BIO1001 Exam 2 First Homework

Nucleic acids are not found in which of the following structures?

d) Plant vacuoles

Which of the following organelles is not enclosed in two membranes?

d) RER

Which of the following organelles is not part of the endomembrane system?

b) mitochondria

Which of the following statements about the cytoskeleton is true? a)The three cytoskeletal filaments perform distinct tasks in the cell and act completely independently of one another. b) Actin filaments and microtubules have an inherent polarity, with a plus end that grows more quickly than the minus end. c) All eukaryotic cells have actin, microtubules, and intermediate filaments in their cytoplasm. d) The cytoskeleton provides a rigid and unchangeable structure important for the shape of the cell.

Actin filaments and microtubules have an inherent polarity, with a plus end that grows more quickly than the minus end.

To observe the three-dimensional structure of a cell the best type of microscopy would be

b) scanning electron microscopy.

A bacterial cell, a plant cell, and an animal cell have which of the following structures in common?

Correct Answer Incorrect Response c) cytoplasm

The presence of _______ means that substances must pass through, rather than between, the epithelial cells that form the lining of the small intestine.

b) tight junctions

The extracellular matrix of animal cells

a) is involved in chemical signaling between cells. b) helps filter materials passing between tissues. c) contains proteoglycans. d) contains collagen.

Which of the following are processed in the Golgi apparatus? Select all that apply.

a) proteins that are secreted from the cell b) proteins that will be broken down by lysosomes d) integral membrane proteins of the plasma membrane

Staphylococcus aureus is a prokaryotic bacteria that is commonly found on human skin. When S. aureus gets into human blood stream, it can cause a serious, or even fatal, infection. Suppose you are a medical doctor treating a patient suffering from a S. aureus infection of the blood. You have variety of options in prescribing a drug, which one should you choose to save the life of your patient?

a) A drug that targets the bacterial cell wall, because human cells don't have a cell wall.

You are tutoring a second grade class at a nearby school. After you teach cell theory to these children, one of the second grades approaches you with a rock in her hand and says "I think my pet rock is alive". According to cell theory, what would be a scientifically valid response to this child?

a) A reply of "One reason that cell theory tells us the rock is not alive is that it is not made up of cells" would be valid.

The packaging of proteins to be used outside the cell occurs in the

a) Golgi apparatus.

Both the plant cells of an oak tree and the human cells of your body are eukaryotic cells. But there are some differences between the plant cells of an oak tree and the human cells in your body. Which of the following accurately describes one of those differences? a) None of the potential answers are true. b) All the human cells in your body contain a cytoskeleton, whereas not all the plant cells of an oak tree contain a cytoskeleton because the cell wall can maintain the three dimensional shape of the plant cell. c) Because all the human cells in your body are chemo-heterotrophs, they all contain mitochondria; because all the plant cells of an oak tree are photo-autotrophs, every cell of the oak tree does not contain a mitochondria. d) All of the potential answers are true. e) All the human cells in your body must maintain a balance between exocytosis and endocytosis to control plasma membrane size, but due to the central vacuole, the plant cells of an oak tree do not need to balance exocytosis and endocytosis to maintain a constant plasma membrane size

a) None of the potential answers are true.

Lysosomes are vesicles that have a very low pH. These vesicles contain enzymes that are capable of breaking down most macromolecules. What is the likely result if a single lysosome breaks open inside a cardiac cell in your heart.

a) The cardiac cell will likely not be damaged because the proteins inside the broken lysosome won't be very functional at the pH of cytoplasm.

Imagine that you are comparing the morphology of a cell that produces and secretes insulin with that of a muscle cell in your hamstring. What are some differences you might observe when looking at each of these cell types?

a) The insulin secreting cells will have more Golgi apparatus than the muscle cells of your hamstring. b) The insulin secreting cells will have less cytoskeleton components than the muscle cells of your hamstring. c) Both the insulin secreting cells and the muscle cells of your hamstring will have membrane bound receptors in their plasma membrane to respond to cellular signaling.

