FINAL EXAM Flashcards
The genetic material in viruses is composed of: A. DNA B. RNA C. either DNA or RNA D. neither DNA nor RNA E. mitochondria
C
How much of the human genome is thought to be due to insertion by viral DNA? A. 0% B. 0.1-1% C. 5-8% D. 33-35% E. 95-99%
C
What do mitochondria and chloroplasts have that Golgi apparatus and endoplasmic reticulum lack? A. large amounts of catalase B. large amounts of water C. membranes composed of lipids D. DNA E. vesicles
D
Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse? A. rough endoplasmic reticulum B. golgi apparatus C. secretory vesicles D. exterior of the cell E. the nucleus
D
What scientific hypotheses can be tested by a pulse-chase experiment?
A. Solubility of a molecule
B. The amino acid sequence of a protein
C. Movement of molecules through a cell over time
D. The steady-state level of protein in the cell
E. The central dogma of Biology
C
What is the first step in a pulse-chase experiment?
A. Examining cells for the location of the labeled molecules
B. Preparing cells for electron microscopy
C. Incubating cells with an unlabeled molecule
D. Incubating cells with a labeled molecule
E. Breaking the cells open and then spinning them at low speeds
D
Anton Van Leeuwenhoek was the first to A. see vesicles fusing to the plasma membrane of cells B. see autophagy in action C. see individual molecules of DNA D. see proteins E. see organelles
E
Plasmids contain A. lipids B. enzymes that degrade toxic substances C. many ribosomes D. DNA E. microtubules
D
The biological term “flagella” comes from a Greek word meaning A. sweet B. bitter C. whip D. color E. thread
C
Thomas Sudhof, James Rothman and Randy Scheckman were awarded the Nobel Prize in 2013 for their pioneering studies describing
A. How mitochondria and chloroplasts were related
B. how proteins are formed by ribosomes
C. the mechanisms regulating exocytosis
D. the mechanisms involved in extrusion of RNA from the nucleus
E. how enzymes can be inhibited
C
Evidence suggesting that mitochondria were once free-living cells that were engulfed by an ancient eukaryotic cell includes
A. the presence of DNA within the mitochondria
B. the presence of double membranes of mitochondria
C. their ability to make the energy rich compound ATP
D. A & B
E. A, B & C
D
Peroxisomes possess a lot of A. mitochondria B. DNA C. RNA D. sugars E. proteins that degrade H2O2
E
Centrifugation has been used to
A. separate organelles from cells
B. identify the location of proteins using autoradiography
C. identify the location of proteins using fluorescence microscopy
D. define the difference between prokaryotes and eukaryotes
E. study the process of autophagy
A
Microtubules are made of molecules called A. kinesins B. actin C. flagella D. tubulin E. keratin
D
The \_\_\_\_\_ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell. A. cell wall B. pili C. nucleoid region D. plasma membrane E. nuclear pore
D
The preparation of liver mitochondrial enzymes begins by placing liver and a buffered solution in a blender. What is the purpose of the blender?
A. to remove the plasma membranes from the intracellular structures, such as the mitochondria
B. to separate the nuclei from the mitochondria
C. to separate the mitochondria from the other organelles
D. to prepare a cell homogenate; to break open the liver cells and to release the organelles
E. to separate the RNA from the DNA
D
What central theme of biology helps explain why various cells can look so different from one another?
A. All cells need to engage in energy transformations.
B. Information flow in a cell goes from DNA to RNA to protein
C. cell structure is tightly connected with cell function
D. Different cells contain different macromolecules as their genetic material.
E. The split between prokaryotic and eukaryotic cells defines this characteristic
C
Which of these are hollow rods that shape and support the cell? A. actin filaments B. intermediate filaments C. microtubules D. kinesin E. flagella
C
Which type of experiment was critical to showing that kinesin functioned as a transport protein? A. centrifugation B. fluorescent microscopy C. pulse-chase D. acid-induced degradation of proteins E. electron microscopy
B
In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules?
A. To target the proteins to the nucleus
B. To make the proteins bigger
C. To give the protein molecules energy
D. To make the proteins easy to see
E. To slow the proteins down
D
Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results?
A. Nucleoplasmin does not have a nuclear localization signal.
B. One of the fusion proteins entered the nucleus by passive transport
C. The cytoplasmic protein contains a nuclear localization signal.
D. Only one of the two fusion proteins possesses a nuclear localization signal.
E. Nucleoplasmin regulates its own destruction in a cell
D
Liver cells possess many proteins that are required for many functions, including blood clotting factors and proteins that act to degrade a number of substances such as alcohol, insulin and other hormones. Based on this information, one might expect that
A. these cells would have more chromatin than most other cells
B. these cells would have more DNA than most other cells
C. liver cells would have high levels of rough endoplasmic reticulum
D. liver cells would have lots of processing occurring in the smooth endoplasmic reticulum
E. liver cells would have low levels of lysosomes
C
The word “chromosome” was selected by early cell biologists because
A. they looked like threads
B. they looked colorful with the dyes used at the time
C. they were located in the nucleus
D. they were composed of proteins and DNA
E. they were not present in prokaryotic cells
B
What type of bond joins the monomers in a protein's primary structure? A. hydrophobic B. hydrogen bonds C. disulfide bonds D. peptide ponds E. ionic bonds
D