Deck 4: Functioning Cells

Question 1

The main difference between prokaryotic cells and eukaryotic cells is

A) prokaryotic cells have more internal, membrane-bound compartments than eukaryotic cells.
B) eukaryotic cells have membrane-bound subcellular compartments, called organelles, and prokaryotic cells do not.
C) prokaryotic cells have linear DNA and eukaryotic cells have circular DNA.
D) prokaryotic cells have a nucleus and eukaryotic cells do not.
E) eukaryotic cells contain double-stranded DNA while prokaryotic cells do not.

Answer 1

eukaryotic cells have membrane-bound subcellular compartments, called organelles, and prokaryotic cells do not.

Question 2

Dinoflagellates (protists) and Salmonella (bacteria) are tiny, flagellated organisms. One is a prokaryote and one a eukaryote so we know they must differ in the following ways.

A) The Dinoflagellate must be multicellular with membrane-bound organelles while the Salmonella must be unicellular and lacking membrane-bound organelles.
B) The Dinoflagellate must have flagella made up of microtubules and have membrane-bound organelles while the Salmonella must have flagella made of flagellin and lack membrane-bound organelles.
C) The Dinoflagellate must be multicellular with linear DNA while the Salmonella must be unicellular with circular DNA.
D) The Dinoflagellate must have flagella made up of microtubules and circular DNA while the Salmonella must have flagella made up of flagellin and linear DNA.
E) The Dinoflagellate must be multicellular with flagella made up of microtubules while the Salmonella must be unicellular and have flagella made of flagellin.

Answer 2

The Dinoflagellate must have flagella made up of microtubules and have membrane-bound organelles while the Salmonella must have flagella made of flagellin and lack membrane-bound organelles.

Question 3

A primary function of plasma membranes is to

A) allow only water and non-polar molecules to pass into and out of cells and organelles.
B) allow the passage of water into and out of cells but prevent movement of other molecules.
C) regulate the flow of molecules into and out of cells and organelles.
D) provide an impermeable protective barrier, sealing cells and organelles from their surrounding environment.
E) provide a protective barrier but allow specific ions to pass in and out of the cell.

Answer 3

regulate the flow of molecules into and out of cells and organelles.

Question 4

Which of the following are all functions performed by membrane proteins?

A) Transport facilitation, enzyme activity, provision of a relatively impermeable bilayer structure
B) Enzyme activity, chemical reception, regulation of membrane fluidity
C) Transport facilitation, enzyme activity, chemical reception
D) Transport facilitation, regulation of membrane fluidity, chemical reception
E) Chemical reception, provision of a relatively impermeable bilayer structure, regulation of membrane fluidity

Question 5

Phospholipids make effective biological membranes because they

A) are hydrophobic and repel water.
B) are amphipathic polar and can aggregate into a bilayer.
C) interact with proteins to stabilise the bilayer.
D) contain a hydrophilic phosphate group.
E) can form strong covalent bonds between each other.

Question 6

The surface area of a plasma membrane increases

A) during exocytosis but not during endocytosis.
B) only if a severe osmotic imbalance occurs causing excess water to rush into the cell.
C) during both endocytosis and exocytosis as incoming and outgoing vesicles fuse with the plasma membrane.
D) during endocytosis but not during exocytosis.
E) when forming clathrin-coated pits.

Question 7

A major function of the nucleolus is to

A) control the movement of substances into and out of the nucleus.
B) manufacture and store DNA.
C) make ribosomal RNA components.
D) replicate DNA molecules.
E) import proteins into the nucleus for RNA synthesis.

Question 8

If you viewed the following through a light microscope, in which would you expect to see the largest, darkest nucleolus?

A) An animal cell that was actively producing large amounts of protein
B) A red blood cell
C) An animal cell that was involved in little protein production
D) An animal cell at metaphase of mitosis
E) A plant cell during cell division

Question 9

Which of the following is INCORRECT about chromosomes?

A) They consist of chromatin strands.
B) They are important in cell division.
C) They make up DNA.
D) Parts of them, termed euchromatin, are areas of active gene transcription.
E) They can be visible through a light microscope.

Question 10

Which of the following statements about the nuclear envelope is true?

A) Nuclear pores are rigid with a fixed diameter.
B) The outer membrane is continuous with the endoplasmic reticulum.
C) The outer membrane is highly permeable, allowing ions and small molecules to pass freely.
D) The inner membrane is continuous with the endoplasmic reticulum.
E) The inner and outer membranes have similar chemical composition.

