Chapter 3 the Cellular level

Question 1

What are the three main parts of a eukaryotic cell?

a) plasma membrane, organelles, cytoplasm
b) plasma membrane, organelles, nucleus
c) plasma membrane, cytoplasm, organelles
d) plasma membrane, cytoplasm, nucleus
e) plasma membrane, cytosol, organelles

Answer 1

d) plasma membrane, cytoplasm, nucleus

Question 2

Briefly describe the fluid mosaic model.

Answer 2

The fluid mosaic model states that the molecular arrangement of the plasma membrane resembles an ever-moving sea of fluid lipids containing a mosaic of many different proteins.

Question 3

The three main components of the lipid bilayer portion of a plasma membrane are

a) phospholipids, glycoproteins, and water.
b) proteins, cholesterol, and fatty acids.
c) cholesterol, triglycerides, and glycolipids.
d) phospholipids, cholesterol, and glycolipids.
e) phospholipids, cholesterol, and proteins.

Answer 3

d) phospholipids, cholesterol, and glycolipids.

Question 4

What are the nonpolar parts of phospholipids?

a) phosphate-containing head groups
b) fatty acid tail groups
c) Both the head and tail groups are nonpolar.
d) Neither the head nor tail groups are nonpolar.

Answer 4

b) fatty acid tail groups

Question 5

The polar portion of a cholesterol molecule, which forms hydrogen bonds with the polar heads of neighboring phospholipids and glycolipids, consists of a

a) –OH group.
b) –CH3 group.
c) –CH4 group
d) –COOH group
e) None of these choices is correct.

Answer 5

a) –OH group.

Question 6

This type of membrane protein extends across the entire lipid bilayer of the plasma membrane touching both intracellular fluid and the extracellular fluid.

a) complement protein
b) transmembrane protein
c) peripheral protein
d) lipoprotein
e) All of these choices are correct.

Answer 6

b) transmembrane protein

Question 7

Describe five different functions of integral membrane proteins

Answer 7

Some membrane proteins act as ion channels or carriers that transport substances across the membrane. Other membrane proteins act as receptors that allow the cell to respond to various types of ligands. Other membrane proteins are enzymes that catalyze specific chemical reactions. Still other membrane proteins act as linker proteins that anchor cells to neighboring structures including other cells. Lastly, some membrane proteins serve as cell identity molecules.

Question 8

This type of membrane protein enables cells to catalyze specific chemical reactions at the inner or outer surface of their plasma membrane.

a) receptors
b) phospholipids
c) cholesterol
d) enzymes
e) ligands

Answer 8

l

d) enzymes

Question 9

Which of the following types of membrane proteins function by recognizing and binding to hormones and neurotransmitters?

a) transporters
b) receptors
c) enzymes
d) linkers
e) cell identification markers

Answer 9

b) receptors

Question 10

This type of membrane protein anchors cells to neighboring cells and to protein filaments found outside or inside the cell.

a) transporters
b) receptors
c) ligands
d) ion channels
e) linkers

Answer 10

e) linkers

Question 11

Plasma membranes are _____, which means that some chemicals move easily through plasma membrane while other chemicals do not.

a) selectively permeable
b) concentration graded
c) electrically graded
d) selectively soluble
e) electrical insulators

Answer 11

a) selectively permeable

Question 12

Which of the following does NOT influence the rate of diffusion of a chemical across a plasma membrane?

a) concentration gradient of the chemical across the membrane
b) mass of the diffusing chemical
c) distance that the chemical has to diffuse
d) amount of ATP available
e) temperature

Answer 12

d) amount of ATP available

Question 13

Briefly describe the driving force for the movement of water across plasma membranes.

Answer 13

Water moves across membranes by osmosis, which is driven by solute concentration differences across the membrane. Water moves from the area of low solute concentration to the area of high solute concentrations.

