Bio Test 2
All of the following are part of a prokaryotic cell except.
B. endoplasmic reticulum
C. plasma membrane
E. cell wall
Under which os the following conditions would you expect to find a cell with a predominance of free ribosomes?
A. a cell that is secreting proteins
B. a cell that is enlarging its vacuole
C. a cell that is constructing its cell wall or extracellular matrix
D. a cell that is digesting food particles
E. a cell that is producing cytoplasmic enzymes
Which organelle is primarily involved in the synthesis of lipids?
B. contractile vacuole
D. smooth endoplasmic reticulum
Which structure is the site of the synthesis of proteins that may be exported form the cell?
B. tight junctions
C. golgi vesicles
E. ribosomes on the rough ER
The golgi apparatus has a polarity of sidedness to its structure and function. Which of the following statements correctly describes this polarity?
A. Soluble proteins in the cistern(interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
B. Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other
C. Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
D. All of the above correctly described polar characteristics of the Golgi function.
In animal cells, hydrolytic enzymes are packaged into an organelle to prevent general destruction of cellular components. Which of the following organelles functions as this compartmentalization?
C. central vacuole
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?
A. Golgi Apparatus
B. Nuclear Envelope
C. smooth ER
D. Transport Vesicles
E. Rough ER
Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen, and generate hydrogen peroxide in the process?
C. Golgi apparatus
Grana, thylakoids, and storm are all components found in
Organelles other than the nucleus that contain DNA include
D. B and C only
E. A, B, and C
Motor proteins provide for molecular motion in cells by interaction with what types of cellular structures?
B. sits of energy production in cellular respiration
C. cellulose fibers in the cell wall
D. membrane proteins
Which of the following contain the 9+2 arrangement of microtubules?
D. A and C only
E. A, B, and C
Which of the following statements about the cytoskeleton is true?
A. Transport vesicles among the membranes of the ensomembrance systems produce the cytoskeleton.
B. Microfilaments are structurally rigid and resist compression, while microtubules resists tension.
C. The dynamic aspect of cytoskeletal function is made possible by the assembly and disassembly of a large number of complex proteins into larger aggregates.
D. Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
E. Chemicals that block the assembly of the cytoskeleton would cause little effect on the cellular functions
Which of the following relationships between cell structures and their respective functions is correct?
A. chloroplasts; chied sites of cellular respiration
B. cell wall; support, protection
C. chromosomes; cytoskeleton of the nucleus
D. lysosomes; formation of ATP
E. ribosomes; secretion
Microfilaments are well known for their role in which of the following?
A. contracting of muscle cells
B. formation of contractile ring to aid division of animal cells
C. cytoplasmic streaming in plant cells
D.A and B only
E. A, B, and C
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
C. gap junctions
D. tight junctions
E. extracellular matrix
Of the following molecules of the ECM, which is capable of transmitting signals between the ECM and the cytoskeleton?
C. middle lamella
Which statement correctly characterizes bound ribosomes?
A. Bound and free ribosomes are structurally different
B. Bound ribosomes generally synthesize membrane proteins and secretary proteins
C. Bound ribosomes are enclosed in their own membrane
D. The most common location for bound ribosomes is the cytoplasmic surface of the plasma membrane.
E. All of the Above
Cell of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking a glycoprotein secreted by pancreatic cells. What is its most likely pathway?
A. Golgi > ER > lysosome
B. nucleus > ER > Golgi
C. ER > Golgi > vesicles that fuse with plasma membrane
D. ER > Golgi > nucleus
E. ER > lysosomes > vesicles that fuse with plasma membrane
Which of the following traits do archaeans and bacteria share?
1. composition of the cell wall
2. presence of plasma membrane
3. lack of a nuclear envelope
4. identical rRNA sequences
A. 2 and 4
B. 1 only
C. 1 and 3
D. 2 and 3
E. 3 only
Which of the following types of molecules are the major structural components of the cell membrane?
A. glycoproteins and cholesterol
B. phospholipid and proteins
C. proteins and cellulose
D. nucleic acids and proteins
E. phospholipids and cellulose
According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?
A. The can move laterally along the place of the membrane
B. The are free to depart from the membrane and dissolve in the surrounding solution.
C. The frequently flip-flop from one side of the membrane to the other.
D. They have hydrophilic tails in the interior of the membrane.
E. The occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane
Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
A. The double bonds result in shorter fatty acid tails and thinner membranes.
B. Can't read
C. Unsaturated fatty acids have a higher cholesterol content and ......in membranes
D. Unsaturated fatty acids permit more water in the interior of the membrane
E. The doubles bonds block interaction among the hydrophilic head groups of the lipids.
Which of the following is true of integral membrane proteins?
