Cell Biology - Biology
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Which of the following organelles is found in plant cells, but not in animal cells?
Which of the following organelles is found in plant cells, but not in animal cells?
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Plant cells are very similar to animal cells, but receive energy from sunlight. As a result, they require chloroplasts in order to house the chlorophyll where photosynthesis takes place. Animal cells are incapable of photosynthesis, and do not contain chloroplasts.
The other listed structures are found in both animal and plant cells.
Plant cells are very similar to animal cells, but receive energy from sunlight. As a result, they require chloroplasts in order to house the chlorophyll where photosynthesis takes place. Animal cells are incapable of photosynthesis, and do not contain chloroplasts.
The other listed structures are found in both animal and plant cells.
The nucleolus .
The nucleolus .
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The nucleolus is a subdivision of the nucleus; thus, it is only found in eukaryotes. It is the site of ribosome assembly. The nucleolus is made of RNA and proteins.
The nucleolus is a subdivision of the nucleus; thus, it is only found in eukaryotes. It is the site of ribosome assembly. The nucleolus is made of RNA and proteins.
In the chemical reaction of photosynthesis, photoautotrophs combine carbon dioxide and water to produce sugar and which of the following?
In the chemical reaction of photosynthesis, photoautotrophs combine carbon dioxide and water to produce sugar and which of the following?
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Sugar (glucose) and oxygen are the two products of photosynthesis. Methane is a gas consisting of carbon and hydrogen. ATP is the energy produced in the organelle mitochondria. Ethyl alcohol is the active substance in beer and wine that causes intoxication if too much is consumed.
Sugar (glucose) and oxygen are the two products of photosynthesis. Methane is a gas consisting of carbon and hydrogen. ATP is the energy produced in the organelle mitochondria. Ethyl alcohol is the active substance in beer and wine that causes intoxication if too much is consumed.
Prior to the onset of menstruation, the development of primary oocytes is paused in what phase of meiosis?
Prior to the onset of menstruation, the development of primary oocytes is paused in what phase of meiosis?
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Primary oocytes enter meiosis I and replicate their genomes, but they do not make their first meiotic division. They remain in prophase I until a female begins her first menstrual cycle. Then, each month, one primary oocyte resumes the process of meiotic division.
Primary oocytes enter meiosis I and replicate their genomes, but they do not make their first meiotic division. They remain in prophase I until a female begins her first menstrual cycle. Then, each month, one primary oocyte resumes the process of meiotic division.
Where does fertilization of the ovum typically occur?
Where does fertilization of the ovum typically occur?
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Fertilization typically occurs in the fallopian tube. After fertilization, the diploid zygote will begin the process of implantation into the uterus, where it undergoes mitotic divisions. The resulting multicellular organism is called the embryo, which further develops in the uterus into a fetus.
Fertilization typically occurs in the fallopian tube. After fertilization, the diploid zygote will begin the process of implantation into the uterus, where it undergoes mitotic divisions. The resulting multicellular organism is called the embryo, which further develops in the uterus into a fetus.
Most cells spend the vast majority of their time in .
Most cells spend the vast majority of their time in .
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Most cells spend about 90% of their time in interphase. Note that mitosis and meiosis comprise only about 10% of the cell cycle.
Most cells spend about 90% of their time in interphase. Note that mitosis and meiosis comprise only about 10% of the cell cycle.
Out of all phases in the cell cycle, most cells spend the majority of their life in .
Out of all phases in the cell cycle, most cells spend the majority of their life in .
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Cell division, or mitosis, is a rather small portion of a cell's life and includes prophase, metaphase, anaphase and telophase. The majority of a cell's life is spent in interphase.
Cell division, or mitosis, is a rather small portion of a cell's life and includes prophase, metaphase, anaphase and telophase. The majority of a cell's life is spent in interphase.
DNA replication occurs during which of the following phases of the cell cycle?
DNA replication occurs during which of the following phases of the cell cycle?
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DNA is synthesized in the S phase only. The G phases are stages of cellular growth while the M phase consists of mitotic cellular division.
DNA is synthesized in the S phase only. The G phases are stages of cellular growth while the M phase consists of mitotic cellular division.
How is mitochondrial DNA (mDNA) different from nuclear DNA?
How is mitochondrial DNA (mDNA) different from nuclear DNA?