Which of the following statements is true? a) The nuclear membrane is thought to have arisen from the plasma membrane invaginating around the DNA. b) Lysosomes are believed to have originated from the engulfment of bacteria specialized for digestion. c) Chloroplasts and mitochondria share their DNA. d) Because bacteria do not have mitochondria, they cannot produce ATP in a membrane-dependent fashion.

a) The nuclear membrane is thought to have arisen from the plasma membrane invaginating around the DNA.

In animal cells, microtubules (which may be the most cool of all the parts of the Cytoskeleton) grow from

a) centrosomes containing centrioles.

The structure that easily distinguishes a plant cell from an animal cell is

a) chloroplasts. e) the cell wall.

Small cells function more effectively, because as cells become larger their surface area to volume ratio

a) decreases proportionally to the radius of the cell (r).

A cell biologist has developed a new drug that blocks vesicle transport at the cis face of the Golgi apparatus. What will this drug prevent from happening inside a cell?

a) the movement of the lipids and proteins from the endoplasmic reticulum to the Golgi apparatus

Bacteria are typically shaped like rods, spheres, or spirals. Bacteria are always very small, rarely larger than 1-2 μm in size, but there is some differences in size. You notice that smaller bacteria tend to be all three shapes, but larger bacteria tend to be rods or spirals. What likely accounts for the shape and size of these prokaryotes?

b) The shapes of the larger bacterial cells maximizes the surface area over which nutrients can diffuse into bacteria.

Synthesis of a protein destined to function in the nucleus occurs:

b) in the cytosol

Which of the following statements about the cytoskeleton is false?

b) Covalent bonds between protein monomers hold together cytoskeletal filaments.

Suppose that your evil roommate places the cell described by the carton into a beaker that contains a hypotonic solution of pure water! Holy Smokers!! Predict how this cell will respond.

b) Due to the fact that most charged molecules can not cross the plasma membrane, there will be little to no passive diffusion of charged molecules across the plasma membrane and out of the cell. c) Osmosis will drive water molecules into the cell through facilitated diffusion and the cell volume will increase.

The endosymbiotic model of organelle origins suggests that mitochondria and chloroplasts are the remnants of once free-living bacteria species that were engulfed by the ancestral proto-eukaryotic cell. According to the endosymbiotic model of organelle origins, which of the following must be true?

b) Mitochondria evolved before chloroplasts.

Plants are eukaryotic. Humans are eukaryotic. All eukaryotic organisms contain cells with mitochondria. Plant cells contain chloroplasts, but there are many eukaryotic organisms that do not contain any cells with chloroplasts. Which inferred statement about the endosymbiotic model may be correct?

b) Since all eukaryotic organisms contain mitochondria but not all eukaryotic organisms contain chloroplasts, mitochondria probably evolved first.

Which of the following would be synthesized in and processed by the rough endoplasmic reticulum and Golgi apparatus?

b) lysosomal enzymes

The cytoskeletal structure(s) that are composed of actin and regulate cell shape, cell movement and muscle contraction include

b) microfilaments.

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a microscope is limited by the __________ of light.

b) wavelength

Bacteria are rarely larger than 1-2 _m in size, and are typically shaped like rods, spheres, or spirals. Check all of the likely reasons for the shape and size of these prokaryotes?

c) Such shapes maximize the surface area over which nutrients can diffuse into bacteria.

Which pair of values best fills in the blanks in this statement: On average, eukaryotic cells are __________ times longer and have _________ times more volume than prokaryotic cells.

c) 10, 1000

A transmembrane protein that spans the membrane three times is synthesized by ribosomes located at the endoplasmic reticulum. Upon completion of synthesis, the C-terminus of the protein is in cytoplasm. As the protein travels through the endomembrane system, is it heavily modified in the golgi complex. Upon reaching the plasma membrane, which region of the protein is outside the cell?

c) N-terminus

You love fresh pesto so your dorm room is full of basil plants. Your evil roommate mutates all your plants and you notice that a protein normally found in the lysosome is being secreted from the cell in one of the mutants. This appears to be the only thing wrong with the mutant cells, all other proteins are targeted correctly. Based on your understanding of how proteins are secreted and the above observations, which of the following hypotheses is the most likely cause of this defect in these cells?

c) The amino acids that act as a signal sequences on the lysosomal protein are defective.

