exam 2 bio

Question 1

Membrane phospholipids?

Answer 1

may have​ ʺkinksʺ in their​ tails, each caused by the presence of a double bond between carbons.

Question 2

One difference between eukaryotic and prokaryotic cells is that eukaryotic cells

Answer 2

have​ membrane-enclosed organelles, which are lacking in prokaryotic cells.

Question 3

Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular​ component?

Answer 3

DNA —> RNA —–>protein

Question 4

Which of the following choices correctly matches a tool and its proper​ application?

Answer 4

cell fractionation to study the function of specific organelles

Question 5

Which of the following microscopy techniques is best suited for visualizing protein complexes in their cellular environments without the use of​ preservatives?

Answer 5

Cryo-electron microscopy

Question 6

Which of the following clues would tell you if a cell is prokaryotic or​ eukaryotic?

Answer 6

whether or not the cell is generally partitioned by internal membranes

Question 7

Which of the following correctly matches an organelle with its​ function?

Answer 7

central vacuole with storage

Question 8

Which structure is common to plant and animal​ cells?

Answer 8

Mitochondrion

Question 9

Which of the following statements best describes one major difference between prokaryotic cells and eukaryotic​ cells?

Answer 9

Eukaryotic cells have​ membrane-bound organelles, while prokaryotic cells do not.

Question 10

Which of the following structures is common to plant and animal​ cells?

Answer 10

mitochondrion

Question 11

Which of the following areas in bacterial cells best describes where chromosomal DNA is generally​ localized?

Answer 11

In the nucleoid

Question 12

Which of the following parameters is most likely to limit the maximum size of a​ cell?

Answer 12

The ratio of surface area to volume of cytoplasm

Question 13

Select the correct statement describing cellular structure or function.

Answer 13

Plant and animal cells both carry out cellular​ respiration, producing ATP.

Question 14

Beginning within the​ nucleus, the first step leading to the synthesis of a polypeptide is​ _____.

Answer 14

Transferring of information from DNA to messenger RNA

Question 15

Which molecules do not normally cross the nuclear​ membrane?

Answer 15

DNA

Question 16

Which of the following statements about the nuclear envelope is false​?

Answer 16

The nuclear envelope is continuous with the Golgi apparatus.

Question 17

True or​ false? Large proteins containing a nuclear localization signal​ (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy.

Answer 17

False

Question 18

A small protein​ (molecular weight​ = 25,000​ daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken​ place?

Answer 18

Passive transport

Question 19

In experiments to test whether a protein can enter the​ nucleus, why would proteins be labeled with fluorescent​ molecules?

Answer 19

To make the proteins easy to see

Question 20

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?

Answer 20

Only one of the two fusion proteins possesses a nuclear localization signal.

Question 21

SCIENTIFIC INQUIRY
Imagine protein​ X, destined to span the plasma​ membrane; assume ​the mRNA carrying the genetic message for protein X has been translated by ribosomes in a cell culture. If you fractionate the​ cells, in which fraction would you find protein​ X?

Answer 21

Pellet rich in “microsomes”

Question 22

Which of the following statements best describes the function of the nuclear pore complex found in eukaryotic​ cells?

Answer 22

It regulates the movement of proteins and RNAs into and out of the nucleus.

Question 23

Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules out of the​ nucleus?

Answer 23

mRNA

Question 24

Which organelle plays a role in intracellular​ digestion?

Answer 24

lysosome

Question 25

Which one of the following statements about the endomembrane system is​ correct?

Answer 25

Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system.

Question 26

Which structure is part of the endomembrane system?

Answer 26

Golgi apparatus

Question 27

Which cell would be best for studying​ lysosomes?

Answer 27

Phagocytic white blood cell

Question 28

Which of the following organelles often occupy the majority of the volume of a plant​ cell?

Answer 28

Central vacuole

Question 29

Which of the following organelles is primarily responsible for the production and modification of polysaccharides that will be​ secreted?

Answer 29

Golgi apparatus

Question 30

A cell with a predominance of rough endoplasmic reticulum is most likely involved in which of the following​ processes?