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Mitochondrial DNA is much smaller and simpler than nuclear DNA, meaning it does not need histones or introns. Mitochondrial DNA is also circular, like bacterial DNA, rather than linear like nuclear DNA. As the ovum is the only contributor of mitochondria to an offspring, all mDNA must therefore be inherited from the mother.
Mitochondrial DNA is much smaller and simpler than nuclear DNA, meaning it does not need histones or introns. Mitochondrial DNA is also circular, like bacterial DNA, rather than linear like nuclear DNA. As the ovum is the only contributor of mitochondria to an offspring, all mDNA must therefore be inherited from the mother.
What is the "powerhouse" of the cell?
What is the "powerhouse" of the cell?
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The mitochondria is responsible for making the energy for the cell by cellular respiration. It does this by taking the major breakdown products of glucose (pyruvate and NADH) and converting them into ATP by the citric acid cycle and electron transport chain. This is an oxygen-dependent process.
The mitochondria is responsible for making the energy for the cell by cellular respiration. It does this by taking the major breakdown products of glucose (pyruvate and NADH) and converting them into ATP by the citric acid cycle and electron transport chain. This is an oxygen-dependent process.
Which of the following organelles has only one membrane?
Which of the following organelles has only one membrane?
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Lysosomes are specialized vesicles that bud off of the Golgi apparatus and house digestive enzymes within the cell. Lysosomes have only one outer membrane, made of a phospholipid bilayer, similar to the plasma membrane surrounding the cell.
In contrast, the nucleus, mitochondria, and chloroplasts all have two outer membranes. Each of these is made of a lipid bilayer, for a total of four layers of phospholipids around these structures.
Lysosomes are specialized vesicles that bud off of the Golgi apparatus and house digestive enzymes within the cell. Lysosomes have only one outer membrane, made of a phospholipid bilayer, similar to the plasma membrane surrounding the cell.
In contrast, the nucleus, mitochondria, and chloroplasts all have two outer membranes. Each of these is made of a lipid bilayer, for a total of four layers of phospholipids around these structures.
Which structures are responsible for breaking down proteins, nucleic acids, lipids, and carbohydrates?
Which structures are responsible for breaking down proteins, nucleic acids, lipids, and carbohydrates?
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Lysosomes are membrane-bound organelles that contain digestive enzymes which break down all four types of macromolecules. The mitochondria is responsible for synthesis of the majority of the cell's energy in the form of ATP. The cytoskeleton maintains cell shape and provides a "freeway" for transporting substances within the cell. Flagella are proteinaceous structures that aid in cell motility.
Lysosomes are membrane-bound organelles that contain digestive enzymes which break down all four types of macromolecules. The mitochondria is responsible for synthesis of the majority of the cell's energy in the form of ATP. The cytoskeleton maintains cell shape and provides a "freeway" for transporting substances within the cell. Flagella are proteinaceous structures that aid in cell motility.
What is responsible for the movement of proteins, RNA, and other specific molecules into and out of the nucleus?
What is responsible for the movement of proteins, RNA, and other specific molecules into and out of the nucleus?
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Nuclear pores are complex structures made up of proteins which allow movement of certain molecules into and out of the nucleus. Flagella are long tail-like projections found on some cells that function in cell motility. The rough endoplasmic reticulum has ribosomes on it, which are the sites of protein synthesis. Lysosomes are organelles that contain hydrolytic enzymes used to recycle/destroy macromolecules.
Nuclear pores are complex structures made up of proteins which allow movement of certain molecules into and out of the nucleus. Flagella are long tail-like projections found on some cells that function in cell motility. The rough endoplasmic reticulum has ribosomes on it, which are the sites of protein synthesis. Lysosomes are organelles that contain hydrolytic enzymes used to recycle/destroy macromolecules.
What is the main difference between DNA in prokaryotes and eukaryotes?
What is the main difference between DNA in prokaryotes and eukaryotes?
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Prokaryotes have a single circular DNA molecule, and eukaryotes have multiple linear chromosomes. The four nucleotides for DNA are in both prokaryotes and eukaryotes.
Prokaryotes have a single circular DNA molecule, and eukaryotes have multiple linear chromosomes. The four nucleotides for DNA are in both prokaryotes and eukaryotes.
Which of the following is a function of ribosomes?
Which of the following is a function of ribosomes?
