Ch03 HW: The Cell
Mr. Weddington was admitted to the hospital with chronic heart failure. His feet and legs were swollen with fluid. He should be given a hypotonic drip to draw fluid out of his cells. True False
False
Sister chromatids of a chromosome are joined at a region called the centrosome. True False
False
To make a protein, DNA first is replicated into RNA, and then RNA is transcribed into amino acids. True False
False
Which organelle modifies, sorts, and packages proteins and lipids for export from the cell? mitochondrion Golgi apparatus endoplasmic reticulum cytoskeleton
Golgi apparatus
The stage of mitosis during which sister chromatids separate and daughter chromosomes are pulled to opposite poles of the cell is called __________. metaphase telophase prophase anaphase
anaphase
Programmed cell death is called: metastasis. neoplasia. apoptosis. hydrolysis.
apoptosis.
You can differentiate the smooth endoplasmic reticulum (SER) from the rough endoplasmic reticulum (RER) due to the presence of ________ on the RER. free ribosomes bound lysosomes bound ribosomes bound peroxisomes
bound ribosomes
What is NOT a function of the plasma membrane? catalyze macromolecules into subunits isolate the cell from its surroundings communication with other cells structural support
catalyze macromolecules into subunits
A cell is placed into a 3% dextrose solution. At that concentration, the solution is isotonic to the cell. If the concentration of dextrose in the solution is increased to 5%, the cell is now in a(n): hypotonic solution. less concentrated solution. hypertonic solution. isotonic solution.
hypertonic solution.
If the ECF is more concentrated than the cytosol, then the ECF is: monotonic. hypotonic. isotonic. hypertonic.
hypertonic.
Cellular swelling is likely to occur when blood cells are immersed in: hypertonic solutions. hypotonic solutions. more concentrated solutions. isotonic solutions.
hypotonic solutions.
The tRNA molecule binds a start codon of the mRNA molecule during: transcription. initiation. termination. elongation.
initiation.
The stage of the cell cycle in which the cell grows and prepares for cell division is called: metaphase. interphase. mitosis. cytokinesis.
interphase.
Cytosol is also known as: blood plasma. intracellular fluid (ICF). extracellular fluid (ECF). the cytoskeleton.
intracellular fluid (ICF).
Resting membrane potential is due to unequal concentrations of: acids and bases. phospholipids and proteins. water molecules. ions.
ions.
What are the two steps of protein synthesis that produce a protein from a gene? transcription and translation replication and transcription mitosis and cytokinesis replication and translation
transcription and translation
The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____. primary active transport secondary active transport simple diffusion exocytosis facilitated diffusion
primary active transport
If a chemotherapy drug prevents the mitotic spindle from forming during the M phase of the cell cycle, then what specific phase has been disrupted? metaphase anaphase prophase telophase
prophase
What is the correct order of the phases in the M phase of the cell cycle? prophase, anaphase, metaphase, telophase metaphase, prophase, anaphase, telophase prophase, metaphase, anaphase, telophase anaphase, telophase, prophase, metaphase
prophase, metaphase, anaphase, telophase
What is NOT a function of the peroxisome? synthesize certain phospholipids oxidize toxic substances break down fatty acids protein synthesis
protein synthesis
Active transport processes: move solutes with or along their concentration gradients. move solutes through the phospholipid bilayer without the use of integral proteins. move solutes from a higher concentration to a lower concentration. require cells to expend energy (ATP).
require cells to expend energy (ATP).
Where does protein synthesis occur? lysosomes peroxisomes mitochondria ribosomes
ribosomes
Carbon dioxide is a small molecule that moves through the phospholipid bilayer with its concentration gradient by: simple diffusion. osmosis. primary active transport. facilitated diffusion.
simple diffusion.
Which of the following is least likely to increase the rate of diffusion? small molecule size small concentration gradient higher concentration of molecules high temperature
small concentration gradient
Which of the following is NOT a function of the plasma membrane proteins? stabilizing temperature acting as enzymes acting as channels acting as carriers
stabilizing temperature
If the ECF is hypotonic, the cell will: divide. swell. shrink. remain unchanged.
swell.
The completion of cytokinesis accompanies: prophase. anaphase. metaphase. telophase.
telophase.
During osmosis, water moves across a selectively permeable membrane toward a solution with: the lowest solute concentration. more water molecules. the lowest osmotic pressure. the highest solute concentration.
the highest solute concentration.
