Deck 3: Cells As Units of Life

Question 1

Major functions of the plasma membrane do NOT include

A) regulating molecules and ions that pass into and out of the cell.
B) recognizing and communicating between different cells and tissues.
C) maintaining connections between adjacent cells.
D) producing proteins used in construction of the cell.

Answer 1

D

Question 2

A high-powered microscope that produces a surface image from scattered secondary electrons is the

A) brightfield light microscope.
B) transmission electron microscope (TEM).
C) scanning electron microscope (SEM).
D) confocal microscope.

Answer 2

C

Question 3

Which of the following is a correct statement comparing prokaryotic and eukaryotic cells?

A) Both must provide for transfer of genetic information
B) Both must have some individuals that reproduce
C) Both must separate their interior world from the external world
D) All of the choices are correct

Answer 3

D

Question 4

In a phospholipid bilayer,the

A) Cholesterol is on the outside and plays a critical role in maintaining the fluidity of the membrane
B) Glycoproteins are on the inside providing a supporting site for adhesive functions
C) Glycoproteins are anchored in the plasma membrane to assist in their transport functions
D) Water-soluble ends are oriented toward the exterior and interior of the cell, whereas the fat-soluble fatty acids are oriented toward the inside of the membrane

Question 5

Biologists label various carbohydrates,fats and amino acids with radio-isotopes,place them in a cell culture,and allow time for cell metabolism.Then by disrupting cells in a blender and separating out various cell organelles,they find the radioactive molecules can be detected as part of various cellular compounds although visible cell structures appear unchanged.Therefore

A) these "food" molecules are used only for energy.
B) most cell components are constantly being broken down and rebuilt.
C) molecules diffuse at random through the cytoplasm and into cell organelles.
D) radioactivity has an unusual role in metabolism of living cells.

Question 6

Which is NOT a characteristic of mitochondria?

A) A mitochondrion has two membranes
B) Mitochondria are the site of cellular respiration
C) Mitochondria contain their own genome
D) Mitochondria are replicated by nuclear chromosomes

Question 7

The Dutch microscopist who sent letters to the Royal Society of London describing his many detailed observations of life,including units later known to be cells,was

A) Anton van Leeuwenhoek.
B) Robert Hooke.
C) Matthais Schleiden.
D) J. Purkinje.

Question 8

When water in a cell freezes slowly,sharp crystals spear through the membranes of the cell.The most likely explanation for the bad taste of meat that has "freezer burn" from repeated freeze/thaw cycles is the destruction of

A) the Golgi bodies and their vesicles.
B) lysosomes and resultant autodigestion.
C) rough endoplasmic reticulum causing the release of ribosomes.
D) the nuclear membrane causing mixing of nucleoplasm and cytoplasm.

Question 9

Movement is not only a feature of animal cells but of all eukaryotic cells.Which of the following are involved in a cell's ability to move?

A) Microtubules
B) Microfilaments
C) Actin and myosin
D) All of the choices are correct

Question 10

Which element is NOT correctly associated with its structures and function?

A) Cilia have 9 pair of microtubules surrounding a central pair
B) Microtubules are made up of a protein called tubulin
C) Pseudopodia stream without the involvement of any microfilaments
D) Centrioles have a microtubule structure

Question 11

The best definition of diffusion is

A) movement of molecules from higher concentration to lower concentration.
B) movement of water across a semi-permeable membrane from high water concentration to lower water concentration.
C) movement of molecules from lower concentration to higher concentration.
D) movement of a substance against its concentration through the release of energy from ATP.

Question 12

Which of the following is NOT true about the Cell Theory?

A) It states that all organisms are composed of cells
B) It states that all cells come from preexisting cells
C) It states that small organisms can arise spontaneously
D) It is accepted today by biologists as applying to virtually all forms of life

Question 13

An important technique that allows biologists to trace the fate of chemicals in metabolic pathways is the use

A) of the immunofluorescence microscope.
B) of radioactive isotopes.
C) of time lapse photography.
D) of centrifugation.

Question 14

Which is true concerning the Golgi complex?

