BIOL 112 CH 6

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the __________.

central vacuole

The _____ is composed of DNA and protein.

chromatin Chromatin is composed of DNA and protein.

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?

motor proteins

Microfilaments function in cell motility including __________.

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

--

--

water: two: across: body: between: little, small: color:

aqu- (or aqua-) bi- trans- -some (or soma-) inter- -elle chrom-

function of lysosomes

macromolecule digestion, autophagy

During muscle contractions, myosin motor proteins move across tracks of

microfilaments

The endoplasmic reticulum is part of the endomembrane system, which also includes the __________.

nuclear envelope, the Golgi apparatus, lysosomes, and vesicles

A substance moving from outside the cell into the cytoplasm must pass through __________.

the plasma membrane

The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic:prokaryotic cells?

1000:1 As the diameter of a cell increases, other dimensions also change. For two cells of approximately equivalent shape but different diameters, surface area increases as the square of diameter, and volume increases as the cube of diameter. Thus, if a eukaryotic cell is ten times the diameter of a prokaryote, its surface area will be one hundred (102) times that of the prokaryote and its volume will be one thousand (103) times that of the prokaryote.

Choose the letter that indicates the organelle that contains most of a cell's DNA.

C

Which of the following is false in respect to cells' chromosomes?

Chromosomes are only visible as a cell is about to divide

Basal bodies are most closely associated with which of the following cell components?

Cilia

Which of these provides the cell with structural support?

D Microfilaments are a component of the cytoskeleton.

Which of these is the double membrane that encloses the nucleus?

E

In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?

Eukaryotic cells are compartmentalized, which allows for specialization.

Select the correct statement describing cellular structure or function.

Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell. Only plant cells contain chloroplasts, and only animal cells contain mitochondria. Plant and animal cells both carry out cellular respiration, producing ATP. Plant and animal cells both carry out cellular respiration, producing ATP All plant and animal cells carry out cellular respiration in mitochondria, producing ATP.

Which statement correctly describes an endomembrane function?

Products of the ER are usually modified during their transit from the cis to the trans region of the Golgi apparatus. The cis and trans regions of the Golgi apparatus act as receiving and shipping departments. As molecules move from the cis to the trans face of the Golgi apparatus, they are usually modified.

Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum

Where is calcium stored?

Smooth ER In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.

What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane?

Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores.

Choose the best description of the cell cytoskeleton.

The cell cytoskeleton is similar to an animal skeleton in providing rigid internal support and structure to the cell. The cell cytoskeleton serves as permanent scaffolding to anchor cell components into position within the cell cytoplasm. The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components. The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components.

route of endomembrane system

The endomembrane system is critical for the synthesis, processing, and movement of proteins and lipids in the cell. The smooth ER functions mainly in lipid synthesis and processing. The rough ER is the site of secretory protein synthesis. These proteins are processed further in the Golgi apparatus, from where they are dispatched in vesicles to the plasma membrane. Lysosomes, whose enzymes and membranes are made and processed by the rough ER and Golgi apparatus, function in the hydrolysis of macromolecules, such as in phagocytosis and autophagy.

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?

The intestinal cells are bound together by tight junctions

Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER).

The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.

The extracellular matrix of the animal cell has all of the following molecular components except __________.

a middle lamella

_____ is/are identical in structure to centrioles.

basal bodies Basal bodies and centrioles have identical structures.

Animal cells have unique organelles called __________ that are composed of structures called __________.

centrosomes; centrioles

chloro- mito- -cyte (or cyto-) eu- a- (or an-) ex- endo-

green: thread: cell: true, good: without, lack of, not: out of: inside, inner:

Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell they __________.

have no membrane-bounded organelles in their cytoplasm

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

in the rough endoplasmic reticulum

The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized __________.

in the rough endoplasmic reticulum and in the Golgi apparatus

Which of the following proteins are synthesized by bound ribosomes?

insulin DNA polymerase lysosomal enzyme ribosomal protein ER protein actin insulin, lysosomal enzyme, and ER protein

Many cell organelles, most notably the nucleus, are anchored by ______ which are assembled from a diverse class of proteins.

intermediate filaments

The extension of pseudopodia in amoeba is due to the regulated assembly and destruction of

intermediate filaments

The network of fibers that organizes structures and activities in a cell __________.

is the cytoskeleton

function of the smooth ER

lipid synthesis, calcium ion storage, and poison detoxification

Centrosomes are sites where protein dimers assemble into

microtubules

The endosymbiont theory explains the origins of __________.

mitochondria and chloroplasts

Which of these organelles carries out cellular respiration?

mitochondrion Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.

The region of a bacterial cell that contains the genetic material is called the __________.

nucleoid

Ribosomal subunits are manufactured by the _____.

nucleolus Ribosomes are manufactured by the nucleolus

eukaryotic cells only

nucleolus, mitochondria, and lysosome

Cells are small because __________.

of the geometric relationships between surface and volume

Which of these organelles produces H2O2 as a by-product?

peroxisome Peroxisomes produce hydrogen peroxide as a by-product of their metabolic processes.

__________ are membrane-bound metabolic compartments that specialize in the production of hydrogen peroxide (H2O2) and its conversion to water.

peroxisomes

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane The plasma membrane regulates the passage of material into and out of the cell.

in both eukaryotic and prokaryotic cells

plasma membrane, ribosomes, and flagella

Which of the following is present in a prokaryotic cell?

ribosomes

_____ are the sites of protein synthesis.

ribosomes Ribosomes are the site of protein synthesis.

Which of these organelles manufactures proteins bound for secretion out of the cell?

rough endoplasmic reticulum The ribosomes associated with the rough ER synthesize secretory proteins bound for the exterior of the cell. Further processing and packaging occurs in the Golgi apparatus.

You would expect a cell with an extensive Golgi apparatus to __________.

secrete a lot of protein

micro- hyper- -plasm -phyll phago- hypo- sym-

small: above, greater than: formed substance: leaf: eat: below, less than: same:

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except __________.

that mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes

Dye injected into a plant cell might be able to enter an adjacent cell through __________.

plasmodesmata

Cell junctions in plant cells are called __________, and communicating junctions in animal cells are called __________.

plasmodesmata; gap junction

Which statement about the cytoskeleton is true?

Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.

In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are

microtubules

Which of these are hollow rods that shape and support the cell?

microtubules Microtubules are rods that also play a role in organelle movement.

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a __________.

human skin cell

function of golgi apparatus

protein modification and sorting, and cisternal maturation

function of the rough ER

protein synthesis

Proteins that are secreted from a eukaryotic cell must first travel through the endomembrane system. Drag the labels onto the diagram to identify the path a secretory protein follows from synthesis to secretion.

protein synthesis -> endoplasmic reticulum -> cis Golgi cisternae -> medial Golgi cisternae -> trans Golgi cisternae -> plasma membrane -> extracellular space

The function of the rough endoplasmic reticulum (RER) is __________.

to synthesize proteins that are secreted as glycoproteins

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.

transferring of information from DNA to messenger RNA Transcription is the first of the two main steps of protein synthesis.

Cell motility, which includes changes both in cell location and in the movement of cell parts, requires interactions of the cytoskeleton __________.

with motor proteins

Which of these structures stores, modifies, and packages products?

a The Golgi apparatus modifies, stores, and packages products of the ER.

prokaryotic cells only

nucleoid