If a cell has 18 chromosomes and undergoes mitosis, how many chromosomes would each daughter cell have? 36 18 72 9
18
Place the following steps of endomembrane system function in the correct order. 1. Golgi apparatus receives transport vesicles from the RER. 2. Ribosomes on the RER synthesize proteins. 3. Proteins are packaged into transport vesicles. 4. Modified proteins may be secreted from the cell by exocytosis. 5. Proteins are modified by the Golgi apparatus. 2, 4, 3, 1, 5 3, 2, 1, 4, 5 1, 2, 3, 5, 4 2, 3, 1, 5, 4
2, 3, 1, 5, 4
How many homologous chromosome pairs are present in most human cells? 4 23 46 18
23
Place the following steps of protein synthesis in the correct order as they occur. 1. mRNA is produced in the nucleus. 2. Ribosome moves along mRNA. 3. DNA uncoils for transcription. 4. Polypeptide is produced. 5. tRNA brings amino acids to the ribosome. 6. mRNA moves to the ribosome. 2, 1, 5, 4, 3, 6 3, 5, 1, 6, 2, 4 2, 4, 6, 1, 3, 5 3, 1, 6, 2, 5, 4
3, 1, 6, 2, 5, 4
Part A Part complete How many codons are present in the following strand of mRNA? U A C G G U A G U A U G 12 4 6 3
4
Transcribe mRNA from this strand of DNA. T A C G G T A G T U T G C C U T G U A T G C C A T C A U A G C C U A C U A U G C C A U C A
A U G C C A U C A
Elongation of the polypeptide continues as long as a new tRNA molecule situates in the: M site of the ribosome. P site of the ribosome. E site of the ribosome. A site of the ribosome.
A site of the ribosome.
Provide the tRNA anticodon that is complementary to this mRNA codon: UAC. TUG ATG AUG TAG
AUG
During osmosis, the solvent moves across a selectively permeable membrane from a solution with a higher solute concentration to a solution with a lower solute concentration. True False
False
Why is cholesterol a critical component of the plasma membrane? Cholesterol serves a role in cell recognition. Cholesterol transports certain molecules into the cell. Cholesterol catalyzes metabolic reactions from its position within the plasma membrane. Cholesterol stabilizes the structure of the plasma membrane when the temperature changes.
Cholesterol stabilizes the structure of the plasma membrane when the temperature changes.
During which phase of mitosis are sister chromatids separated when the mitotic spindle fibers shorten? metaphase telophase anaphase prophase
anaphase
What is the role of DNA helicase during the S phase of interphase? DNA helicase removes the RNA primer and replaces it with DNA. DNA helicase catalyzes the addition of nucleotides to the new DNA strands. DNA helicase builds RNA primers on the existing DNA strands. DNA helicase unwinds the two strands of DNA.
DNA helicase unwinds the two strands of DNA.
Which of the following is not a major difference between DNA and RNA? DNA is found in the nucleus and cytoplasm, but RNA is only found in the nucleus DNA uses deoxyribose and RNA uses ribose as their respective pentose sugars DNA is a double-stranded helix and RNA is a single-stranded helix DNA contains thymine, but RNA contains uracil instead
DNA is found in the nucleus and cytoplasm, but RNA is only found in the nucleus
What occurs during the period of interphase known as the S phase? The cell is rapidly synthesizing proteins. DNA replication (synthesis) takes place. Proteins, organelles, and cytosol are divided between the daughter cells. Genetic material is divided between the daughter cells.
DNA replication (synthesis) takes place.
Cells may lyse when placed into a hypertonic environment. True False
False
What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane? In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient. Simple diffusion requires molecules to move through special doorways in the cell membrane. Simple diffusion is passive but facilitated diffusion is an active process that uses energy. In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
Cell division occurs during: M phase. G1 phase. G2 phase. S phase.
M phase.
Which of the following is most likely to move through the cell membrane by facilitated diffusion? CO2 O2 Na+ small lipids
Na+
What is the role of RNA polymerase in transcription? RNA polymerase signals the end of the mRNA molecule. RNA polymerase carries the code for the amino acid in a sequence of nucleotides. RNA polymerase catalyzes the unwinding of the DNA double helix. RNA polymerase binds the DNA promoter and builds an mRNA molecule.
RNA polymerase binds the DNA promoter and builds an mRNA molecule.
Which of the following best describes secondary active transport? Secondary active transport involves the movement of a substance into a cell with its concentration gradient. Secondary active transport occurs when one substance is coupled with the passive transport of a second substance. Secondary active transport involves the movement of water by osmosis into a cell. Secondary active transport involves the movement of a substance into a cell through a protein channel with its concentration gradient.