Question 11

The nuclear lamina is

A) a structural framework of proteins on the inner surface of the nuclear membrane.
B) the innermost of the two nuclear membranes.
C) proteins lining the cytoplasmic side of the nucleus to anchor the nuclear pores.
D) the very thin, dark staining membrane that surrounds the nucleolus.
E) the meshwork of proteins that give shape to the nuclear pores.

Question 12

Ribosomes are

A) composed of two subunits.
B) joined with mRNA to make proteins.
C) often associated with rough endoplasmic reticulum.
D) assembled in the nucleolus.
E) All of the answers are correct.

Question 13

In eukaryotes, polypeptide synthesis occurs in

A) the nucleolus, where synthesis of ribosomal RNA occurs.
B) the cytosol, either free or in association with the outside surface of the rough endoplasmic reticulum.
C) the lumen of the endoplasmic reticulum, either free or in association with the inside surface of the rough endoplasmic reticulum.
D) association with the outside surface of the smooth endoplasmic reticulum.
E) the mitochondria cytosol in association with the Golgi cis-membrane.

Question 14

In a cell that specialises in producing a steroid hormone you would expect to find

A) a greater than average quantity of rough endoplasmic reticulum.
B) a greater than average quantity of smooth endoplasmic reticulum.
C) a greater than average number of mitochondria to provide energy for synthesis.
D) much less endoplasmic reticulum than in an average cell.
E) no structural differences from an average cell.

Question 15

The Golgi apparatus

A) is found only in prokaryotes.
B) is the main site of lipid production for membranes.
C) is a network of tubular membranes.
D) processes and packages many different substances for transport to other sites in the cell.
E) is the site of degradation of unwanted cellular proteins.

Question 16

Choose the sequence that best describes the progress of an enzyme from synthesis to its final destination in a lysosome.

A) Rough endoplasmic reticulum, cis face of Golgi apparatus, trans face of Golgi apparatus, endolysosome, vesicle.
B) Smooth endoplasmic reticulum, cis face of Golgi apparatus, cis face of Golgi apparatus, vesicle, endolysosome.
C) Rough endoplasmic reticulum, cis face of Golgi apparatus, trans face of Golgi apparatus, vesicle, endolysosome.
D) Rough endoplasmic reticulum, trans face of Golgi apparatus, cis face of Golgi apparatus, vesicle, endolysosome.
E) Smooth endoplasmic reticulum, cis face of Golgi apparatus, trans face of Golgi apparatus, vesicle, endolysosome.

Question 17

In which cells of an organism would you expect to find the highest numbers of mitochondria?

A) Those involved in structural support.
B) Those most metabolically active.
C) Those producing proteins for secretion.
D) Those providing protective outer layers.
E) All cells in a given organism have the same number of mitochondria.

Question 18

The double mitochondrial membrane allows the generation of potential energy because the

A) composition and chemical structure of the inner and outer membranes are very similar.
B) inner membrane is highly permeable to most substances allowing ions to flow into the matrix.
C) inner membrane is highly impermeable not allowing passage of ions and molecules.
D) outer membrane is highly impermeable not allowing passage of ions and molecules.
E) outer membrane is highly impermeable allowing H⁺ ions to accumulate on the inner surface of the inner mitochondrial membrane.

Question 19

Chlorophyll molecules are found

A) associated with the thylakoid membrane of chloroplasts.
B) in the stroma of chloroplasts only.
C) evenly distributed in the chloroplast.
D) in amyloplasts and chromoplasts.
E) associated with the permeable outer membrane of chloroplasts.

Question 20

Chloroplasts and Mitochondria have the following in common

A) an inner and outer membrane; their own circular DNA; a membrane system that enables them to produce ATP from trapped light energy.
B) an inner and outer membrane, a stroma, their own circular DNA.
C) an inner and outer membrane, a membrane system that enables them to produce ATP, small ribosomes.
D) a permeable outer membrane and an impermeable inner membrane that allows them to produce ATP.
E) an inner and outer membrane, their own circular DNA, a membrane system that enables them to produce ATP using energy released by glucose metabolism.

Question 21

Plastids

A) are found in prokaryotes and eukaryotes.
B) are thought to have developed from bacteria.
C) are surrounded by a single membrane.
D) do not contain any DNA.
E) have an impermeable double membrane.

