochondrial membrane. What provides the energy to operate the protein pumps?
Correct Answer
A. Electrons
Explanation
Electrons provide the energy to operate the protein pumps in the electron transport chain. As electrons pass through the chain, energy is released and used to pump hydrogen ions across the mitochondrial membrane. This creates a concentration gradient, which drives the production of ATP, the cell's main energy source. Oxygen is the final electron acceptor in the chain, while carbon dioxide is not directly involved in the energy generation process.
11.
What enzyme is located at the end of the electron transport chain?
Correct Answer
A. ATP synthase
Explanation
ATP synthase is the correct answer because it is the enzyme located at the end of the electron transport chain. This enzyme is responsible for synthesizing ATP, the energy currency of the cell, by using the energy from the movement of protons down their concentration gradient. This process occurs in the inner mitochondrial membrane in eukaryotes and the plasma membrane in prokaryotes. ATP synthase acts as a molecular motor, using the energy from the proton gradient to rotate and generate ATP.
12.
Which of the following stages occurs in the mitochondrial matrix?
Correct Answer
A. The cirtic acid cycle
Explanation
The correct answer is the citric acid cycle. The citric acid cycle, also known as the Krebs cycle, occurs in the mitochondrial matrix. It is a series of chemical reactions that takes place in the presence of oxygen and is an important part of cellular respiration. During this cycle, acetyl-CoA is oxidized and produces ATP, NADH, FADH2, and carbon dioxide as byproducts. This cycle plays a crucial role in the generation of energy in the form of ATP for the cell.
13.
The three-carbon molecule formed by glycolysis is ___.
Correct Answer
A. Pyruvate
Explanation
Glycolysis is the metabolic pathway that breaks down glucose into pyruvate. Pyruvate is a three-carbon molecule that is formed as the end product of glycolysis. Therefore, the correct answer is pyruvate.
14.
In the diagram to the right, what is structure A?
Correct Answer
A. Folded inner membrane
Explanation
The correct answer is folded inner membrane. In the diagram, structure A appears as a series of folded membranes within the mitochondria. This structure is characteristic of the inner membrane of the mitochondria, which is responsible for carrying out various metabolic reactions and generating ATP through oxidative phosphorylation. The folding of the inner membrane increases its surface area, allowing for more efficient ATP production.
15.
In the diagram to the right, what is structure B?
Correct Answer
B. Mitochondrial matrix
Explanation
Structure B in the diagram refers to the mitochondrial matrix. The mitochondrial matrix is the innermost compartment of the mitochondria and is surrounded by the folded inner membrane. It contains a gel-like substance and is the location where many metabolic reactions occur, including the citric acid cycle and fatty acid oxidation. The matrix also contains DNA, ribosomes, and enzymes necessary for the production of ATP through aerobic respiration.
16.
Which of the following is a feature found only in animal cells?
Correct Answer
D. Centriole
Explanation
Centrioles are cylindrical structures found only in animal cells. They play a crucial role in cell division by organizing the microtubules that form the spindle fibers. Centrioles are not present in plant cells, making them a unique feature of animal cells. Central vacuoles, mitochondria, and nuclei, on the other hand, are found in both animal and plant cells.
17.
A membrane-bound sac that contains digestive enzymes is a ...
Correct Answer
C. Lysosome.
Explanation
A lysosome is a membrane-bound sac that contains digestive enzymes. These enzymes break down waste materials, cellular debris, and foreign substances in the cell. Lysosomes play a crucial role in cellular digestion and recycling, as well as in defending the cell against harmful invaders. They are responsible for maintaining the balance of nutrients and eliminating waste products, making them essential for the overall functioning and health of the cell.
18.
Which of the following is not found in a plant cell?
Correct Answer
D. Flagella
Explanation
Flagella are not found in plant cells. Flagella are whip-like structures that are responsible for cell movement in some organisms, such as bacteria and sperm cells. Plant cells do not have flagella, as they have a rigid cell wall and are typically immobile. Instead, plant cells have specialized structures called cilia, which are shorter and more numerous than flagella, and are involved in processes such as cell signaling and nutrient uptake.