A) It consists of a stack of membranous vesicles
B) Golgi complexes in animal cells have a forming face and a maturing face
C) Lysosomes are enzyme-filled vesicles that bud from the Golgi complex
D) All of the choices are correct

Question 15

The current theory of the structure of the plasma membrane is best described by which of the following models.

A) The fluid-mosaic model
B) The unit membrane model
C) The electrochemical model
D) The nuclear envelope model

Question 16

Which correctly describes ribosomes?

A) Ribosomes contain both DNA and protein
B) Ribosomes are active in carbohydrate synthesis
C) Ribosomal subunits leave the nucleolus and form ribosomes in the cytoplasm
D) Ribosomes are found associated with the endoplasmic reticulum in prokaryotic cells

Question 17

Technically,osmosis is

A) movement of molecules from higher concentration to lower concentration.
B) movement of water across a semi-permeable membrane from high water concentration to lower water concentration.
C) movement of molecules from lower concentration to higher concentration.
D) movement of water across a semi-permeable membrane from low water concentration to higher water concentration.
E) movement of a substance against its concentration through the release of energy from ATP.

Question 18

Which of the following is a correct statement concerning the comparison of prokaryotic and eukaryotic cells?

A) Mitosis is common to both groups
B) Flagella and cilia of both groups are identical with a "9 + 2" microtubular pattern
C) The DNA nucleoid of a prokaryote is not membrane bound; the nucleus of a eukaryote is membrane bound
D) All of the choices are correct

Question 19

Which is the best definition of active transport?

A) Movement of molecules from higher concentration to lower concentration
B) Movement of water across a semi-permeable membrane from high water concentration to lower water concentration
C) Movement of molecules from lower concentration to higher concentration
D) Movement of a substance against its concentration through the release of energy from ATP

Question 20

The surface of some parasitic flatworms and some insect tissues is a "syncytium" or living layer that contains many nuclei and cell organelles but is not partitioned by plasma membranes.These tissues consume food,respire,and produce wastes.Since the cell theory states that "all living things are composed of cells" what is the best statement to accompany this question?

A) These tissues are not living because they are not cellular
B) These tissues are obviously a bridge between nonliving and primitive living cells
C) The general concept of "life is cellular" still holds because these organisms still utilize cells sometime in their life, but this shows that plasma membrane partitions can be abandoned in some animals
D) This proves that a "vital force" beyond cell chemistry gives life to substances

Question 21

Cell products such as undigested residues are removed from the cell through

A) facilitated transport.
B) cotransport.
C) endocytosis.
D) exocytosis.

Question 22

Which does NOT occur in telophase?

A) Cytokinesis is underway
B) Nuclear envelope is reconstructed
C) Centromeres split apart
D) Chromosomes decondense into chromatin

Question 23

Phospholipids in a plasma membrane are oriented such that the water-soluble or _________ ends face outside and the fat-soluble or hydrophobic ends face inward.

Question 24

In most animal cells,the majority of the cell cycle is spent in

A) metaphase.
B) anaphase.
C) interphase.
D) prophase.

Question 25

The two stages of cell division are

A) initiation and completion.
B) duplication of chromosomes and division of chromosomes.
C) mitosis and cytokinesis.
D) None of the choices are correct.

Question 26

At the completion of mitosis,

A) each chromosome is composed of a single chromatid once more.
B) the daughter cell nuclei have acquired the same number and kinds of chromosomes as the parent cell nucleus.
C) the cell may not have yet undergone cytokinesis.
D) All of the above are correct.

Question 27

The model of the plasma membrane that provides for the fluidity of materials embedded in its surface is the

Question 28

The sodium-potassium pump moves sodium and potassium ions across the plasma membrane by

A) facilitated transport.
B) active transport.
C) cotransport.
D) endocytosis.

Question 29

The specific form of endocytosis wherein small areas of the surface membrane are invaginated to form tiny vesicles containing fluids.

A) Pinocytosis
B) Cotransport
C) Endocytosis
D) Exocytosis

Question 30

Which occurs during anaphase?