Question 22

A hypothetical genetic mutation, which resulted in malfunctioning microbodies, is discovered in mice. You would expect affected mice to show symptoms of

A) collapse of soft tissue, due to lack of structural support within the cells.
B) cumulative physical deterioration, due to the inability of cells to form an effective mitotic spindle.
C) infertility, due to an inability of cells to form an effective meiotic spindle and also B above.
D) toxicity, due to an accumulation of cellular byproducts.
E) enlarged liver due to the increased production of glyoxysomes to replace the malfunctioning microbodies.

Question 23

Which of the following is incorrect about both lysosomes and microbodies?

A) They lack DNA.
B) They remove compounds generated within the cell.
C) They contain hydrolytic enzymes.
D) They are surrounded by a single membrane.
E) They lack ribosomes.

Question 24

In eukaryotes, microtubules are

A) strong, stable and resistant to stretching.
B) less rigid than microfilaments and can provide less mechanical support.
C) involved in chromosome separation during cell division.
D) found only in cilia and flagella.
E) composed of actin and provide the cytoskeleton of the cell.

Question 25

Which of the following is INCORRECT?

A) Microfilaments cause cytoplasmic streaming in large plant cells.
B) Microtubules support specialised extensions from the cell.
C) The cytoskeleton ensures that organelles only ever stay in the one place.
D) Cytoskeleton consists of both microtubules, microfilaments and intermediate filaments.
E) Microtubules are hollow cylinders composed of tubulin.

Question 26

Which of the following is surrounded by a double membrane?

A) Smooth endoplasmic reticulum
B) The nucleus
C) A lysosome
D) Golgi apparatus
E) Microbodies

Question 27

Which of the following structures would you expect to find only in animal cells?

A) Chloroplasts.
B) Mitochondria.
C) Nuclei.
D) Lysosomes.
E) Ribosomes.

Question 28

You will NOT find DNA in

A) mitochondria.
B) chloroplasts.
C) the cytosol.
D) plastids.
E) DNA is found in all these organelles.

Question 29

All cells

A) contain organelles where biological reactions occur.
B) contain a nucleus.
C) are bound by a double membrane.
D) have permeable membranes.
E) contain plastids.

Question 30

In eukaryotes, intermediate filaments are

A) strong, stable and resistant to stretching.
B) less rigid than microfilaments and provide less mechanical support than microtubules.
C) composed of actin and provide the cytoskeleton of the cell.
D) involved in chromosome during cell division.
E) found only in cilia and flagella.

Question 31

Nuclear lamins are

A) microtubules that are involved in cell division.
B) intermediate filaments that are cross-linked forming a lattice to support the nuclear membrane.
C) microtubules that radiate out from the nucleus to the plasma membrane.
D) rigid groups of microtubules often cross-bridged by microtubule-associated proteins.
E) highly dynamic structures composed of G-actin and the actin-binding protein profilin.

Question 32

Cytoplasmic organisation and motility are a result of the

A) interaction of the actin-binding protein gelsolin with actin to polymerise the filaments.
B) activity of microtubule-binding proteins (MAPs) and ATPases.
C) interaction between organelles and elements of the cytoskeleton.
D) interaction of the tubulin with myosin.
E) rigidity of the microfilaments which provide mechanical support for the organelles.

Question 33

Peripheral membrane proteins

A) interact with the hydrophobic regions of the membrane through covalent bonding.
B) are usually denatured when removed from membranes.
C) are generally non-covalently bound to membrane lipids.
D) may have functional parts on both sides of the membrane.
E) can only be released from membranes by treatment with detergents.

Question 34

Which of the following statements about the nucleus of a cell is INCORRECT?

A) Proteins imported into the nucleus require a nuclear localisation signal that interacts with the DNA.
B) The nucleolus is a region in the nucleus where ribosomes are synthesised.
C) The nucleus contains DNA and is surrounded by the membrane envelope which is perforated by nuclear pores.
D) Nuclear pores regulate the passage of proteins and RNA in and out of the nucleus.
E) In the nucleus, long DNA molecules wind around clusters of histone proteins which allow the DNA to form chromosomes.

