Question 1

Which are NOT one of the ways that cells connect to each other?
A) Gap junction
B) Adherens junction
C) Desmosome
D) Zonula occludens
E) Connectosome

Accepted Answer

Connectosome is not a recognized term for a cellular junction. Gap junctions, adherens junctions, desmosomes, and zonula occludens (tight junctions) are all established types of cell junctions that facilitate various forms of cell-to-cell adhesion and communication.

Question 2

Of the following, the organelle most involved in the synthesis of lipids is the
A) Rough endoplasmic reticulum
B) Smooth endoplasmic reticulum
C) Golgi apparatus
D) Peroxisome
E) Endosome

Accepted Answer

The smooth endoplasmic reticulum (SER) is primarily involved in the synthesis of lipids, including phospholipids and steroids. It lacks ribosomes, which distinguishes it from the rough endoplasmic reticulum (RER) that is involved in protein synthesis.

Question 3

Kinesin and dynein move vesicles and other cargo along tracts composed of
A) Myosin
B) Desmin
C) Actin
D) Tubulin
E) Intermediate filaments

Accepted Answer

Kinesin and dynein are motor proteins that move along microtubules, which are composed of tubulin, to transport vesicles and other cargo within cells.

Question 4

Double membranes are part of the structure of
A) The endoplasmic reticulum
B) The mitochondria
C) The peroxisome
D) The Golgi apparaturs
E) The cytoskeleton

Accepted Answer

Mitochondria have a double membrane structure, consisting of an outer membrane and an inner membrane, which is key to their function in energy production through cellular respiration.

Question 5

The boundary between the inside and outside of a cell is provided by the
A) Cell membrane
B) Endoplasmic reticulum mem brane
C) Mitochondrial membrane
D) Nuclear Envelope
E) Cytoskeleton

Accepted Answer

The cell membrane, also known as the plasma membrane, is the structure that encloses the cell, separating its interior from the external environment and thus serving as the boundary between the inside and outside of a cell.

Question 6

Gap junctions are formed by
A) Integrins
B) Cadherins
C) Desmoplakin
D) Connexin
E) Plakophilin

Accepted Answer

Gap junctions are formed by connexin proteins, which assemble into hexameric structures called connexons to facilitate intercellular communication.

Question 7

The concentration of solutes in the cytoplasm of most cells follows which of the following order, from grea test to least:
A) Na>K>ATP>Ca
B) K>Na>ATP>Ca
C) Na>K>Ca>ATP
D) Na>ATP>K>Ca
E) ATP>Na>K>Ca

Accepted Answer

The concentration of solutes in the cytoplasm of most cells is highest for potassium (K), followed by sodium (Na), then ATP, and finally calcium (Ca). This reflects the typical intracellular environment, where potassium ions are more abundant inside cells, while sodium ions are more prevalent outside. ATP and calcium ions are present in lower concentrations within the cell.

Question 8

W hich of the following supports the endosymbiotic hypothesis
A) Mitochondria contain circular DNA separate from nuclear DNA
B) Mitochondria consume oxygen
C) Lysosomes contain hydrolytic enzymes
D) Mitochondria import proteins from the cytoplasm
E) Ribosomes contain RNA

Accepted Answer

The endosymbiotic hypothesis suggests that mitochondria originated from free-living prokaryotes that were engulfed by a host cell. The presence of circular DNA in mitochondria, similar to bacterial DNA, supports this hypothesis.

Question 9

Cells adhere to each other through all of the following junctions EXCEPT
A) Desmosomes
B) Gap junctions
C) Zonula adherens
D) Zonula occludens
E) Zonula cadhera

Accepted Answer

Zonula cadhera is not a type of cell junction.