Question 14

This is a measure of a solution’s ability to change the volume of cells by altering their water content.

a) filtration
b) normality
c) tonicity
d) equivalency
e) facilitation

Answer 14

c) tonicity

Question 15

This is the transport process by which gases, like O2 and CO2, move through a membrane.

a) osmosis
b) active transport
c) secondary active transport
d) simple diffusion
e) endocytosis

Answer 15

d) simple diffusion

Question 16

In this type of transport process, a solute (e.g. glucose) binds to a specific carrier protein on one side of the membrane. This binding induces a conformational change in the carrier protein that results in the solute moving down its concentration gradient to the other side of the membrane.

a) osmosis
b) active transport
c) secondary active transport
d) facilitated diffusion
e) endocytosis

Answer 16

d) facilitated diffusion

Question 17

In this transport process, the energy from hydrolysis of ATP is used to drive substances across the membrane against their own concentration gradients.

a) primary active transport
b) secondary active transport
c) facilitated diffusion
d) passive diffusion
e) osmosis

Answer 17

a) primary active transport

Question 18

If the solute concentration is greater inside of the cell than outside the cell, water will move by osmosis

a) into the cell.
b) out of the cell.
c) into and out of the cell at the same rate resulting in no net water movement.
d) All of these answer choices are correct.
e) None of these answers are correct.

Answer 18

a) into the cell.

Question 19

What transport process uses the energy stored in a Na+ or H+ concentration gradient to drive other substances across the membrane against their own concentration gradients?

a) primary active transport
b) secondary active transport
c) facilitated diffusion
d) passive diffusion
e) osmosis

Answer 19

b) secondary active transport

Question 20

Which of the following transport processes uses vesicles that fuse with the plasma membrane to secrete materials into the extracellular fluid?

a) endocytosis
b) exocytosis
c) facilitated diffusion
d) osmosis
e) Both endocytosis and exocytosis.

Answer 20

b) exocytosis

Question 21

Which of the following transport process uses vesicles formed at the plasma membrane to take up extracellular substances and import them into the cell?

a) endocytosis
b) exocytosis
c) facilitated diffusion
d) osmosis
e) Both endocytosis and exocytosis

Answer 21

a) endocytosis

Question 22

List the steps involved in receptor-mediated endocytosis.

Answer 22

The steps involved in receptor-mediated endocytosis include 1)ligand binding, 2)vesicle formation, 3)uncoating of the vesicle, 4)fusion of the vesicle with endosome, 5)recycling of receptors to the plasma membrane, and 6)degradation of the ligand in the lysosome.

Question 23

During phagocytosis, binding of a particle to a plasma membrane receptor triggers formation of _____, which are extensions of the plasma membrane of the phagocyte that eventually surround the particle forming a phagosome.

a) podocytes
b) exterior vesicles
c) interior vesicles
d) pseudopods
e) lysosomes

Answer 23

d) pseudopods

Question 24

Which of the following is NOT a characteristic of the cytosol?

a) primarily consists of water
b) cation of electron transport chain carrier proteins
c) site of many important chemical reactions
d) often contains aggregates of triglycerides that form lipid droplets
e) contains the enzymes of glycolysis

Answer 24

d) often contains aggregates of triglycerides that form lipid droplets

Question 25

Specialized structures within a cell that have a characteristic shape and perform specific functions in cellular growth, maintenance and reproduction are called

a) organelles.
b) cytoskeletons.
c) cytoplasm.
d) cytosol.
e) nuclei.

Answer 25

a) organelles.

Question 26

Microfilaments, intermediate filaments and microtubules are all components of a cell’s

a) cytoskeleton.
b) nucleus.
c) plasma membrane.
d) flagella.
e) ribosome.

Answer 26

a) cytoskeleton.

Question 27

This cellular organelle is comprised of a pair of centrioles and the surrounding pericentriolar material.

a) cytoskeleton
b) cilia
c) centrosome
d) flagella
e) peroxisomes

Answer 27

c) centrosome

Question 28

Spermatozoa is the only type of human cell that contains a _____, which is a whip-like structure that helps propel the sperm towards an oocyte.

a) cilium
b) flagellum
c) mitochondria
d) centrosome
e) microvillus

Answer 28

b) flagellum

Question 29

Which of the following membrane-enclosed organelles is the site of synthesis of membrane proteins and secretory proteins?

a) rough endoplasmic reticulum
b) smooth endoplasmic reticulum
c) nucleus
d) centrosome
e) Golgi complex

Answer 29

a) rough endoplasmic reticulum

Question 30

Which of the following membrane-enclosed organelles modifies, sorts, and packages proteins destined for other regions of the cell?

a) endoplasmic reticulum
b) Golgi complex
c) peroxisomes
d) nucleus
e) proteasome

Answer 30

b) Golgi complex

Question 31

Briefly state the functions of the rough and smooth endoplasmic reticulum.

