Biology 211

The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____.

C. Plasma Membrane. The plasma membrane is selectively permeable.

What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?

Cell Wall

_____ are found only in plant cells, but _____ are found in both plant and animal cells.

Central vacuoles; ribosomes

The structural framework in a cell is the

Cytoskeleton. The cytoskeleton is the structural framework in a cell ("cyto" refers to cell and "skeleton" refers to a structural framework).

The DNA-containing region of this bacterial cell is indicated by the letter _____.

D. Nucleoid

_____ are surface appendages that allow a bacterium to stick to a surface.

Fimbriae

Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?

Mitochondrion - In both plant and animal cells, it's the mitochondria that convert chemical fuel into packets of chemical energy that can power the cell.

Where is the genetic information of the cell stored?

Nucleus

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

Ribosomes. Ribosomes dock on the rough ER, and proteins are completed inside the rough ER.

One function of the central vacuole in plant cells is facilitating cell growth: the central vacuole absorbs water and increases in size, expanding the volume and size of the plant cell while doing so. Animal cells, however, do not grow by this method. What is an essential difference between animal and plant cells that could explain how a plant cell can withstand this expansion of the central vacuole?

The plant cell wall provides a more rigid structure. The plant cell can use the central vacuole for growth because the cell wall is rigid.

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

They are constructed of interrelated membranes. Each of these organelles is a member of the endomembrane system and is constructed of the same type of membrane.

1 meter = _____ centimeters. a. 100 b. 1,000,000,000 c. 1,000 d. 1,000,000,000,000 e. 1,000,000

a. 100 A centimeter is 1 hundredth of a meter.

A 100 mm x 100 mm x 100 mm cell has a surface area that is _____ and a volume that is _____. When this volume is broken into many smaller cells, that are 10 mm x 10 mm x 10 mm, the sum of the surface areas of the smaller cells is _____ than the surface area of the initial cell. a. 60,000 mm2 ... 1,000,000 mm3 ... larger b. 600 mm2 ... 1,000 mm3 ... larger c. 60,000 mm2 ... 1,000,000 mm3 ... smaller d. 60,000 mm3 ... 1,000,000 mm2 ... smaller

a. 60,000 mm2 ... 1,000,000 mm3 ... larger The smaller cell has a larger surface (600 mm2) to volume (1,000 mm3) ratio. This accounts for why most cells are microscopic. The smaller cell has a larger surface (600 mm2) to volume (1,000 mm3) ratio. This accounts for why most cells are microscopic.

_____ aid in the coordination of the activities of adjacent animal cells. a. Gap (communicating) junctions b. Desmosomes c. Keratin fibers d. Plasmodesmata e. Tight junctions

a. Gap (communicating) junctions Gap junctions allow for the passage of material between cells, thus facilitating communication between these cells.

Mitochondria are found in _____. a. both plant cells and animal cells b. animal cells only c. animal cells and bacterial cells d. plant cells only

a. both plant cells and animal cells Mitochondria are found in nearly all eukaryotic cells.

In plants, __________ are the cell junctions that allow the free exchange of small molecules that assist in communication. In animal cells, similar cell junctions are known as __________. a. plasmodesmata ... gap junctions b. tight junctions ... anchoring junctions c. anchoring junctions ... gap junctions d. plasmodesmata ... anchoring junctions

a. plasmodesmata ... gap junctions Plant cells are interconnected by plasmodesmata, which form tubelike structures that penetrate through the cell walls. Gap junctions are formed by specialized channels found in animal cells. Both Plamodesmata and gap junctions allow the free exchange of small molecules and help coordinate the activities of neighboring cells.

You would expect a cell with an extensive Golgi apparatus to _____. a. secrete a lot of material b. move actively c. perform photosynthesis d. make a lot of ATP

a. secrete a lot of material The Golgi apparatus intercepts ER vesicles, modifies the contents for export, and repackages the material in a Golgi vesicle that can fuse with the plasma membrane.

Which of the following is part of the endomembrane system? a. flagellum b. Golgi apparatus c. cytoskeleton d. mitochondria e. ribosomes

b. Golgi apparatus The endomembrane system includes the ER, the Golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The Golgi apparatus processes and packages proteins.

Which of the following is the correct pairing of a cytoskeletal structure and its approximate diameter? a. actin: 25 nm b. microtubules: 25 nm c. intermediate filaments: 5 nm d. microtubules: 7 nm

b. microtubules: 25 nm Mictotubules, with an approximate diameter of 25 nm, are the thickest cytoskeletal fiber. They help shape and support the cell, serve as tracks for protein movement, guide the movements of chromosomes in cell division, and are the main components of cilia and flagella.

