Principles of Biology Ch. 4
Which technique is used to separate different part of cells so that they can be studied by both physical and chemical methods?
Cell fractionation
The smooth ER is the primary site for the synthesis of proteins and cholesterol needed to make membranes.
False
The many short appendages that a cell has are called cilia.
True
The micrometer (μm) is the most convenient unit for measuring cells.
True
What type of microscopy uses a laser to excite fluorophores in a thin "slice" through a cell?
a. confocal microscopy
The ratio of the size of the image seen with the microscope to the actual size of the object is called:
a. magnification
5. A cell is surrounded by which distinctive surface membrane?
a. plasma membrane
Evidence that all living cells have a common origin is best illustrated by
a. the basic similarities in cell structure and chemistry
Almost every vertebrate cell has a primary cilium, a single cilium on the cell surface that serves as a cellular antenna.
b. False
Enzymes called proteases in the ER lumen catalyze folding of proteins into proper conformations.
b. False
Peroxisomes are found in large numbers in cells that synthesize, store, and degrade lipids, and one of their functions is to break down protein molecules.
b. False
4. The accompanying image is the product of which type of microscope?
b. Nomarski differential interference microscope
Plants lack organ systems for disposing of toxic metabolic waste products. Their cells' vacuoles are similar to which animal cell organelle?
b. lysosomes
The smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make ____.
e. cell membranes
What enzyme in the ER lumen catalyzes the efficient folding of proteins into proper conformations?
e. molecular chaperones
What is a characteristic found in both prokaryotic and eukaryotic cells?
e. plasma membrane
Which two organelles are responsible for converting energy into forms that can be used by cells?
mitochondria and chloroplasts
In scanning electron microscopy, an electron beam passes through a very thin slice of a specimen and then falls onto a photographic plate or a fluorescent screen.
False
If a bacterial toxin destroys ribosomes, what cellular activity will be affected first?
a. Protein synthesis
Microfilaments are linked with one another and with other proteins by linker proteins.
a. True
Specialized structures within a living cell are known as
a. organelles.
18. Upon observing a cell of a grass blade, you notice a prominent sac that occupies a large portion of the cell. Which organelle is this?
b. vacuole
Which strategy is the most effective for larger cells to have an effective surface area to volume ratio?
c. having thin, finger-like projections
What does the nucleolus, within the nucleus, synthesize?
d. ribosomal RNA
A basal body anchors what part of a cell?
flagellum
Intermediate filaments are most closely associated with which of the following?
keratins
What is the primary function of mitochondria?
transformation of energy
What is the purpose of the cristae of the inner membrane of mitochondria?
To increase surface area
Which of the following organelles plays an important role in apoptosis, or programmed cell death?
b. mitochondria
DNA is associated with certain proteins, forming a complex called:
b. chromatin