Answer 31

The rough endoplasmic reticulum synthesizes glycoproteins, phospholipids and digestive enzymes that are transferred to other cellular organelles, inserted into the plasma membrane, secreted during exocytosis or stored in the lysosomes.
The smooth endoplasmic reticulum synthesizes fatty acids and steroids, detoxifies harmful substances, removes phosphate groups from glucose-6-phosphate, and stores and releases calcium ions that trigger contractions in muscle fibers.

Question 32

Briefly describe how proteins move through the Golgi complex

Answer 32

Proteins are packaged into transport vesicles by the rough endoplasmic reticulum membrane. These vesicles enter on the (cis) face of the Golgi complex, and the proteins move through the cisternae, from (cis) face through to exit (trans) face. Proteins will leave from the (trans) face of the Golgi complex in vesicles that will deliver the protein to plasma membrane, secretory vesicles, or to other organelles in the cell.

Question 33

Which of the following membrane-enclosed organelles contains several oxidases that are involved in oxidation of fatty acids and amino acids during normal metabolism and in detoxification of chemicals like alcohol in the liver?

a) peroxisomes
b) mitochondria
c) proteasome
d) ribosomes
e) lysosomes

Answer 33

a) peroxisomes

Question 34

Which of the following membrane-enclosed organelles can engulf a worn-out organelle, digest its chemical components, and recycle those digested components?

a) peroxisomes
b) mitochondria
c) proteasome
d) ribosomes
e) lysosomes

Answer 34

e) lysosomes

Question 35

The major function of mitochondria is to

a) move the cell.
b) generate ATP.
c) produce proteins.
d) oxidize organelles.
e) synthesize glycolipids.

Answer 35

b) generate ATP.

Question 36

Which of the following protects the contents of the nucleus?

a) nucleic acids
b) nuclear membrane
c) centrosome
d) cilia
e) Golgi complex

Answer 36

b) nuclear membrane

Question 37

What is the major function of histones?

a) needed for helix formation of the DNA
b) add negative charge to the DNA
c) help organize coiling and folding of the DNA
d) degrade faulty proteins in the nucleus
e) catalyze methylation of the DNA

Answer 37

c) help organize coiling and folding of the DNA

Question 38

Briefly explain the difference between transcription and translation.

Answer 38

Transcription is making mRNA from DNA and it occurs in the nucleus, while translation is making a protein from the information in mRNA and happens in the cytosol of the cell.

Question 39

This portion of a DNA segment does not code for a protein.

a) RNA
b) introns
c) exons
d) polyribosome
e) ribosome

Answer 39

b) introns

Question 40

Briefly describe alternative splicing.

Answer 40

Alternative splicing of mRNA is a process in which the pre-mRNA transcribed from a gene is spliced in different ways to produce several different mRNAs. The different mRNAs are used to make different proteins.

Question 41

Define homologous chromosomes

Answer 41

Homologous chromosomes contain similar genes arranged in the same (or almost the same) order.

Question 42

During this phase of cell division, organelles duplicate and centrosome replication begins.

a) interphase
b) prophase
c) metaphase
d) anaphase
e) telophase

Answer 42

a) interphase

Question 43

During this phase of cell division, the centromeres split leading to separation and subsequent migration of the two members of a chromatid pair to opposite poles of the cells. The cleavage furrow also begins to develop during this phase.

a) interphase
b) prophase
c) metaphase
d) anaphase
e) telophase

Answer 43

d) anaphase

Question 44

In the diagram, which organelle is responsible for autophagy and autolysis?

a) C
b) B
c) F
d) J
e) D

Answer 44

a) C

Question 45

In the diagram, which organelle is used to modify, sort and transport proteins?

a) D
b) I
c) A
d) J
e) G

Answer 45

d) J

Question 46

In the diagram, which organelle aids movement of the cell?

a) A
b) G
c) H
d) D
e) I

Answer 46

a) A

Question 47

In the diagram, this structure directs cellular activities.

a) D
b) F
c) G
d) A
e) H

Answer 47

c) G

Question 48

In the diagram, which one represents carrier-mediated facilitated diffusion?

a) A
b) B
c) C
d) Both A and C
e) Both B and C

Answer 48

c) C

Question 49

In the diagram, which one represents a hypertonic solution

a) A
b) B
c) C
d) Both B and C
e) All of these choices are correct.

Answer 49

c) C

Question 50

Describe briefly what is occurring at each step in the figure.