Secondary active transport occurs when one substance is coupled with the passive transport of a second substance.
Which of the following statements about the cytoskeleton is FALSE? The cytoskeleton provides the characteristic shape and size to a cell. The cytoskeleton synthesizes proteins. The cytoskeleton functions in movement. The cytoskeleton supports the plasma and nuclear membranes.
The cytoskeleton synthesizes proteins.
Which of the following describes the fluid mosaic model of the plasma membrane structure? The phospholipid bilayer is embedded with associated proteins, cholesterol and sugars and has a dynamic arrangement. Phospholipids consist of a polar head and a nonpolar tail made of three fatty acid chains. The lipid bilayer is solid at body temperature, thus protecting the cell. The plasma membrane is composed of two layers of proteins embedded with lipids.
The phospholipid bilayer is embedded with associated proteins, cholesterol and sugars and has a dynamic arrangement.
The Na+/K+ pump transports three sodium ions out of the cell for every two potassium ions moved into the cell. This is an example of: a symport pump. an antiport pump. a uniport pump. facilitated diffusion.
an antiport pump.
Which of the following best describes the structure of the plasma membrane? The plasma membrane is a single-layered membrane that surrounds the nucleus of the cell. The plasma membrane is a phospholipid bilayer surrounding the cell. The plasma membrane is composed of cristae. The plasma membrane is a double layer of protein enclosing the plasma.
The plasma membrane is a phospholipid bilayer surrounding the cell.
Both cilia and flagella are constructed of a ring of nine pairs of microtubules surrounding two central microtubules. True False
True
Cytokinesis occurs concurrently with telophase of the M phase of the cell cycle. True False
True
Nuclear pores connect the cytoplasm with the nucleoplasm and allow substances to move between the two areas. True False
True
The fluid mosaic model defines the plasma membrane as a structure composed of multiple components, including the phospholipid bilayer, proteins, carbohydrates, and other lipids that exist in a dynamic arrangement. True False
True
You determine a cell to lack both centrioles and mitotic spindle fibers and conclude it will not be able to complete mitosis. True False
True
Simple diffusion requires: protein channels. carrier proteins. the use of energy. a concentration gradient.
a concentration gradient.
The total solute concentration of a red blood cell is about 2%. Sucrose cannot pass through a red blood cell's plasma membrane, but water and urea can. Which of the following solutions will cause a red blood cell to shrink? a hypertonic urea solution a hypertonic sucrose solution a hypotonic urea solution a hypotonic sucrose solution
a hypertonic sucrose solution
A process that requires energy to move a substance against its concentration gradient is called: active transport. osmosis. passive transport. facilitated transport.
active transport.
Which of the following components of the nucleus is composed of DNA? nuclear envelope chromatin nuclear lamina nuclear pores
chromatin
Tightly coiled DNA molecules present during cell division are known as: chromosomes. the nucleoplasm. the nuclear envelope. the nucleosome.
chromosomes.
Which of the following best describes a cell's response to being placed into an extracellular solution that is hypertonic to the cytosol? crenation swelling no net gain or loss of water lysis
crenation
What process divides the cytosol, organelles, and proteins? mitosis synthesis cytokinesis prophase
cytokinesis
Which of the following would NOT be a component of the plasma membrane? cytoskeleton phospholipids glycoproteins cholesterol
cytoskeleton
Human cells that lack centrioles cannot: metabolize sugars. divide. move. synthesize proteins.
divide
A substance moves by facilitated diffusion into a cell. What is required for its transport? either a protein channel or a carrier protein both ATP and a protein channel a pump ATP only
either a protein channel or a carrier protein
Which of the following processes are functionally opposite to one another? simple diffusion and facilitated diffusion endocytosis and exocytosis phagocytosis and pinocytosis osmosis and simple diffusion
endocytosis and exocytosis
Two types of active transport via vesicles are: endocytosis and exocytosis. simple diffusion and facilitated diffusion. diffusion and osmosis. primary active transport and secondary active transport.
endocytosis and exocytosis.
A white blood cell engulfs a bacterium through a process called: endocytosis. facilitated diffusion. exocytosis. primary active transport.
endocytosis.