19.
Which of the following is a feature found only in plant cells?
Correct Answer
A. Central vacuole
Explanation
The central vacuole is a feature found only in plant cells. It is a large, fluid-filled organelle that occupies most of the cell's volume. The central vacuole helps maintain the cell's shape and provides support to the plant. It also stores water, nutrients, and waste products, and plays a role in regulating the cell's internal environment. In contrast, mitochondria, nucleus, and centriole are found in both plant and animal cells.
20.
What is the term for the jelly-like substance that is contained inside the cell membrane?
Correct Answer
A. Cytoplasm
Explanation
The jelly-like substance that is contained inside the cell membrane is called cytoplasm. Cytoplasm is a semi-fluid material that fills the space between the cell membrane and the nucleus. It contains various organelles, such as mitochondria and ribosomes, and is responsible for supporting and protecting the cell's internal structures. Cytoplasm also plays a crucial role in cellular processes, including metabolism and transportation of molecules within the cell.
21.
What is the main function of the Golgi apparatus?
Correct Answer
C. Process and deliver proteins
Explanation
The Golgi apparatus is responsible for processing and delivering proteins within the cell. It receives proteins from the endoplasmic reticulum and modifies them by adding sugars or lipids. It then packages these modified proteins into vesicles and transports them to their final destination within the cell or outside of the cell. Therefore, the main function of the Golgi apparatus is to process and deliver proteins.
22.
Which organelle is the storehouse for most of a cell's genetic information?
Correct Answer
A. Nucleus
Explanation
The nucleus is the storehouse for most of a cell's genetic information. It contains the cell's DNA, which carries the instructions for the cell's functions and characteristics. The DNA is organized into structures called chromosomes, which are located within the nucleus. The nucleus also regulates the cell's activities by controlling the expression of genes and directing the synthesis of proteins. Therefore, the nucleus plays a crucial role in storing and controlling the genetic information of a cell.
23.
Which of the following is a network of proteins that supports and gives shape to a cell?
Correct Answer
A. Cytoskeleton
Explanation
The cytoskeleton is a network of proteins that provides structural support and shape to a cell. It is responsible for maintaining cell shape, facilitating cell movement, and organizing cellular components. It consists of three main types of filaments: microtubules, microfilaments, and intermediate filaments. These filaments work together to give the cell its shape and allow for various cellular processes such as cell division and intracellular transport. The cytoskeleton is essential for maintaining cell integrity and plays a crucial role in cell function and organization.
24.
Which of the following organelles can be found on the surface of the endoplasmic reticulum?
Correct Answer
C. Ribosomes
Explanation
Ribosomes can be found on the surface of the endoplasmic reticulum. This is because the endoplasmic reticulum is responsible for protein synthesis, and ribosomes are the cellular structures where proteins are made. The presence of ribosomes on the surface of the endoplasmic reticulum allows for efficient protein production and transport within the cell.
25.
Unlike a eukaryoteic cell, a prokaryotic cell does not have...
Correct Answer
B. A nucleus.
Explanation
A prokaryotic cell does not have a nucleus. Unlike eukaryotic cells, which have a distinct nucleus that houses the DNA, prokaryotic cells have their genetic material (DNA) floating freely in the cytoplasm. This means that the DNA in prokaryotic cells is not enclosed within a membrane-bound nucleus. Instead, it is found in a region called the nucleoid. Prokaryotic cells are simpler in structure compared to eukaryotic cells, lacking many membrane-bound organelles such as a nucleus.
26.
Which stage of the cell cycle is illustrated on the right?
Correct Answer
B. Cytokinesis
Explanation
The stage of the cell cycle illustrated on the right is cytokinesis. Cytokinesis is the final stage of the cell cycle where the cytoplasm divides and two daughter cells are formed. This process completes the cell division and separates the duplicated chromosomes into two separate cells. The other options - prophase, telophase, and anaphase - are different stages of mitosis, which occur before cytokinesis.
27.
Which of the following is a characteristic of telophase?
