Chapter 4 Notes
One centimeter = ________ millimeters.
10
Which of the following statements about electron microscopes is true?
Electron microscopes focus electron beams to create a magnified image of an object.
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. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.
Which of the following statements about lysosomes is false?
Lysosomes synthesize proteins from the recycled amino acids.
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 about plant cell walls is false?
Plant cell walls protect plant cells by forming an impermeable layer around the cell.
________ cells lack a membrane-enclosed nucleus.
Prokaryotic
Which of the following statements regarding the endomembrane system is false?
The endomembrane system is a system of interrelated membranes that are all physically connected.
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
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
Resolution is the...
ability of an optical instrument to show two close objects as separate.
Which of the following statements regarding cells is false?
all cells have a cell wall
Skin cells are fastened into strong sheets by
anchoring junctions
Dynein feet
are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
In the plasma membrane, the phospholipid heads
are hydrophilic and face outward towards the aqueous solution on both sides of the membraneThis answer is correct.
Microfilaments differ from microtubules in that microfilaments
are mainly composed of actin, whereas microtubules are composed of tubulin
You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells
are plant cells
Which of the following structures are used by prokaryotes for attaching to surfaces?
capsules
A scanning electron microscope is used to study ________, whereas a transmission electron microscope is used to study ________.
cell surfaces . . . internal cell structures
The idea that all living things are composed of cells and that all cells come from other cells defines
cell theory.
The function of mitochondria is
cellular respiration
Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________.
chloroplasts . . . cell walls . . . centrioles
Cilia differ from flagella in that
cilia are typically more numerous and shorter than flagella.
The nucleus of a cell
contains DNA.
The nucleoid region of a prokaryotic cell
contains the cell's DNA
Contractile vacuoles
prevent cells from bursting as a result of the influx of excess water.
Archaea are composed of ________ cells.
prokaryotic
Most animal cells are
embedded in an extracellular matrix.
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
gap junctions
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.
The extracellular matrix attached to cells via glycoproteins that then bind to _______ in the plasma membrane.
integrins
The two main functions of the rough endoplasmic reticulum are the production of
membrane and proteins secreted by the cell.
Secretory proteins are
released from the cell through the plasma membrane.
The endosymbiosis hypothesis is supported by all of the following pieces of evidence, except the fact that
mitochondria use ATP like prokaryotes.
Plasma membranes are permeable to
nonpolar molecules such as CO2
Which of the following structures is exclusively associated with prokaryotic cells?
nucleiod
A bacterial cell's DNA is found in its
nucleoid region
Which of the following cell structures is associated with the breakdown of harmful substances or substances that are no longer needed by the cell?
peroxisomes
Which organelle is involved in the catabolism of fatty acids and the detoxification of alcohol?
peroxosome
The function of chloroplasts is
photosynthesis
Which location in the cell is unlikely to contain ribosomes or ribosomal subunits?
plasma membrane
Intermediate filaments
surround the nucleus
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
Smooth endoplasmic reticulum
stores calcium ions in muscle cells.
The Golgi apparatus..?
stores, modifies, and packages proteins.
The function of the nucleolus is
to manufacture ribosomal RNA.
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
Light microscopes
use light and glass lenses to magnify an image.
As cell size increases, the
volume increases faster than the surface area.