Which of the following developments might have contributed to mitochondria becoming endosymbionts in eukaryotic cells? a. circular DNA in both mitochondria and chloroplasts b. the increasing availability of atmospheric oxygen c. the decreasing availability of atmospheric oxygen d. the presence of chloroplast in cells

b. the increasing availability of atmospheric oxygen As Earth's atmosphere became increasingly oxygen-rich, cells had a survival advantage if they could benefit from an endosymbiont that could use oxygen to release energy. This is the role of mitochondria in eukaryotic cells.

Which of these cell junctions form a barrier to the passage of materials? a. desmosomes (anchoring junctions) b. tight junctions c. plasmodesmata d. gap (communicating) junctions e. keratin fibers

b. tight junctions Tight junctions form a barrier that prevents fluids from moving between cells.

In the most general sense, which of the following is the correct description of cellular respiration? a. oxygen and ATP are used: carbon dioxide is released b. oxygen and carbon dioxide are released, ATP is created c. oxygen is used, carbon dioxide is released, ATP is created d. oxygen is used, carbon dioxide and ATP are released

c. oxygen is used, carbon dioxide is released, ATP is created Cellular respiration, which occurs in mitochondria, uses oxygen, releases carbon dioxide, and creates ATP, the fuel for cellular work.

Pancreatic cells produce large amounts of protein. About how many ribosomes would you expect there to be in a pancreatic cell? a. about ten b. one c. several million d. several hundred

c. several million There are several million ribosomes in cells, such as the cells in the pancreas that produce digestive enzymes.

Which of the following describes the function of the chloroplast? a. The chloroplast serves as a protein manufacturing facility. b. The chloroplast creates internal pressure for a cell. c. The chloroplast stores compounds produced by the cell. d. The chloroplast converts light energy to chemical energy. e. The chloroplast functions as the site of lipid synthesis.

d. The chloroplast converts light energy to chemical energy.

Which of the following organelles breaks down worn-out organelles? a. Golgi apparatus b. rough endoplasmic reticulum (ER) c. smooth endoplasmic reticulum (ER) d. lysosomes e. mitochondria

d. lysosomes Lysosomes contain digestive enzymes and break down worn-out organelles.

In plants, chlorophyll molecules are located within sacs called __________, which in turn are suspended in the __________ of the __________. a. chloroplasts; stroma; plant cell b. chloroplasts; thylakoid; plant cell c. thykaloid; stroma; mitochondrion d. thykaloid; stroma; chloroplast

d. thykaloid; stroma; chloroplast The inner membrane of the chloroplast contains a thick fluid called the stroma. Within this, a network of sacs called thylakoids is suspended. These sacs are interconnected and sometimes stacked like poker chips.

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic? a. the presence or absence of ribosomes b. whether or not the cell contains DNA c. the presence or absence of a rigid cell wall d. whether or not the cell is partitioned into compartments by internal membranes

d. whether or not the cell is partitioned into compartments by internal membranes Prokaryotic cells lack any internal membranous compartmentalization whereas eukaryotic cells have membrane-bound organelles.

The primary role of _____ is to bind animal cells together. a. tight junctions b. gap (communicating) junctions c. the cytoskeleton d. plasmodesmata e. desmosomes

e. desmosomes The primary role of desmosomes (anchoring junctions) is to bind cells together.

Where in a cell is ATP made?

mitochondria -ATP is made in mitochondria.

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane

What is the function of a bacterium's capsule?

protection -A bacterium's capsule has a protective role.

In a bacterium, where are proteins synthesized?

ribosomes -Ribosomes are involved in the manufacture of polypeptides (proteins).

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER)

Lysosomes are derived from __________ and function in __________.

the Golgi apparatus and rough endoplasmic reticulum ... digestion of worn-out organelles Lysosomes are membrane-enclosed sacs of hydrolytic enzymes that are used to digest macromolecules. They are produced by budding off the Golgi apparatus.

Where is a bacterial cell's DNA found?

nucleoid region -Bacteria lack a nucleus; their DNA is found in the nucleoid region.

The genes for actin are said to be highly conserved. What does this mean? a. The actin gene is similar across many species b. The actin gene is well protected c. The actin gene is relatively easy to identify d. The actin has undergone many changes in evolution

a. The actin gene is similar across many species The term refers to the similarity of the actin gene in many species over evolutionary time.

When you hear the terms contractile, digestive, storage, pigment and poisonous, which of the following organelles comes to mind? a. Vacuole b. chloroplast c. peroxisome d. mitochondrion

a. Vacuole Vacuoles perform all of the listed roles, depending on the type of cell they are in. In plants and fungi, vacuoles perform a digestive function. In some protists, contractile vacuoles circulate water throughout the organism. Protein storage vacuoles in plant seeds, pigment vacuoles in flower petals, and vacuoles containing poisonous substances to ward off animals, are other examples.