Correct Answer
C. Nuclear membrane reforms.
Explanation
During telophase, the final stage of mitosis, the nuclear membrane starts to reform around the separated daughter chromosomes. This process marks the end of nuclear division and the beginning of cytokinesis, where the cytoplasm divides to form two separate daughter cells. The other options mentioned, such as cell growth and normal function, cell growth and preparation for mitosis, and DNA replication, are not characteristics specific to telophase.
28.
The term "mitosis" means ___.
Correct Answer
B. Division of the nucleus.
Explanation
Mitosis is a process of cell division in which the nucleus of a cell divides into two identical nuclei. This process is crucial for growth, development, and repair of tissues in multicellular organisms. The term "mitosis" specifically refers to the division of the nucleus, not the entire cell or other cellular components such as the cytoplasm or DNA replication.
29.
Cell division is very similar in animal and plant cells . However, ___.
Correct Answer
A. Plant cells form a cell plate instead of a cleavage furrow.
Explanation
Plant cells form a cell plate instead of a cleavage furrow during cell division. This is because plant cells have a rigid cell wall that prevents them from pinching inwards to form a furrow. Instead, a new cell wall is formed in the middle of the dividing plant cell, which eventually develops into a cell plate that separates the two daughter cells. This process is known as cytokinesis and is unique to plant cells. Animal cells, on the other hand, form a cleavage furrow by contracting a ring of proteins called actin and myosin, which pinches the cell membrane inward to divide the cell.
30.
Which of the following is a characteristic of anaphase?
Correct Answer
C. Sister chromatids are pulled to opposite sides of the cell.
Explanation
During anaphase, the sister chromatids, which are the replicated copies of each chromosome, are separated and pulled to opposite sides of the cell. This is facilitated by the contraction of the spindle fibers attached to the centromeres of the sister chromatids. This process ensures that each daughter cell receives a complete set of chromosomes. The breakdown of the nuclear membrane occurs in prophase, the alignment of chromosomes in the middle of the cell occurs in metaphase, and the splitting of the cytoplasm occurs in cytokinesis, which follows anaphase.
31.
Which of the following is a characteristic of metaphase?
Correct Answer
B. Chromosomes line up in the middle of the cell.
Explanation
During metaphase, the chromosomes align themselves along the equatorial plane (middle) of the cell. This alignment is crucial for the subsequent separation of sister chromatids during anaphase. The nuclear membrane has already broken down during prophase, and the cytoplasm will split during cytokinesis, which occurs after metaphase. The characteristic that specifically defines metaphase is the alignment of chromosomes in the middle of the cell.
32.
Which of the following is a characteristic of prophase?
Correct Answer
A. Nuclear membrane breaks down.
Explanation
During prophase, the nuclear membrane breaks down. This is an important characteristic of prophase as it allows the chromosomes, which have already replicated during interphase, to be released into the cytoplasm. The breakdown of the nuclear membrane also marks the beginning of the process of mitosis, where the chromosomes will later align in the middle of the cell and sister chromatids will be pulled to opposite sides. However, these events occur in subsequent stages of mitosis and are not specific to prophase.
33.
Which of the following is a characteristic of G2 phase?
Correct Answer
B. Cell growth and preparation for mitosis.
Explanation
G2 phase is the third phase of the cell cycle, following the S phase where DNA is replicated. During G2 phase, the cell continues to grow and prepares for mitosis, the process of cell division. This includes the synthesis of necessary proteins and organelles, as well as the duplication of centrioles. The nuclear membrane reforms during the later stages of G2 phase in preparation for the division of the nucleus during mitosis. Therefore, the characteristic of G2 phase is cell growth and preparation for mitosis.
34.
Some cells live their entire lives without going through mitosis. These cells are said to be in ___.
Correct Answer
A. G zero
Explanation
G zero refers to a phase in the cell cycle where cells temporarily halt their division and enter a non-dividing state. During this phase, cells may undergo differentiation or enter a resting state. It is a crucial stage for cells that do not actively divide or are not ready to divide yet. Therefore, the correct answer is G zero.
35.
Which stage of mitosis is illustrated on the right?