A new, photosynthetic single-celled organism was recently discovered and was classified by the team scientists who discovered it as a new species of bacteria. If the classification of bacteria is correct, select all of the following that would be true of this organism.

c) The cell's genetic material is localized to a region called the nucleoid. d) The cell has ribosomes.

Microfilaments such as actin, microtubules, and the intermediate filaments form the cell-supporting structure called the

c) cytoskeleton

The cell constantly exchanges materials by bringing nutrients in from the external environment and shuttling unwanted by-products back out. Which term describes the process by which external materials are captured inside vesicles and brought into the cell?

c) endocytosis

The organelle responsible for the biosynthesis of proteins that are destined for secretion by the cell is the

c) endoplasmic reticulum.

Integrins are glycoproteins that help link the cytoskeleton and the:

c) extracellular matrix

All cells have:

c) genetic information.

When physicians perform organ transplants, they make sure that there is a match between the donor (the person donating the organ) and the recipient (the person receiving the organ). There are many factors that go into matching the donor and the recipient. From the list below, select on that is related to things we've discussed.

c) glycyoproteins in the plasma membrane

The specialized structure that stores pigments, water, inorganic ions and maintains turgor pressure is the

c) vacuole.

Many antibiotics selectively kill bacteria and not mammalian cells because they block synthesis of the

cell wall

Some individuals with defective mitochondria in their muscles are extremely limited in their ability to exercise. Muscle biopsy, followed by microscopic examination of the mitochondria, reveal that the mitochondria are of normal size, but their inner membranes are not as convoluted as normal mitochondria. How can this mitochondrial defect cause the described symptoms in these individuals?

d) A less convoluted inner membrane has less surface area available to create the proton electrochemical gradient needed for ATP production.

Which of the following is an accurate list of all the places inside a human cell that you will find RNA.

d) Nucleus, Mitochondria, and Cytoplasm

A transmembrane protein in the outer membrane of the nuclear envelope would least likely be found later in which one of the following cellular locations?

d) a mitochondrial membrane

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?

d) cell

Photosynthesis occurs in the

d) chloroplast.

Cilia and flagella of eukaryotic cells are composed of

d) microtubules in a 9 plus 2 arrangement

organelles are able to divide and reproduce themselves like a cell those most likely to have this ability would be

d) mitochondria e) chloroplasts

Cyanide binds and impairs one of the molecules involved in the oxidative phosphorylation of ATP. The organelle that is most affected by cyanide is the

d) mitochondria.

The cellular function of the RER is

d) protein synthesis.

Large numbers of ribosomes are present in cells that produce

d) proteins.

The route that most accurately describes secretory protein movement through the endomembrane would be

d) rough endoplasmic reticulum to the Golgi apparatus to the vesicles to the plasma membrane

When a friends falls to the floor after drinking too much alcohol the organelle that will best help them to detoxify will be

d) smooth endoplasmic reticulum.

Some proteins that are on the surface of mammalian cells contain carbohydrates. These proteins are synthesized by _______ and the sugars added in the _______.

d) the rough endoplasmic reticulum; Golgi apparatus

Suppose this plant cell usually secretes the plant hormone Biggus, which increases leaf size. You treat the plant cell with a pharmaceutical compound that blocks the movement of vesicles in the cytoplasm. Which of the following describes what you would expect to observe in cells treated with the inhibitor of vesicle movement?

e) An accumulation of Biggus in the Golgi apparatus

Which of the following structures occupies the largest volume in a mature plant cell?

e) Vacuole

You are studying Kemprotein #4, a transmembrane protein that is known to function in the outer membrane of the nuclear envelope. You fuse a green fluorescent molecule to this protein to visual it in living cells. When you look at these cells under the microscope, you see the endoplasmic reticulum, Golgi apparatus, vesicles, and outer membrane of the nucleus all glowing green. What is the most accurate conclusion to draw from these observations?

e) You are visualizing all the places inside the cell that Kemprotein #4 exists.

The gonads produce steroids. The specific steroid-producing organelle in gonad cells is

e) smooth endoplasmic reticulum.

The general structural and functional differences between a nerve and smooth muscle cell within your body are a result of

e) the proteome (proteins in a cell) and the relative amounts of certain proteins that differ between muscle and nerve cells