A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____. active transport facilitated diffusion endocytosis exocytosis simple diffusion
exocytosis
What is NOT one of the three main parts of a cell? extracellular fluid plasma membrane cytoplasm nucleus
extracellular fluid
Sodium ions are moving with their concentration gradient with the use of a protein channel across a plasma membrane. Determine the type of membrane transport used to transport these sodium ions. primary active transport osmosis facilitated diffusion simple diffusion
facilitated diffusion
Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____. facilitated diffusion exocytosis active transport simple diffusion endocytosis
facilitated diffusion
The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____. simple diffusion active transport facilitated diffusion a process that requires energy from the cell cotransport
facilitated diffusion
Through the microscope, you see cells swimming. Each cell has a long tail that moves in a whip-like manner. What type of cellular extension have you observed? cilium centriole microvillus flagellum
flagellum
The triplet codes in DNA needed to specify a specific polypeptide chain are found in the: cytoplasm. anticodon of tRNA. codon of mRNA. gene.
gene.
Solution A and solution B are separated by a semipermeable membrane. Solution A contains 1% glucose, solution B contains 5% glucose. By diffusion: water will move from solution B to solution A. water will move from solution A to solution B. glucose will move from solution B to solution A. glucose will move from solution A to solution B.
glucose will move from solution B to solution A.
What organelle degrades old, worn-out organelles and cell components? peroxisome rough endoplasmic reticulum (RER) lysosome Golgi apparatus
lysosome
Cancer cells: are indistinguishable from normal body cells. have a slower mitotic rate than normal body cells. do not spread into other body tissues. may exhibit metastasis.
may exhibit metastasis.
Muscle cells require an abundant amount of ATP to function. Therefore, muscle cells have numerous: lysosomes. peroxisomes. mitochondria. ribosomes.
mitochondria.
Before the mRNA transcribed from a gene can be used for translation into a protein, it must be: modified to remove exons, introns spliced together, and transported to a tRNA molecule. coated with phospholipids for transport out of the nucleus. folded into its proper three-dimensional configuration. modified to remove introns, exons spliced together, and transported into the cytosol.
modified to remove introns, exons spliced together, and transported into the cytosol.
A primary active transport process is one in which __________. molecules pass directly through the phospholipid bilayer of the plasma membrane molecules move across the plasma membrane without an input of energy the plasma membrane folds inward to form a vesicle containing extracellular material molecules move through transport proteins that have been activated by ATP an intracellular vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid
molecules move through transport proteins that have been activated by ATP
Which of the following best explains diffusion? movement of molecules from an area of high concentration to an area of low concentration movement of molecules from where there are fewer of them to where there are more exchange of nonpolar molecules for polar molecules movement of molecules farther away from equilibrium
movement of molecules from an area of high concentration to an area of low concentration
Cells that stall in a state of the cell cycle known as G0 are said to be: dead cells. cancerous cells. nondividing cells. rapidly dividing cells.
nondividing cells.
Within the nucleus, where does ribosome assembly occur? nuclear pore centromere nucleolus nucleoplasm
nucleolus
Most of a cell's DNA is located in its: nucleus. lysosomes. ribosomes. Golgi apparatus.
nucleus
Where does transcription of DNA into RNA occur? nucleus Golgi apparatus peroxisome mitochondrion
nucleus
Molecular machines that perform specific functions for the cell are: the plasma membrane. cytosol. the cytoskeleton. organelles.
organelles.
Aquaporins may be employed during: endocytosis. osmosis. simple diffusion. active transport.
osmosis.
The reactions of oxidative catabolism, or aerobic respiration, can occur in the mitochondrion only in the presence of: alkaline pH. hydrogen ions. oxygen. carbon dioxide.
oxygen.
What is NOT part of the endomembrane system? endoplasmic reticulum lysosome peroxisome Golgi apparatus
peroxisome
Tetracycline is an antibiotic used to treat infections. It binds with bacterial ribosomes and inhibits the tRNA molecule from binding to the ribosome. What process is interrupted? transcription replication mitosis translation
translation
The unit of DNA that specifies a certain amino acid is called a ________, the same unit of mRNA is called a(n) ________ which, during protein synthesis, is matched by the ________ of tRNA. triplet; codon; anticodon nucleotide; triplet; gene gene; triplet; amino acid triplet; anticodon; codon
triplet; codon; anticodon
Microtubules are composed of protein subunits known as: tubulin. myosin. actin. keratin.
tubulin.
The main component of the cytosol is: sugars. water. the nucleus. organelles.
water
What is transported across a membrane during osmosis? water solutes salts sugars
water
Solution A and solution B are separated by a semipermeable membrane. Solution A contains 1% glucose, solution B contains 5% glucose. By osmosis: glucose will move from solution A to solution B. glucose will move from solution B to solution A. water will move from solution A to solution B. water will move from solution B to solution A.
water will move from solution A to solution B.