Correct Answer
D. AnapHase
Explanation
The correct answer is anaphase because in anaphase, the sister chromatids separate and move towards opposite poles of the cell. This is clearly depicted in the image on the right, where the chromosomes are seen moving away from each other towards opposite ends of the cell.
36.
Which stage of mitosis is illustrated on the right?
Correct Answer
B. MetapHase
Explanation
The stage of mitosis illustrated on the right is metaphase. In metaphase, the chromosomes align themselves along the equatorial plate of the cell. This alignment ensures that each daughter cell will receive the correct number of chromosomes during cell division. The chromosomes are fully condensed and attached to the spindle fibers at their centromeres. This stage is crucial for the accurate distribution of genetic material to the daughter cells.
37.
Which of the following is a characteristic of S phase?
Correct Answer
D. DNA is replicated.
Explanation
The correct answer is DNA is replicated. During the S phase of the cell cycle, DNA replication takes place. This is a critical process where the DNA molecule is duplicated to ensure that each daughter cell receives a complete set of genetic information. The other options mentioned, such as cell growth and normal function, cell growth and preparation for mitosis, and nuclear membrane reforms, are not specific to the S phase and can occur during other phases of the cell cycle.
38.
All of the following are stages of Interphase except ___.
Correct Answer
D. M
Explanation
The stages of the cell cycle are divided into two main phases: interphase and mitosis. Interphase is the longest phase of the cell cycle and is further divided into three stages: G1, S, and G2. During G1, the cell grows and carries out normal cellular functions. In the S phase, DNA replication occurs. G2 is a period of preparation for cell division. Mitosis, or M phase, is the stage where the cell actually divides into two daughter cells. Therefore, the correct answer is M, as it is not a stage of interphase but rather a stage of mitosis.
39.
In the diagram to the right, the structure labeled E is the ___.
Correct Answer
D. Thylakoid membranes
Explanation
In the given diagram, the structure labeled E appears as a stack of flattened sacs. These sacs are characteristic of thylakoid membranes, which are found within the chloroplasts of plant cells. Thylakoid membranes are responsible for carrying out the light-dependent reactions of photosynthesis, where chlorophyll molecules capture light energy and convert it into chemical energy. Therefore, the correct answer is thylakoid membranes.
40.
In the diagram to the right, the structure labeled D is the ___.
Correct Answer
C. Granum
Explanation
In the diagram to the right, the structure labeled D is the granum. The granum is a stack of thylakoid membranes found in the chloroplasts of plant cells. It is responsible for the light-dependent reactions of photosynthesis, where chlorophyll molecules capture sunlight energy and convert it into chemical energy in the form of ATP and NADPH. The granum plays a crucial role in the production of glucose and oxygen through photosynthesis.
41.
The purpose of the light reactions is to___.
Correct Answer
A. Make ATP and NADpH for use in the Calvin cycle
Explanation
The purpose of the light reactions is to make ATP and NADPH for use in the Calvin cycle. In the light reactions of photosynthesis, light energy is absorbed by chlorophyll and converted into chemical energy in the form of ATP and NADPH. These molecules are then used in the Calvin cycle, which is the second stage of photosynthesis, to produce glucose. Therefore, the primary function of the light reactions is to generate the energy-rich molecules ATP and NADPH, which are essential for the synthesis of glucose.
42.
What are the products of photosynthesis?
Correct Answer
B. Glucose and oxygen
Explanation
Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen. Glucose is a sugar molecule that serves as the primary source of energy for plants. Oxygen is released as a byproduct of this process and is essential for the survival of many organisms, including humans. Therefore, the correct answer is glucose and oxygen.
43.
In the light-independent reactions of photosynthesis,
Correct Answer
A. Carbon dioxide enters the Calvin cycle and sugars are made.
Explanation
In the light-independent reactions of photosynthesis, carbon dioxide enters the Calvin cycle and sugars are made. This is because during the Calvin cycle, carbon dioxide molecules are combined with molecules called RuBP (ribulose bisphosphate) to form an unstable molecule that quickly breaks down into two molecules of PGA (phosphoglycerate). These PGA molecules are then converted into other molecules, eventually leading to the production of glucose and other sugars. This process is essential for the synthesis of organic compounds in plants and is the primary way in which carbon dioxide is fixed into organic molecules during photosynthesis.