Answer 50

This figure represents protein synthesis. Step one, the initiator tRNA attaches to a start codon. In step two, the large and small ribosomal subunits join to form a functional ribosome and initiator tRNA fits into P site. In step three, the anticodon of an incoming tRNA pairs with the next mRNA codon at A site. Step four, the amino acid on the tRNA at P site forms a peptide bond with the amino acid at A site. Step five, the tRNA at the P site leaves the ribosome and the ribosome shifts down by one codon. The tRNA previously at the A site is now at the P site. Step six is when protein synthesis stops when the ribosome reaches one of three potential stop codons on the mRNA strand.

Question 51

In the diagram, which panel shows events occurring during anaphase?

a) A
b) B
c) C
d) D
e) E

Answer 51

d) D

Question 52

In the diagram, which panel shows the kinetochore of the centromeres aligning along the center of the mitotic spindle of the cell?

a) A
b) B
c) C
d) D
e) E

Answer 52

c) C

Question 53

In the diagram, which panel shows cells that are in interphase?
1 A
2 C
3 F

a) 1 only
b) 2 only
c) 3 only
d) 1 and 3
e) 1, 2, and 3

Answer 53

d) 1 and 3

Question 54

Compare and contrast primary and secondary active transport.

Answer 54

Both are energy requiring transport processes that are capable of moving substances against their concentration gradients. Energy obtained from hydrolysis of ATP drives primary active transport, while energy stored in an ionic concentration gradient drives secondary active transport.

Question 55

Compare mitosis to meiosis

Answer 55

Mitosis is somatic cell division that produces two identical cells with the same number (diploid) and kinds of chromosomes as the original cell. Meiosis is reproductive cell division that produces cells in which the number of chromosomes in the nucleus is reduced in half (haploid)

Question 56

What structural component of the membrane is labeled (E) in the diagram?

a) glycoprotein
b) cholesterol
c) channel protein
d) glycolipid
e) phospholipid

Answer 56

b) cholesterol

Question 57

What structural components of the membrane are labeled (C) in the diagram?

a) peripheral proteins
b) cholesterol molecules
c) pores
d) integral proteins
e) phospholipids

Answer 57

d) integral proteins

Question 58

What structural component of the membrane is labeled (B) in the diagram?

a) glycoprotein
b) cholesterol
c) glycolipid
d) channel protein
e) phospholipid

Answer 58

a) glycoprotein

Question 59

Which of the following represents an ion channel?

a) F
b) C
c) D
d) A
e) E

Answer 59

d) A

Question 60

Which of the following shows ligand binding at the cell surface?

a) B
b) C
c) D
d) A
e) E

Answer 60

b) C

Question 61

Most intravenous solutions are _____ with respect to blood cells?

a) tonicity
b) isotonic
c) hypertonic
d) osmotic
e) hypotonic

Answer 61

b) isotonic

Question 62

Which of the following is the correct sequence of events in receptor-mediated endocytosis shown in the figure?

a) binding > degradation in lysosomes > vesicle formation > uncoating > recycling of receptors to plasma membrane > fusion with endosome
b) degradation in lysosomes > fusion with endosome > recycling of receptors to plasma membrane > uncoating > vesicle formation > binding
c) degradation in lysosomes > recycling of receptors to plasma membrane > fusion with endosome > uncoating > vesicle formation > binding
d) binding > vesicle formation > uncoating > fusion with endosome > recycling of receptors to plasma membrane > degradation in lysosomes
e) binding > uncoating > vesicle formation > fusion with endosome > degradation in lysosomes > recycling of receptors to plasma membrane

Answer 62

d) binding > vesicle formation > uncoating > fusion with endosome > recycling of receptors to plasma membrane > degradation in lysosomes

Question 63

Which of the following is the correct sequence of events in phagocytosis shown in the figure?

a) pseudopods surround particle > phagosome formed > fusion of lysosome and phagosome > digestion by lysosomal enzymes > residual body formed
b) phagosome formed > pseudopods surround particle > fusion of lysosome and phagosome > digestion by lysosomal enzymes > residual body formed
c) phagosome formed > pseudopods surround particle > fusion of lysosome and phagosome > residual body formed > digestion by lysosomal enzymes
d) residual body formed > phagosome formed > pseudopods surround particle > fusion of lysosome and phagosome > digestion by lysosomal enzymes
e) fusion of lysosome and phagosome > residual body formed > phagosome formed > pseudopods surround particle > digestion by lysosomal enzymes

