Exam 3 Biology
Which of the following would be able to pass freely through a plasma membrane?
CO 2 Response Feedback:The only molecules that can move easily through the plasma membrane are ones that are small and hydrophobic, like CO 2.
When a car burns gasoline, much of the energy is released in the form of heat. Which of the following best describes this process in relation to the first law of thermodynamics?
Energy can be changed from one form to another. Response Feedback:The first law of thermodynamics states that energy cannot be created or destroyed but can be changed from one form of energy to another. The potential energy stored in the gasoline is lost as heat as the car converts it into the kinetic energy of motion.
Which statement most accurately describes the second law of thermodynamics?
Energy cannot be changed from one form to another without a loss of usable energy. Response Feedback:The second law of thermodynamics tells us energy cannot be changed from one form to another without a loss of usable energy.
Where do the vesicles that are being made for secretion from the cell become modified and packaged?
Golgi apparatus Response Feedback:All choices are involved in the endomembrane system, but it is the Golgi apparatus that modifies the products, sorts them, and packages them into final vesicles for export from the cell.
Which energy association is correct?
Kinetic energy is energy of motion. Response Feedback:Kinetic energy is the energy of motion. Water stored behind a dam is potential energy, which does not have to be used immediately. Energy in chemical bonds is chemical energy. Light energy is a form of solar energy.
Which is the most common type of intercellular junction between cells of the bladder?
Response Feedback:Adhesion junctions are the most common type of intercellular junction between cells of the bladder. Gap junctions are common among heart cells and smooth muscle. Tight junctions are common in the intestines. Plasmodesmata are found connecting plant cells.
When a potted houseplant is wilting, the addition of water quickly changes the look of the plant. This can be accounted for by which of the following statements?
Response Feedback:Cells placed in a hypotonic solution gain water. Outside the cell, the concentration of water is greater than inside the cell. The cell's central vacuole will gain water and push against the cell wall making it become turgid. When all of the plant's cells experience this water gain the wilted plant becomes firm.
Which of the following is not a type of intracellular protein?
Response Feedback:Intracellular proteins are comprised of an assorted number of protein filaments and tubules including actin, myosin, microtubules, and keratin among others. Cellulose is a polysaccharide form of carbohydrate that is a principle component to cell walls.
As a molecule moves through the plasma membrane it passes through,
Response Feedback:The phospholipid bilayer is arranged with the hydrophilic heads facing outward or inward into the aqueous solutions inside and outside the cell with the hydrophobic tails of the two layers pointing toward each other and excluding water from this area.
There is an antibiotic called streptomycin that doctors prescribe for infection. The antibiotic combines with the bacteria's ribosomes causing them to lose their function. Consequently, the cells die and the person gets better. In other words, the antibiotic destroys bacteria by
Ribosomes function as the site of protein synthesis. The bacterial cells will consequently die as they are unable to produce necessary proteins.
Which of the following is not an example of osmosis?
Sugar in coffee dissolves. Response Feedback:Sugar dissolving in coffee is an example of simple diffusion moving the sugar molecules from high to low concentration. All of the other examples influence the movement of water in and out of cells across their plasma membranes, which are examples of osmosis in action.
ATP releases energy when
a phosphate is removed. Response Feedback:ATP stores energy that can be used in a coupled biological reaction that requires energy. To do this ATP loses the last phosphate group converting the molecule to ADP & P.
Resolving power is the
ability to tell two points apart as separate points. Response Feedback:Resolving power is a feature of microscopes that identifies the level available to distinguish separate structures while viewing.
Which of the following is not a function of the endomembrane system?
acts as the control center of the cell Response Feedback:The endomembrane system is a complex system that moves cellular materials that were either manufactured or taken in by the cell. In this journey the materials can be modified, digested, and packaged for some other destination in or out of the cell.
A cell being observed under a microscope has a cell wall, plasma membrane, ribosomes, and chromosomal material that is not found in a nucleus. Based on this information, the cell could be a
bacterial cell. Response Feedback:Bacterial anatomy is representative of prokaryotic cell structure, which lacks a membrane-bound nucleus or other membrane-bound organelles.
Because it is a passive process, which membrane transport process can continue whether the cell is alive or dead?
diffusion Response Feedback:Diffusion is the only process that does not require energy, so it would occur in a nonliving cell.
A prokaryotic cell
does not have a membrane-bound nucleus. Response Feedback:A prokaryotic cell does not have a membrane-bound nucleus. The DNA of prokaryotic cells is located in a region of the cytoplasm called the nucleoid region.
Which of the following is not a mechanism used to move materials in and out of the cell?
feedback inhibition Response Feedback:The plasma membrane regulates the passage of molecules into and out of the cell. Some of the key mechanisms include facilitated diffusion, osmosis, phagocytosis, pinocytosis, and active transport.
Without tight junctions in certain tissues,
fluids may leak out past the barrier the junction would create. Response Feedback: Tight junctions between cells serve as impermeable barriers because their adjacent plasma membranes are joined.
Energy of activation
is the energy required for molecules to react with each other. Response Feedback:The energy of activation is the energy needed to cause molecules to react with one another. Enzymes lower the amount of energy required for a reaction to occur by bringing the substrates into contact.
Enzymes are able to speed up the rate of a reaction by
lowering the energy needed for the reaction to proceed. Response Feedback:Enzymes are able to overcome the energy needed to start a reaction, called the energy of activation. By doing this, they make reactions happen more readily.
Which of the following organelles is not involved in producing substances needed by a cell?
lysosome Response Feedback:Lysosomes are vesicles produced by the Golgi apparatus that serve to digest molecules or portions of the cell itself. They have no production capabilities of their own.
Which of the following is a byproduct of photosynthesis that is used during cellular respiration?
oxygen Response Feedback:Oxygen is the only byproduct of photosynthesis that is then used during cellular respiration.
The nucleus has a double membrane that encloses the DNA. Inside the nucleus, the DNA acts as the template to produce mRNA and ribosomes. To exit the nucleus, these molecules must
pass through pores that span both membranes. Response Feedback:Nuclear pores connect the inside of the nucleus to the cytoplasm and are of a sufficient diameter to allow the passage of mRNA and ribosomes.
Which of the types of cellular activities listed below would not use ATP?
passive transport Response Feedback:Cells use ATP to carry out nearly all of their activities including active transport, muscle contraction, flagella movement, protein synthesis, and many others. Passive transport requires no cellular energy for it to occur as it moves materials across the cell membrane with the concentration gradient.
The opposite of a turgid plant cell is a
plasmolyzed plant cell. Answer Feedback:Turgid is a term that applies when a plant cell is placed in a hypotonic solution. In this type of environment, the vacuole gains water and the plasma membrane pushes against the cell wall. In a cell that is exposed to a hypertonic solution, the plasma membrane pulls away from the cell wall as the vacuole loses water.
Which of the following organelles is not surrounded by a membrane?
ribosomes Response Feedback:Ribosomes are comprised of rRNA and protein but are not bound by a membrane. They are found in both eukaryotic and prokaryotic cells.