44.
Which of the following statements best describes the process of photosynthesis?
Correct Answer
D. Chloroplasts absorb sunlight and store chemical energy.
Explanation
Chloroplasts are organelles found in plant cells that contain chlorophyll, the pigment responsible for absorbing sunlight. During photosynthesis, chloroplasts absorb sunlight and convert it into chemical energy in the form of ATP and NADPH. This energy is then used to convert carbon dioxide and water into glucose and oxygen. Therefore, the statement "Chloroplasts absorb sunlight and store chemical energy" best describes the process of photosynthesis.
45.
What is the term for an organism that makes its own source of chemical energy?
Correct Answer
B. Producer
Explanation
A producer is an organism that is capable of making its own source of chemical energy through the process of photosynthesis or chemosynthesis. This means that it can convert sunlight or inorganic compounds into organic molecules, such as glucose, which can be used as a source of energy. Producers play a crucial role in ecosystems as they provide energy for other organisms through the food chain.
46.
The main light-absorbing molecules found in plant leaves are called
Correct Answer
C. ChloropHyll
Explanation
Chlorophyll is the correct answer because it is the main light-absorbing pigment found in plant leaves. It is responsible for capturing light energy during photosynthesis and converting it into chemical energy. Chlorophyll molecules are located within the chloroplasts, which are the organelles responsible for photosynthesis in plant cells. Thylakoids are membrane structures within the chloroplasts where the chlorophyll molecules are embedded. Grana are stacks of thylakoids. While all of these components are involved in the process of photosynthesis, chlorophyll is specifically the molecule that absorbs light.
47.
The function of the light-dependent reactions is to
Correct Answer
B. Capture and transfer energy.
Explanation
The function of the light-dependent reactions in photosynthesis is to capture and transfer energy. During these reactions, light energy is absorbed by chlorophyll and other pigments in the thylakoid membranes of the chloroplasts. This energy is then used to convert water molecules into oxygen and high-energy molecules such as ATP and NADPH. These energy-rich molecules are later used in the light-independent reactions to build sugars through the process of carbon fixation. Therefore, the light-dependent reactions primarily focus on capturing and transferring energy from sunlight to chemical energy.
48.
Where do the hydrogen ions for the photosystems of the light-dependent reactions come from?
Correct Answer
D. Water
Explanation
In the light-dependent reactions of photosynthesis, the hydrogen ions for the photosystems come from water. During this process, water molecules are split, releasing oxygen, electrons, and protons (hydrogen ions). The electrons are then used to replace the excited electrons in the photosystems, while the hydrogen ions contribute to the formation of a proton gradient that drives ATP synthesis. Ultimately, this splitting of water provides the necessary electrons and hydrogen ions for the photosystems to convert light energy into chemical energy in the form of ATP and NADPH.
49.
Which phrase best describes the electron transport chain in photosynthesis?
Correct Answer
C. A series of proteins located in the thylakoid membrane
Explanation
The electron transport chain in photosynthesis is a series of proteins located in the thylakoid membrane. This chain is responsible for transferring electrons and generating a proton gradient, which is used to produce ATP during the light-dependent reactions of photosynthesis. The thylakoid membrane is where the chlorophyll pigments are located, and it is the site where light energy is captured and converted into chemical energy. The proteins in the electron transport chain play a crucial role in this process by shuttling electrons and facilitating the flow of energy.
50.
The process by which plants use sunlight to make glucose is called ___.
Correct Answer
A. pHotosynthesis
Explanation
Photosynthesis is the correct answer because it is the process through which plants convert sunlight, water, and carbon dioxide into glucose and oxygen. During photosynthesis, plants use the energy from sunlight to fuel the production of glucose, which serves as their main source of energy. This process occurs in the chloroplasts of plant cells, specifically in the chlorophyll pigment. Cellular respiration, on the other hand, is the process through which cells break down glucose to produce energy. The cell cycle and mitosis are unrelated processes involved in cell division and replication.