In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is the _____.
size and weight of the component
What clue would tell you if a cell is prokaryotic or eukaryotic?
whether or not the cell is partitioned by internal membranes
Which of the following correctly matches an organelle with its
function?
A. ribosome ... manufacture of lipids
B.
mitochondrion ... photosynthesis
C. lysosome ...
movement
D. nucleus ... cellular respiration
E. central
vacuole ... storage
E. central vacuole ... storage
But remember, plant cells
have a central vacuole, whereas most animal cells have several
smaller vacuoles located throughout the cytoplasm.
All of the following are part of a prokaryotic cell EXCEPT
_____.
A. a plasma membrane
B. ribosomes
C. an
endoplasmic reticulum
D. a cell wall
C. an endoplasmic reticulum
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.
Large numbers of ribosomes are present in cells that specialize in producing which molecules?
proteins
A cell with an extensive area of smooth endoplasmic reticulum is specialized to _____.
synthesize large quantities of lipids
Which organelle plays a role in intracellular digestion?
lysosome
The prefix "lyso-" means decomposition.
The Golgi apparatus has a polarity, or sidedness, to its structure
and function. Which of the following statements correctly describes
this polarity?
A. Transport vesicles fuse with one side
of the Golgi and leave from the opposite side.
B. Lipids in the
membrane of the Golgi may be sorted and modified as they move from
one side of the Golgi to the other.
C. Proteins in the membrane
of the Golgi may be sorted and modified as they move from one side of
the Golgi to the other.
D. All of the listed responses correctly
describe polarity characteristics of the Golgi function.
D. All of the listed responses correctly describe polarity characteristics of the Golgi function.
Which structure is the site of the synthesis of proteins that may be exported from the cell?
rough ER
What is the most likely pathway taken by a newly synthesized protein
that will be secreted by a cell?
A. ER → Golgi →
nucleus
B. ER → Golgi → vesicles that fuse with plasma
membrane
C. Golgi → ER → lysosome
D. ER → lysosomes →
vesicles that fuse with plasma membrane
B. ER → Golgi → vesicles that fuse with plasma membrane
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?
smooth ER
Mitochondria are found in _____.
plant and animal cells
All eukaryotic cells, including
plant and animal cells, contain mitochondria.
Which of the following are common traits of chloroplasts and
mitochondria?
A. Both are found in plant and animal
cells.
B. Both are surrounded by a single membrane.
C. Both
have their own DNA.
D. Both reproduce by meiosis.
E.
Proteins for both are synthesized on ribosomes in the rough ER
C. Both have their own DNA.
Mitochondria and
chloroplasts contain their own DNA and ribosomes.
The evolution of eukaryotic cells most likely involved _____.
A. acquisition of an endomembrane system and subsequent
evolution of mitochondria from a portion of the Golgi
B.
endosymbiosis of an aerobic bacterium in a larger host cell the
endosymbiont evolved into mitochondria
C. anaerobic archaea
taking up residence inside a larger bacterial host cell to escape
toxic oxygen the anaerobic bacterium evolved into chloroplasts
D.
an endosymbiotic fungal cell evolving into the nucleus
B. endosymbiosis of an aerobic bacterium in a larger host cell the endosymbiont evolved into mitochondria
Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the ER?
in mitochondria
Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
components of the cytoskeleton
The cilia and flagella of eukaryotic cells are composed of _____.
microtubules
Eukaryotic cilia and flagella are composed
of microtubules.
Which of the following contain the 9 + 2 arrangement of microtubules,
consisting of nine doublets of microtubules surrounding a pair of
single microtubules?
A. motile cilia and primary
(nonmotile) cilia
B. centrioles and basal bodies
C. basal
bodies and primary (nonmotile) cilia
D. flagella and motile cilia
D. flagella and motile cilia
Amoebae move by crawling over a surface (cell crawling), which involves _____.
growth of actin filaments to form bulges in the plasma membrane
Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the transport process requires energy). Yet, when they put everything together, there was no movement or transport of vesicles. What were they missing?
motor proteins
Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to _____.
move vesicles within a cell
What are the definitions for each of these prefix, suffixes and root
words?
ex-
a- (or an-)
cyte (or cyto-)
endo-
eu-
mito-
chloro-
out of: ex-
without, lack of, not: a- (or an-)
cell: -cyte
(or cyto-)
inside, inner: endo-
true, good: eu-
thread:
mito-
green: chloro-
Which structure is common to plant and animal cells?
A.
centriole
B. central vacuole
C. chloroplast
D. mitochondrion
D. mitochondrion