Imagine that you fill a basketball with as many ping pong balls as possible. The volume of the basketball is __________ the total volumes of all the ping pong balls. The surface area of the basketball is __________ than the total surface areas of all the ping pong balls. a. approximately equal to; less than b. less than; greater than c. approximately equal to; greater than d. greater than. less than

a. approximately equal to; less than Because the ping pong balls fit into the basketball, they have about the same volume as the basketball. However, the total surface area of all the ping balls will be much greater than the surface area of the basketball.

__________ is the most prevalent glycoprotein in the extracellular matrix a. collagen b. hemoglobin c. integrin d. enzyme

a. collagen Collagen can comprise 40% of the protein in your body.

Which technique allowed scientists to figure out that all cells, and not just muscle cells, contained actin filaments? a. electron microscopy b. light microscopy c. immunofluorescence microscopy d. molecular cytochemistry

a. electron microscopy In the 1960s, staining actin filaments and visualizing them with an electron microscope allowed scientists to discover that these structures are present in all cells

Which listed tissue type would you expect to contain a large proportion of anchoring junctions? a. skin b. brain c. digestive tract tissue d. root tissue

a. skin Anchoring junctions are most plentiful in tissue that will be stretched or stressed. Skin undergoes both stretching and stress as part of normal wear-and-tear.

Pancreatic cells produce large amounts of enzymes for export into the digestive system. By contrast, muscle cells do NOT export digestive enzymes. How do you think that the number of ribosomes compares in the two cell types? a. the pancreatic cell has many more ribosomes than the muscle cells b. the muscle call has many more ribosomes than the pancreatic cell. c. both cell types have about the same number of ribosomes d. neither cell type has many ribosomes

a. the pancreatic cell has many more ribosomes than the muscle cells There are several million ribosomes in cells like those in the pancreas that produce digestive enzymes. The main job of the muscle cell is contraction, not protein synthesis, so it needs far fewer ribosomes.

Which of the following is a function of the central vacuole? a. Converting light energy to chemical energy b. Storing compounds produced by the cell c. Storing the genetic information of the cell d. Separating the cell from its surroundings e. Working with mRNA to synthesize proteins

b. Storing compounds produced by the cell

Lysosomal storage diseases are rare in the general population. Why? a. These diseases are not contagious b. Such diseases are usually fatal in early childhood c. people with such diseases rarely reproduce d. excess lysosomal enzymes attack the reproductive system.

b. Such diseases are usually fatal in early childhood Lysosomal storage diseases result from the absence of key digestive enzymes normally present in lysosomes. Without these enzymes, undigested material builds up and interferes with the cell's function. The damage is so extensive that most people with such disorders die at a very early age.

What feature of the mitochondrion enhances cellular respiration? a. intermembrane space b. cristae c. its DNA d. matrix

b. cristae This is the term for the extensively folded inner mitochondrial membrane. The folding increases the surface area of the membrane, allowing more proteins to be embedded and thus enhancing the ability of the mitochondrion to produce ATP in cellular respiration.

In which of the following ways do lysosomes work within animal cells? a. lysosomes fuse with food vacuoles, digest food and release nutrients into the bloodstream b. lysosomes fuse with food vacuoles, digest food and release nutrients into the cytosol c. lysosomes contain detoxifying enzymes that convert some substances to less harmful ones. d. lysosomes circulate in blood, where they digest food particles

b. lysosomes fuse with food vacuoles, digest food and release nutrients into the cytosol'

When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably __________. a. mitochondria b. microtubules c. cell junctions d. rough endoplasmic reticulum

b. microtubules Microtubules are cytoskeletal components, and the shape of a cell is determined by its cytoskeleton.

Men with primary ciliary dyskinesia (PCD) have recurrent respiratory tract infections and immotile sperm. What is the cause of these symptoms? a. insufficient mitochondria b. excess dynein proteins c. a lack of dynein proteins d. lack of actin proteins

c. a lack of dynein proteins In PCD, dynein, a motor protein, is lacking. Dynein is attached to the outer microtubules in eukaryotic cilia and flagella. Without it, the structures cannot bend. And without bending, cilia lining the trachea (windpipe) cannot sweep out mucus and debris, and sperm cannot travel to the ovum to fertilize it.

The most abundant glycoprotein in the extracellular matrix (ECM) is __________. This protein attaches to __________, which are proteins in the plasma membrane that connect the ECM with the inside of the cell. a. collagen; dyneins b. microfilaments; dynein c. collagen; integrins d. microtubules; integrins

c. collagen; integrins Collagen is the most abundant glycoprotein in the extracellular matrix, as well as accounting for about 40% of the protein in the entire body. Integrins are membrane-spanning proteins that transmit signals between the ECM and the cytoskeleton, where they attach to intercellular microfilaments.