Answer 30

Producing large quantities of proteins for secretion

Question 31

A cell with a predominance of smooth endoplasmic reticulum is most likely specialized to carry out which of the following​ processes?

Answer 31

Synthesis of large quantities of lipids

Question 32

Tay-Sachs disease is a human genetic disorder that results in cellular accumulation of very​ large, complex, undigested lipids. Which of the following organelles is most likely defective in​ Tay-Sachs disease?

Answer 32

The lysosome

Question 33

A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed​ below?

Answer 33

Rough ER → Golgi → transport vesicle → plasma membrane

Question 34

Asbestos is a material that was extensively used in construction for decades. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by​ phagocytosis, but are not able to degrade it. Toxicity most likely results from accumulation of asbestos in which of the following​ organelles?

Answer 34

Lysosomes

Question 35

Which of the following is a common trait of chloroplasts and​ mitochondria?

Answer 35

Both contain their own DNA

Question 36

Gaucher disease is the most common genetic disorder affecting lipid storage in humans. The disease is caused by deficiency of an enzyme necessary for the breakdown of​ lipids, which leads to the accumulation of fatty material in organs of the body including the​ spleen, liver,​ kidneys, lungs,​ brain, and bone marrow. Which of the following statements provides the most plausible explanation for how organelles are impacted by Gaucher disease. The rough endoplasmic reticulum most likely contains excess​ ribosomes, which results in overproduction of the enzyme involved in lipid breakdown.

Answer 36

The lysosomes most likely lack sufficient amounts of the enzymes necessary for lipid breakdown.

Question 37

Which of the following structures is independent of the endomembrane system in eukaryotic​ cells?

Answer 37

chloroplast

Question 38

Peroxisomes in liver cells detoxify alcohol by removing hydrogen atoms and combining them with which of the following​ molecules?

Answer 38

With oxygen molecules to generate hydrogen peroxide

Question 39

An early step in the evolution of eukaryotic cells most likely involved which of the following​ events?

Answer 39

Endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell—the endosymbiont evolved into mitochondria.

Question 40

While abundant quantities of proteins are produced by free ribosomes in the​ cytosol, new proteins are also produced by which of the following​ organelles?

Answer 40

Mitochondria

Question 41

The cilia and flagella of eukaryotic cells are composed of​ _____. intermediate filaments

Answer 41

Microtubules

Question 42

Which of the following functions is NOT associated with the cytoskeleton in eukaryotic​ cells?

Answer 42

Movement of RNA molecules from the nucleus to the cytoplasm

Question 43

Motor proteins provide for molecular motion in cells by interacting with which of the following cellular​ structures?

Answer 43

Components of the cytoskeleton

Question 44

Which of the following molecules is required by cells to assemble cilia or​ flagella?

Answer 44

Tubulin

Question 45

Researchers investigating the mechanism of vesicle transport assembled a​ cell-free system that included​ microtubules, vesicles, and ATP.​ However, they observed no movement of transport of vesicles because the mixture was missing which of the following​ components?

Answer 45

Motor proteins

Question 46

Which of these cell junctions form a barrier to the passage of​ materials?

Answer 46

Tight junctions

Question 47

The primary role of​ _____ is to bind animal cells together

Answer 47

Desmosomes

Question 47

_____ aid in the coordination of the activities of adjacent animal cells.

Answer 47

Gap (communicating) junctions

Question 48

Choose the fundamental characteristics of life.

Answer 48

-To reproduce and pass along characteristics to offspring -To transform energy -To respond to the environment

Question 48

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell​ walls?

Answer 48

Plasmodesmata

Question 49

How does a cell display the fundamental characteristics of​ life?

Answer 49

It is possible because all the functions performed by the individual structures and organelles of a cell are integrated.

Question 50

Why does the phenomenon called​ "life" appear only at the level of the cell and not at the level of an organelle or an even smaller​ level?

Answer 50

Not one of the cellular components could exist indefinitely on its own. Organelles should interact with each other to function properly.