Answer 63

a) pseudopods surround particle > phagosome formed > fusion of lysosome and phagosome > digestion by lysosomal enzymes > residual body formed

Question 64

Which of the following is the correct sequence of events in bulk-phase endocytosis shown in the figure?

a) plasma membrane forms vesicle around extracellular droplets > fusion of lysosome and vesicle > vesicle formed pinches off into cytosol > digestion by enzymes > solutes released
b) solutes released > plasma membrane forms vesicle around extracellular droplets > fusion of lysosome and vesicle > vesicle formed pinches off into cytosol > digestion by enzymes
c) vesicle formed pinches off into cytosol > solutes released > plasma membrane forms vesicle around extracellular droplets > fusion of lysosome and vesicle > digestion by enzymes
d) vesicle formed pinches off into cytosol > plasma membrane forms vesicle around extracellular droplets > fusion of lysosome and vesicle > digestion by enzymes > solutes released
e) plasma membrane forms vesicle around extracellular droplets > vesicle formed pinches off into cytosol > fusion of lysosome and vesicle > digestion by enzymes > solutes released

Answer 64

e) plasma membrane forms vesicle around extracellular droplets > vesicle formed pinches off into cytosol > fusion of lysosome and vesicle > digestion by enzymes > solutes released

Question 65

Which of the following transport processes moves substances through cells using endocytosis on one side of a cell and exocytosis on the opposite side of the cell?

a) phagocytosis
b) secondary active transport
c) transcytosis
d) osmosis
e) simple diffusion

Answer 65

c) transcytosis

Question 66

Which disease below is an inherited condition characterized by the absence of a single lysosomal enzyme called Hex A?

a) Tay-Sachs disease
b) leukemia
c) progeria
d) lymphoma
e) Werner syndrome

Answer 66

a) Tay-Sachs disease

Question 67

Which organelle is responsible for synthesis of steroids, phospholipids and functions as a reservoir for Ca2+?

a) mitochondrion
b) secretory vesicle
c) smooth endoplasmic reticulum
d) rough endoplasmic reticulum
e) lysosome

Answer 67

c) smooth endoplasmic reticulum

Question 68

What other organelle besides the nucleus contain DNA?

a) Golgi complex
b) lysosome
c) ribosomes
d) mitochondrion
e) centrosome

Answer 68

d) mitochondrion

Question 69

This is the site of synthesis of rRNA and assembly of rRNA and proteins into ribosomal subunits.

a) nucleus
b) nucleolus
c) smooth endoplasmic reticulum
d) rough endoplasmic reticulum
e) Golgi complex

Answer 69

b) nucleolus

Question 70

What compound would a cell lacking ribosomes be unable to make?

a) lipids
b) nucleotides
c) proteins
d) carbohydrates
e) phospholipids

Answer 70

c) proteins

Question 71

The following is a particular sequence of base triplet on a DNA molecule: ATG. What is the corresponding codon for the mRNA?

a) TAC
b) GUA
c) GTA
d) CTA
e) UAC

Answer 71

e) UAC

Question 72

The following is a particular sequence of codon on mRNA: ACU. What is the corresponding anti-codon for the tRNA?

a) UGA
b) UCA
c) TGA
d) TCA
e) AUC

Answer 72

a) UGA

Question 73

Describe the difference between the cytoplasm and the cytosol.

Answer 73

The cytoplasm is all the cellular material (organelles and fluid) between the plasma membrane and the nucleus, while the cytosol is only the fluid portion of the cytoplasm.

Question 74

The difference in concentration of a specific chemical, like Na+, on the inside and outside of a plasma is referred as a(n)

a) electrochemical potential.
b) membrane potential.
c) electrical gradient.
d) concentration gradient.
e) biological capacitance

Answer 74

d) concentration gradient.

Question 75

An orderly, genetically programmed cell death is referred to as ________, while disorganized pathological cell death is referred to as ________.

a) apoptosis; synapsis
b) apoptosis; necrosis
c) necrosis; apoptosis
d) synapsis; necrosis
e) necrosis; synapsis

Answer 75

b) apoptosis; necrosis

Question 76

Which of the cells in the diagram contains structural adaptations that increase surface area for absorption?
1 B 
2 C 
3 D 
4 E

a) 3 and 4
b) 1 only
c) 2 only
d) 3 only
e) 4 only

Answer 76

a) 3 and 4