Bio/Ensci 251 Ch. 4 Practice Problems

The organelles and biomolecules present in homogenized cells can be separated by centrifugation. Which of the following would be found at the top of a centrifugation gradient? a) Golgi b) Mitochondria c) Nuclei d) Ribosomes e) ATP molecules

- ATP molecules

The proteins tha tmake up the cytoskeleton of bacteria are similar ...... in eukaryotic cells. a) proteases b) sterols c) actin d) transcription factors e) telomerases

- Actin

Prokaryotes... a) are surrounded by a cell membrane b) have a nucleus c) do not have ribosomes d) have a cell wall similar in composition to that of plant cells e) are larger than eukaryotic cells

- Are surrounded by a cell membrane

Which organelles are involved in energy conversions? a) Lysosomes b) Vacuoles c) Chloroplasts d) Peroxisomes e) Nuclei

- Chloroplasts

The extracellular matrix of animal cells... a) is not involved in chemical signaling between cells b) aids in blocking materials from passing between tissues c) contains proteoglycans d) contains cellulose e) pigments the cells

- Contains proteoglycans

Which statement about the nucleus of animal cells is true? a) It occupies the smallest volume of the cell b) It powers the cell c) It is enclosed by a single membrane d) DNA in the nucleus combines with proteins e) The nucleus is the site of protein synthesis

- DNA in the nucleus combines with proteins

DNA strands are visualized using a(n)... a) light microscope b) electron microscope c) dissecting microscope d) centrifuge e) thermocycler

- Electron microscope

One of the following, the ....., which is enclosed in a membrane, has the greatest amount of internal surface area. a) nucleus b) endoplasmic reticulum c) mitochondrion d) chloroplast e) ribosome

- Endoplasmic reticulum

Besides the proteins being processed for distribution, what other components could be expected to be found inside the Golgi apparatus? a) Ribosomes b) Enzymes c) DNA d) Cytoskeleton

- Enzymes

Which organelle(s) is/are found only in plants? a) Glyoxysomes b) Golgi c) Peroxisomes d) Mitochondria e) Endoplasmic reticulum

- Glyoxysomes

Which is an advantage of eukaryotic cell structure over prokaryotic cell structure? a) Different cell functions are compartmentalized and kept separate from one another in membrane-bound organelles in eukaryotic cells. b) Eukaryotic cell size is large, which allows for rapid transport of materials within the interior of the cell c) Eukaryotic cells have a nucleus, which allows them to replicate their genetic information to pass on to daughter cells during cell division. d) Having so many membranous compartments enables eukaryotic cells to be impervious to the surrounding environment.

- Having so many membranous compartments enable eukaryotic cells to be impervious to the surrounding environment.

Liver cells are exposed to radioactive amino acids, making all proteins synthesized during this time radioactive. The cells are then removed at 5-minute intervals and fractionated. Where in the cells is the radioactively-labeled enzyme lipase performing its intracellular functions? a) In the endoplasmic reticulum b) In the Golgi apparatus c) In lysosomes d) On ribosomes e) In the cytoskeleton

- In lysosomes

The endomembrane system... a) is present in prokaryotes b) includes the endoplasmic reticulum and the mitochondria c) includes the Golgi apparatus and the endoplasmic reticulum d) functions to make ATP e) does not exist in plant cells

- Includes the Golgi apparatus and the endoplasmic reticulum

Which protein(s) power(s) the movement of both cilia and vesicles within a cell? a) Myosin b) Actin c) Keratin d) Dynein only e) Kinesin and dynein

- Kinesin and dynein

Which structure(s) is/are directly involved in the movement of organelles within a cell? a) Golgi apparatus b) Endoplasmic reticulum c) Mitochondrion d) Microtubules e) Intermediate filaments

- Microtubules

In a multicellular organism, different cells are specialized for certain functions to help the whole organism maintain the living state. As cells differentiate to become specialized, the abundance of different organelles shifts to best serve those needs. Which organelle might be expected to be present in high abundance in a mammal's muscle cells that must extract large amounts of energy from food molecules to support the work of muscle contraction? a) Vacuole b) Golgi apparatus c) Mitochondrion d) Peroxisome

- Mitochondrion

Cilia and eukaryotic flagella... a) propel cells by rotation of structures b) contain microfilaments c) contain microtubules that are sufficient to drive movement d) must have a motor protein that uses the energy of ATP hydrolysis to power movement e) contain centrioles

- Must have a motor protein that uses the energy of ATP hydrolysis to power movement

Which structure is known for its lack of nucleic acids? a) The nucleus b) Mitochondrion c) Plant vacuole d) Ribosome e) Prokaryotic cell

- Plant vacuole

What happens to proteins as they pass through the Golgi apparatus? a) Proteins are degraded into smaller polypeptide chains b) Proteins are modified by having sugars attached or removed c) Proteins are unfolded and refolded into new conformations d) Proteins are assembled into large multi-protein complexes

- Proteins are modified by having sugars attached or removed

Amoeba proteus is injected with a drug that inhibits the formation of microtubules. What effect will this have on the organism's movement? a) It will survive, but it will not be able to move b) It will show hyperactive movement c) It will die, and thus will not move d) It will only be able to move in one direction e) The drug will have no effect on the organism's movement

- The drug will have no effect on the organism's movement

A student discussing the role of the Golgi apparatus in cells makes the following three statements: A variety of proteins enter the Golgi from vesicles that pinch off from the rough ER. Within the Golgi apparatus, different proteins are modified by the activities of sugar molecules. After modification, the proteins move within vesicles to specific locations in the cell. Evaluate the accuracy of the student's statements. a) Each is an accurate statement b) Only the first statement is accurate c) The first and third statements are accurate; the second statement is not accurate d) The second and third statements are accurate; the first statement is not accurate

- The first and third statements are accurate; the second statement is not accurate

Some proteins that are on the surface of mammalian cells contain carbohydrates. These proteins are synthesized by _______ and the carbohydrates are added in the _______. a) mitochondrial ribosomes; smooth endoplasmic reticulum b) the rough endoplasmic reticulum; Golgi apparatus c) Cytoplasmic ribosomes; smooth endoplasmic reticulum d) Golgi apparatus; rough endoplasmic reticulum e) cytoplasmic ribosomes; cell membrane

- The rough endoplasmic reticulum; Golgi apparatus

The presence of _______ means that substances must pass through, rather than between, the epithelial cells that form the lining of the small intestine. a) gap junctions b) tight junctions c) desmosomes d) plasmodesmata e) microtubules

- Tight junctions

Which structure occupies the largest volume in a mature plant cell? a) Peroxisome b) Ribosome c) Chloroplast d) Vacuole e) Mitochondria

- Vacuole

The correct order of movement of proteins through the Golgi apparatus is... a) medial, cis, trans b) cis, trans, medial c) trans, medial, cis d) cis, medial, trans

- cis, medial, trans

Plastids are... a) present in nearly all plants cells b) always green c) present in photosynthetic prokaryotes d) present in all eukaryotes e) very similar to mitochondria

- present in nearly all plant cells