74 terms

Chapter 4- Tour of the Cell

The function of the nucleolus is
to manufacture ribosomal RNA
A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding?
A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
Which of the following statements about the cytoskeleton is false?
Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
Which of the following statements regarding cells is false?
All cells have a cell wall
The function of chloroplasts is
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?
a light microscope because it allows observations of whole, live cells
Which of the following statements about cellular metabolism (the breaking down & building of molecules) is false?
Cellular metabolism occurs in animal but not plant cells
Which of the following structures is exclusively associated with prokaryotic cells?
Long fibers of DNA and protein are called
The idea that all living things are composed of cells and that all cells come from other cells defines
cell theory
Cilia differ from flagella in that
cilia are typically more numerous andshorter than flagella
A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they
have gained water and burst
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?
Keep the cough drop whole.
________ cells lack a membrane-enclosed nucleus.
Which of the following structures are used by prokaryotes for attaching to surfaces?
Archaea are composed of _______ cells
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell?
rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
The nucleoid region of a prokaryotic cell
contains the cell's DNA
The diameter of most animal and plant cells ranges from
10 to 100 micrometers
The nucleus of a cell
contains DNA
The cells that produce hair contain a lot of ______, while the cells that produce the oils that coat the hair contain a lot of _______.
rough endoplasmic reticulum... smooth endoplasmic reticulum
A scanning electron microscope is used to study ____, whereas a transmission electron microscope is used to study _____.
cell surfaces... internal cell structures
Unlinke animal cells, plant cells have _____ and ______. Unlike plant cells, animal cells have ______.
chloroplasts... cell walls... centrioles
Light microscopes
use light and glass lenses to magnify an image
The oil from the sebaceous glands is produced by which of the following cell organelles?
smooth endoplasmic reticulum
One centimeter = _______ millimeters
Which of the following statements about cells is true?
All cells have internal structures that move.
The membranous compartmentalization of a cell
allows different metabolic processes to occur simultaneously
Microfilaments differ from microtubules in that microfilaments
are mainly composed of actin, whereas microtubules are composed of tubulin
DNA synthesis; RNA synthesis; assembly of ribosomal subunits (in nucleoli)
polypeptide (protein) synthesis
Rough ER
synthesis of membrane proteins, secretory proteins, and hydrolytic enzymes; formation of transport vesicles
Smooth ER
lipid synthesis; carbohydrate metabolism in liver cells; detoxification in liver cells; calcium ion storage
Golgi apparatus
modification, temporary storage, and transport of macromolecules; formation of lysosomes and transport needs
digestion of nutrients, bacterian, and damaged organelles; destruction of certain cells during embryonic development
diverse metabolic processes, with breakdown of H2O2 by-product
digestion (like lysosomes); storage of chemicals; cell enlargement; water balance
conversion of light energy to chemical energy of sugars
conversion of chemical energy of food to chemical energy of ATP
maintenance of cell shape; anchorage for organelles; movement of organelles within cells; cell movement; mechanical transmission of signals from exterior of cell to interior
Cell walls
maintenance of cell shape and skeletal support; surface protection; binding of cells in tissues
Extracellular matrix
binding of cells in tissues; surface protection; regulation of cellular activities
Cell junctions
communication between cells; binding of cells in tissues
Which of the following cells has the greatest surface area-to-volume ratio?
As cell size increases, the
volume increases faster than the surface area
The Golgi apparatus
stores, modifies and packages proteins
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation
will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs
The function of mitochondria is
cellular respiration
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
communicating junctions
Smooth endoplasmic reticulum
stores calcium ions in muscle cells
Which of the following statements about electron microscopes is true?
Electron microscopes focus electron beams to create a magnified image of an object.
A bacterial cell's DNA is found in its
nucleoid region
Mitochondria differ from chloroplasts in that mitochondria
contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana
When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will
undergo self-digestion and die
Contractile vacuoles
prevent cells from bursting as a result of the influx of excess water
The endosymbiosis hypothesis proposes that
a small cell lived inside a larger cell to the benefit of both cells
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which one of the following instruments would be best?
a scanning electron microscope
Skin cells are attached to each other by
tight junctions
Which of the following statements regarding the Golgi apparatus is false?
The Golgi apparatus decreases in size when a cell increases its protein production.
Which of the following statements about the functions of a plant cell central vacuole is false?
The central vacuole of a plant cell may digest chemicals for recycling.
The stroma is the
thick fluid enclosed by the inner chloroplast membrane
Plasma membranes are permeable to
nonpolar molecules such as CO2
Which part of the mitochondrion shown is its matrix?
structure E
Which of the following cell structures is associated with the breakdown of harmful substances or substances that are no longer needed by the cell?
The plasma cell produces thousands of antibodies per second. What type of intracellular structure would you expect to be very prominent within the cell?
endoplasmic reticulum
Resolution is the
ability of an optical instrument to show two close objects as seperate
Which of the following statements about lysosomes is false?
Lysosomes synthesize proteins from the recycled amino acids
A drug that interferes with microtubule formation is likely to completely disrupt
the movements of sperm cells
Unlike animal cells, plant cells have _______ and _________. Unlike plant cells, animal cells have _________.
chloroplasts... cell walls... centrioles
Tay-Sachs disease results from the malfuction of
The two main functions of the rough endoplasmic reticulum are the production of
membrane and proteins secreted by the cell
During cell reproduction, chromatin fibers coil up into structures called
Which of the following statements regarding plasmodesmata is false?
Plasmodesmata are commonly found in single-celled organisms
Secretory proteins (proteins that are secreted by a cell) are
released from the cell through the plasma membrane