A. There are not mobile within the bilayer
B. They are usually transmembrane proteins
C. They are loosely bound to the surface of the bilayer
D. They serve only a structural role in membranes
E. They lack tertiary structure
Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different tack, well before relevant data from molecular systematics became available?
A. Some have cell walls only for support.
B. Some have cell walls only to control osmotic balance.
C. Some have cell walls only for protection from herbivores.
D. Their cell walls are composed of very different molecules.
E. Some closely resemble animals, which lack cell walls.
What kinds of molecules pass through a cell membrane most easily?
A. large polar
B. small and hydrophobic
C. monosaccharides such as glucose
E. large and hydrophobic
Which of the following statements is correct about diffusion?
A. It requires an expenditure of energy by the cell
B. It is a passive process in which molecules move for a region of higher concentration to a region of lower concentration.
C. It is an active process in which molecules move from a region of lower concentration to one of higher concentration.
D. It is very rapid over long distances
E. It require integral proteins in the cell membrane
A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probably result of this transfusion.
A. It will have no unfavorable effect as long as the water is free of viruses and bacteria
B. The patient's red blood cells will swell because the blood fluid is hypotonic compared the the cells.
C. The patient's red blood cells will swell because the flood fluid is hypotonic compared to the cells.
D. The patients red blood cells will swell because the blood fluid is hypertonic compared to the cells
E. The patients red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this, we can deduce that the ells of the celery stalks are
A. isotonic with fresh water but hypotonic to the salt solution.
B. hypotonic to both fresh water and the salt solution
C. hypertonic to fresh water but hypotonic to the salt solution
D. hypotonic to fresh water but hypertonic to the salt solution
E. hypertonic to both fresh water and the salt solution
What are the membrane structures that function in active transport?
A. peripheral proteins
D. intergral proteins
E. cytoskeleton filaments
Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells?
B. active transport pumps
D. facilitated diffusion
E. simple diffusion
White blood cells engulf bacteria through what process?
B. receptor-mediated exocytois
In receptor-mediated endocytosis, recepto molecules initially project to the outside of the cell. Where do they end up after endocytosis?
A. on the ER
B. on the inside surge of the cell membrane
C. on the outer surface of the nucleus
D. on the inside surface of the vesicle
E. on the outside of vesicles
Which of the following factors would tend to increase membrane fluidity?
A. a greater proportion of saturated phospholipids
B. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses
C. a greater proportion of unsaturated phopholipids
D. a relatively high protein content in the membrane
E. a lower temperature
The potassium ion concentration inside the cell is higher than that at the outside of the cell. The moment of potassium into an animal cell requires.
A. a gradient of protons across the plasma membrane
B. low cellular concentrations of sodium
C. high cellular concentrations of potassium
D. active transport that needs energy source such as ATP
E. a cotransport protein.
A signaling molecule usually small in size that specifically binds to another molecule called receptor.
A. usually terminates a signal reception
B. is called a ligand
C. is called a signal transducer
D. seldom is involved in hormonal signaling.
E. is called a polymer
One of the major categories of receptors in the plasma membrane reacts by forming dimmers, adding phosphate groups, then activating relay proteins. Which type of receptor is this?
A. G protein-linked receptor
B. receptor tyrosine kinases
C. steroid receptors
D. steroid receptors
E. ligand-gated ion channels
What would be true for the signaling system in an animal cell that lacks the ability to produce GTP?
A. It would be able to carry out reception and transduction, but would not be able to ..... a signal
B. It would not be able to activate and inactivate the G protein on the cytoplasmic sid..... plasma membrane
C. It could activate only the epinephrine system.
D. Only A and C are true
E. A, B, and C are true
Binding of a signaling molecule to which type o receptor leads directly to a cha......distribution of ions on .....of the membrane
A. receptor tyrosine kinases
B. ligand-gated ion channels
C. G protein-coupled receptors
D.phosphorylated receptor.... kinase dimer
E. intracellular receptor
Chemical signal pathways
A. often involve the binding of signal molecules to a protein on the surface of a target cell.
B. are absent in bacteria, but are plentiful in yeast
C. operate in animals, but not in plants
D. use hydrophillic molecules to activate enzymes
E. involved the release of hormones into the blood
Which of the following chemical messengers that pass through the plasma membrane of cells have receptor molecules in the cytoplasm?
From the perspective of the cell receiving the message, the three stages of cell signaling are
A. the alpha, beta, and gamma stages
B. the paracrine, local, and synaptic stages
C. signal reception, cellular response, and cell division
D. signal reception, signal transduction, and cellular response
E. signal reception, nucleus disintegration, and new cell generation
A. occurs only in paracrine yeast cells
B. involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid.
C. involves mating factors attaching to target cells and causing production of new paracrine cells.
D. has been found in plants but not animals