A) Centrioles move to opposite poles
B) Chromosomes line up along the equator of the dividing cell
C) Chromatids move to opposite poles
D) The nuclear envelope disappears

Question 31

Which occurs during metaphase?

A) Centrioles move to opposite poles
B) Chromosomes line up along the equator of the dividing cell
C) Chromosomes move to opposite poles
D) The nuclear envelope disappears

Question 32

Which sequence of stages in mitosis is correct?

A) Prophase, anaphase, metaphase, telophase
B) Prophase, telophase, anaphase, metaphase
C) Prophase, metaphase, anaphase, telophase
D) Anaphase, metaphase, prophase, telophase

Question 33

Sugars and amino acids move into the cell by the sodium-potassium pump by means of

A) facilitated transport.
B) active transport.
C) simple diffusion.
D) endocytosis.

Question 34

Apoptosis or programmed cell death is receiving much research attention because

A) it is a normal part of embryonic development.
B) it is the cause of most animal diseases.
C) all "death" is bad and this is one of the few remaining causes of natural death to be overcome.
D) it is always caused by a fault in the cell cycle at G₁ phase, G₂ phase or S phase.

Question 35

A paramecium is placed in a hypotonic solution.Which will occur?

A) Salts will move into the paramecium from the surrounding solution
B) Water will move into the paramecium from the surrounding solution
C) Salts will move out of the paramecium into the surrounding solution
D) Water will move out of the paramecium into the surrounding solution

Question 36

Which represents the correct sequence of stages in the cell cycle?

A) S, G₁, G₂
B) G₂, S, G₁
C) G₁, S, G₂
D) G₁, G₂, S

Question 37

If a fish is placed in an isotonic solution,which will occur?

A) Salts will move into the fish from the surrounding solution
B) Water will move into the fish from the surrounding solution
C) Salts will move out of the fish into the surrounding solution
D) Water will move out of the fish into the surrounding solution
E) None of the choices will occur

Question 38

Dermal stem cells divide,with some cells continuing the stem cell line and others being pushed toward the surface to flatten and die and be sloughed off.In the bone marrow,other stem cells produce cells such as the red blood cells that lose their nucleus and function for a short time before they too die.These cells that reproduce no further

A) leave the cell cycle in a G₀ phase, which immediately follows telophase.
B) leave the cell cycle in a G₃ phase, which immediately follows G_2.
C) halt in the midst of the S phase.
D) continually cycle but simply fail to go through cytokinesis.

Question 39

Cyclin-dependent kinases and cyclins are most closely associated with

A) maintaining interphase.
B) regulating the cell cycle.
C) cytokinesis.
D) programmed cell death.

Question 40

If the nucleus divides many times without cytokinesis occurring,the result is

A) cell death.
B) interphase.
C) a multinucleate cell.
D) an incomplete spindle.

Question 41

During the tug-of-war during metaphase,condensed sister chromatids move to the middle of the cell and line up along a __________ ___________.

Question 42

Pinocytosis involves invaginated units called ________ that contain concentrations of specific binding receptors on their surface.

Question 43

If there is life on other planets,would it necessarily resemble life that has evolved on Earth? Why or why not?

Question 44

Describe the structure of cilia and flagella in eukaryotic cells,and contrast that with the structure of flagella in prokaryotic cells.

Question 45

Cancer occurs in somatic (or body)cells.Explain how the process of mitosis might be railroaded into producing cancerous cells.

Question 46

Identify the various cell structures that have an endomembrane system; identify the function of each.What is unusual about eukaryotic organelles that have an endomembrane system?

Question 47

Describe the structure and function of a ribosome,and describe how they differ between prokaryotes and eukaryotes.

Question 48

Compare and contrast the various stages of mitosis and meiosis.Hypothesize which process arose first (explain your reasoning).

Question 49

How is the cell theory related to the principle of evolution? Describe how principles of the cell theory are important to understand evolution.

Question 50

A multinucleate mass formed by the fusion of many cells rather than by nuclear proliferation is called a ____________.

Question 51

Distinguish between a nucleus and a nucleoid,identifying where each is found and what each contains,and why it is important to distinguish between the two.