A white blood cell is 12-15 µm (microns) in diameter. If you wished to count the white blood cells in a blood sample, which type of microscope would you choose? a. contrast Microscope b. transmission electron microscope c. light microscope d. scanning electron microscope

c. light microscope Most plant and animal cells can be observed with a light microscope. This level of magnification is sufficient for visualizing a field of cells that are as large as white blood cells

Mitochondria appear in the greatest numbers in cells that are _____. a. undergoing cell division b. reproducing c. metabolically active d. dead

c. metabolically active Mitochondria are the sites of cellular respiration, the catabolic process that generates ATP by extracting energy from food molecules, with the help of oxygen.

Which of the following is the correct pairing of a microscopic structure and its approximate size? a. nucleus: 1 mm b. protein: 10 c. mitochondrion: 1 micrometer d. chicken egg: 10 micrometer

c. mitochondrion: 1 micrometer Mitochondria are cellular organelles that are about 1 µm in diameter. They fit inside cells, which can be as large as 100 µm.

Digestive cells produce and secrete many enzymes that break down ingested food. These cells have a large number of ribosomes __________. a. in the cytoplasm b. on the Golgi apparatus c. on the rough endoplasmic reticulum d. on the smooth endoplasmic reticulum

c. on the rough endoplasmic reticulum The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.

Flagella and cilia are both composed of tubulin subunits. Despite this similarity, key differences exist between these two structures. For example, __________. a. only flagella have the 9 + 2 pattern of microtubules b. only flagella are responsible for movement of single cells c. only cilia move as a coordinated team d. cilia are typically longer than flagella

c. only cilia move as a coordinated team Cilia work together in a coordinated team, much like the oars on a rowing team. This allows them to propel fluids along their surfaces for locomotion or feeding.

A transport vesicle within a cell can contain which of the following? a. a newly made glycoprotein b. digestive enzymes c. a glycoprotein with its attached phosphate group d. a newly made glycoprotein, as well as the glycoprotein with its attached phosphate groups

d. a newly made glycoprotein, as well as the glycoprotein with its attached phosphate groups Transport vesicles are used for two export functions. First, a protein is exported from the rough endoplasmic reticulum after its manufacture, to the Golgi apparatus, where it will be modified for export from the cell via the cell membrane. Such a modification can include the addition of phosphate groups. (Some proteins will remain within the cell.)

You, suddenly grown very small because you drank too much TinyMe, are standing between two cells in the trunk of the oak tree behind your apartment. Your feet are stuck in __________. After you free your feet, what is the first barrier that you must cross to enter any of the surrounding cells? a. actin; secondary cell wall b. dynein; the primary cell wall c. pectin; secondary cell wall d. pectin; primary cell wall

d. pectin; primary cell wall The sticky polysaccharide between cells in plants is pectin, used to thicken jams and jellies. The primary cell wall is the most external part of the cell wall, and the strong secondary cell wall in wood lies next to the plasma membrane. (Of course, you could always slog ahead to find a plasmodesma to enter the cell).

Of the following organelles, which group is involved in manufacturing the substances needed by the cell? a. lysosome, vacuole, ribosome b. vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum c. smooth endoplasmic reticulum, ribosome, vacuole d. ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum

d. ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum Each structure is capable of synthesis.

The cilia and flagella of eukaryotic cells are composed of _____.

microtubules Eukaryotic cilia and flagella are composed of microtubules.

After their synthesis, proteins are modified and sorted by __________ located in the cell's __________. An example of such a modification is __________. a. the golgi apparatus, nucleus, denaturation b. the ribosomes, cytoplasm, adding more amino acids c. the rough endoplasmic reticulum, cytoplasm, adding a phosphate group d. the golgi apparatus, cytoplasm, adding a phosphate group

d. the golgi apparatus, cytoplasm, adding a phosphate group Proteins are synthesized on ribosomes on the rough endoplasmic reticulum, and then taken by a transport vesicle to the Golgi apparatus in the cell's cytoplasm. After incorporation into the Golgi apparatus, the protein may be modified by adding phosphate groups or altering its carbohydrate portions. It is then removed from the Golgi apparatus by a transport protein or incorporated into the plasma membrane of another organelle.

The plant cell wall a. regulates the composition of the cytoplasm. b. makes food by converting light energy to chemical energy. c. is found just inside the plasma membrane. d. is very similar to the animal cell wall. e. is a protective structure made of cellulose fibrils.

e. is a protective structure made of cellulose fibrils.

What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?

increased levels of endoplasmic reticulum activity The smooth endoplasmic reticulum of liver cells has enzymes that are involved in alcohol metabolism. This organelle is affected in the liver cells of alcoholics.

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA The "m" in mRNA stands for "messenger"; mRNA is the messenger that carries genetic instructions from the nucleus to the cytoplasm.

The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.

plasma membrane