Question 35

The endoplasmic reticulum is

A) continuous with the outer membrane of the nuclear envelope.
B) the site for protein synthesis for cellular proteins.
C) able to form direct connections between adjacent plant cells.
D) a network of membranes that extends through eukaryotic cells.
E) the site of lipid synthesis.

Question 36

Lysosomes

A) are the main organelle for removal of compounds generated within the cell.
B) are membrane-bound organelles involved in the breakdown of material brought into the cell by endocytosis.
C) lack DNA and ribosomes.
D) contain hydrolytic enzymes that are active at pH 5.0.
E) are surrounded by a single membrane.

Question 37

In cells, the cytoplasm consists of

A) ribosomes and cytosol.
B) cytosol and organelles with the exception of the nucleus.
C) all fluidic material within the cellular membrane.
D) just cytosol.
E) all material within the cellular membrane.

Question 38

Why is a bacterial flagella described as a 'motor-complex'?

A) Because it is the primary heat source for the cell
B) Because it spins and propels the cell forward
C) Because it converts fuel into chemical energy
D) Because it continuously pumps protons across the cell membrane
E) All of these options are incorrect

Question 39

Why is staining and fluorescence commonly used in advanced microscopy?

A) Because most cells and cellular components are transparent
B) To highlight particular regions of a cell
C) To demonstrate a relationship between one or more molecules in situ
D) To identify the expression pattern of one or more genes
E) All of these options are correct

Question 40

In a cell membrane, why must the hydrophobic and hydrophilic molecules of the phospholipid bilayer arrange in a strict orientation?

A) Hydrophobic tails face outwards to prevent too much water entering the cell, which would otherwise result in the cell lysing.
B) Hydrophilic heads face inwards so that water is drawn in to the cell to maintain H₂O levels.
C) Hydrophilic tails face inwards and hydrophobic heads face outwards to maintain the structural and functional integrity of the membrane, thus controlling the movement of solutes.
D) Hydrophilic heads face inwards and hydrophobic tails face outwards to maintain the structural and functional integrity of the membrane, thus controlling the movement of solutes.
E) Hydrophobic tails face inwards and hydrophilic heads face outwards to maintain the structural and functional integrity of the membrane, thus controlling the movement of solutes.

Question 41

Which of the following is NOT commonly found in association with the cell membrane?

A) Glycolipids
B) Integral proteins
C) Peripheral proteins
D) Cytochrome
E) Cholesterol

Question 42

In general, how much of cellular membrane mass is comprised of proteins?

A) 20%
B) 30%
C) 60%
D) 40%
E) 50%

Question 43

Two models currently exist as to the mechanism behind how glycoproteins and polysaccharides are processed and packaged in the Golgi apparatus. Which of the following statements is true in relation to at least one of these models?

A) Cargo molecules, having entered the cis-most cisterna, then progress through consecutive cisterna. In each cisterna the molecules are processed by enzymes specific to that cisterna. The number of cisternae the molecule is transported through is therefore directly proportional to the degree of modification it undergoes.
B) Cargo molecules move from one cisterna to the next in an anterograde direction via small vesicles. The processing enzymes that modify the cargo molecules remain in the same cisterna within the stack.
C) Processing enzymes move in a retrograde direction into only the first cisterna, with all subsequent movement external to cisternae and instead occuring via vesicles where processing enzymes are active.
D) Processing enzymes move freely between cisternae and vesicles where they come in to contact with cargo molecules moving from one cisternae to the next.
E) Vesicles and cisternae constantly fuse and divide, by which means they facilitate processing enzymes to contact and interact with cargo molecules as they move in either an anterograde or retrograde direction.

Question 44

Why is the Golgi apparatus, unlike other cellular features, always spelt with a capital letter?

A) It is a cellular feature of particularly crucial importance, signified by its beginning with a capital letter.
B) When first described by Alberto Minguell in 1886, it was accidentally spelt with a capital letter which has carried on into modern literature.
C) It is named after Camillo Golgi, who first identified the Golgi apparatus in 1897.
D) It is an acronym for 'Glucose orthophosphate layers, glyco-transport intracellular'.
E) Golgi is an abbreviation for Golgihexoheptahydratekinase. Scientific terms commonly spelt as an abbreviation have a capital letter to identify it as such.

Question 45

Which of the following is NOT a cargo molecule transported via the Golgi apparatus?

A) Polysaccharides
B) Transcripts
C) Proteins
D) Glycoproteins
E) All options listed here are correct.