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Ribosomes are composed of ribosomal RNA (rRNA) and proteins. Their primary function is to bind mRNA and tRNA to build proteins. Ribosomes are the fundamental structure necessary for translation and protein formation.
The nucleus houses the DNA of the cell, the cytoskeleton and specialized proteins transport compounds within the cell, and the smooth endoplasmic reticulum breaks down toxic substances, such as alcohol.
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. Their primary function is to bind mRNA and tRNA to build proteins. Ribosomes are the fundamental structure necessary for translation and protein formation.
The nucleus houses the DNA of the cell, the cytoskeleton and specialized proteins transport compounds within the cell, and the smooth endoplasmic reticulum breaks down toxic substances, such as alcohol.
Which of the following does not contain a cell wall?
Which of the following does not contain a cell wall?
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A cell wall is a tough, and rigid layer of polysaccharides lying outside of the plasma membrane in plants, some fungi, and some protists. The cell wall provides these cells with structural support and protection. It also prevents over-expansion when water enters the cell. Animal cells lack a cell wall, and only have a plasma membrane.
A cell wall is a tough, and rigid layer of polysaccharides lying outside of the plasma membrane in plants, some fungi, and some protists. The cell wall provides these cells with structural support and protection. It also prevents over-expansion when water enters the cell. Animal cells lack a cell wall, and only have a plasma membrane.
What is the best description of the fluid-mosaic model for a cell's membrane?
What is the best description of the fluid-mosaic model for a cell's membrane?
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The fluid-mosaic model for the cell membrane is a double layer of phospholipids with embedded proteins. The proteins do active transport in pumping molecules across the membrane. The phosphates are on the outside and the lipid chains are on the inside of the membrane.
The fluid-mosaic model for the cell membrane is a double layer of phospholipids with embedded proteins. The proteins do active transport in pumping molecules across the membrane. The phosphates are on the outside and the lipid chains are on the inside of the membrane.
Which of the following are true of cell walls?
Which of the following are true of cell walls?
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The cell wall provides support and protection for the cell. Most are made from carbohydrate and protein. They are not made of phospholipids or lipids.
The cell wall provides support and protection for the cell. Most are made from carbohydrate and protein. They are not made of phospholipids or lipids.
What kind of membrane makes up the nuclear envelope?
What kind of membrane makes up the nuclear envelope?
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A double phospholipid bilayer membrane makes up the nuclear envelope. The outer layer of this nuclear envelope is continuous with the endoplasmic reticulum, also known as cytoplasm's interior membrane system. The cell's plasma membrane, and the membranes surrounding various organelles (except the nucleus, and mitochondria which both have double phospholipid bilayers) are single phospholipid bilayers. Cell walls are found outside the plasma membrane of plant, bacterial, and fungal cells. Peptidoglycan is the main component of the cell walls of bacteria.
A double phospholipid bilayer membrane makes up the nuclear envelope. The outer layer of this nuclear envelope is continuous with the endoplasmic reticulum, also known as cytoplasm's interior membrane system. The cell's plasma membrane, and the membranes surrounding various organelles (except the nucleus, and mitochondria which both have double phospholipid bilayers) are single phospholipid bilayers. Cell walls are found outside the plasma membrane of plant, bacterial, and fungal cells. Peptidoglycan is the main component of the cell walls of bacteria.
Where does the Krebs cycle take place in the mitochondria?
Where does the Krebs cycle take place in the mitochondria?
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The mitochondria are the site for aerobic respiration in the cell. Both the Krebs cycle and electron transport chain are found in the mitochondria, while glycolysis (anaerobic metabolism) takes place in the cytoplasm. The Krebs cycle takes place in the mitochondrial matrix, where pyruvate is used to generate NADH and FADH2. These molecules are then taken to the inner mitochondrial membrane, where the electron transport chain is located. The electron transport chain pushes protons into the intermembrane space, creating the proton gradient that fuels ATP synthesis.
The mitochondria are the site for aerobic respiration in the cell. Both the Krebs cycle and electron transport chain are found in the mitochondria, while glycolysis (anaerobic metabolism) takes place in the cytoplasm. The Krebs cycle takes place in the mitochondrial matrix, where pyruvate is used to generate NADH and FADH2. These molecules are then taken to the inner mitochondrial membrane, where the electron transport chain is located. The electron transport chain pushes protons into the intermembrane space, creating the proton gradient that fuels ATP synthesis.