Question 10

The Svedberg is defined as A) kT /D B) 6$\pi$ $ \eta $ a C) $ \omega $²r/g D) (dr/dt) / $\omega$²r E) -$\beta$ v

Accepted Answer

The Svedberg unit (S) is a measure of the rate of sedimentation during centrifugation. It is defined as the sedimentation coefficient, which is the rate of sedimentation (dr/dt) divided by the centrifugal force ($\omega$²r).

Question 11

The relative centrifugal force is given as A) kT /D B) 6$\pi$ $ \eta $ a C) $ \omega $²r/g D) (dr/dt) / $\omega$²r E) -$\beta$ v

Accepted Answer

The relative centrifugal force (RCF) is often expressed in terms of the angular velocity ($\omega$) and the radius (r) from the center of rotation, with g representing the acceleration due to gravity. The formula $ \omega^2r/g $ correctly represents the calculation for RCF, making option C the correct choice.

Question 12

Most of the oxygen consumption of human cells occurs in the
A) Cytosol
B) Peroxisomes
C) Lysosomes
D) Nucleus
E) Mitochondria

Accepted Answer

Most of the oxygen consumption of human cells occurs in the mitochondria, where oxygen is used in the process of oxidative phosphorylation to generate ATP, the cell's main energy currency.

Question 13

Purified subcellular organelles are most often isolated by
A) Electron microscopy
B) Differential centrifugation
C) Free zone electrophoresis
D) Light microscopy
E) Bouyant density centrifugation

Accepted Answer

Differential centrifugation is a technique used to separate subcellular organelles based on their size and density. It involves spinning a cell homogenate at different speeds to pellet organelles of different sizes.

Question 14

Of the following, the organelle most involved with packaging and processing of secreted proteins is the
A) Endoplasmic reticulum
B) Peroxisome
C) Golgi apparatus
D) Nucleus
E) Mitochondria

Accepted Answer

The Golgi apparatus is primarily responsible for modifying, sorting, and packaging proteins for secretion. It acts as a processing center where proteins received from the endoplasmic reticulum are further processed and then directed to their destination.

Question 15

Proteasomes degrade proteins that are "tagged" by
A) Myristoylation
B) Palmitoylation
C) Formation of disulfide bonds
D) Farnesylation
E) Ubiquitinylation

Accepted Answer

Proteasomes degrade proteins that are tagged by ubiquitinylation. This process involves attaching ubiquitin molecules to a protein, marking it for degradation by the proteasome.

Question 16

Intermediate filaments differ from the other cytoskeletal filaments in that
A)Intermediate filaments have a polarity (+ and - ends)
B) Intermediate filaments are dynamic along their entire length, not just the ends
C) They are approximately 100 nm in diameter
D) Intermediate filaments are polymers of globular monomeric proteins
E) Intermediate filaments do not differ from the other cytoskeletal elements except in size

Accepted Answer

Intermediate filaments differ from microfilaments and microtubules, which have polarity and are dynamic mainly at their ends. Intermediate filaments, however, provide structural stability and are not polarized or dynamic in the same way.

Question 17

The endosymbiotic hypothesis proposes that
A) Lysosomes fuse with endocytotic vesicles to form secondary lysosomes
B) Phagocytosis was a precursor to the gastrointestinal system
C) Secondary active transport is necessary for life
D) Mitochondria originated from engulfment of aerobic bacteria
E) The nucleus was once a separate cell

Accepted Answer

The endosymbiotic hypothesis specifically suggests that mitochondria (and also chloroplasts in plants) originated from the engulfment of aerobic bacteria by a precursor to modern eukaryotic cells, leading to a symbiotic relationship.

Question 18

All of the following organelles of the cell have mem branes that enclose a space except
A) Mitochondria
B) Peroxisomes
C) Cytoskeleton
D) Lysosomes
E) Nucleus

Accepted Answer

The cytoskeleton is a network of fibers that provides structural support to the cell, not an organelle enclosed by a membrane. Mitochondria, peroxisomes, lysosomes, and the nucleus all have membranes.

Quiz 6: Cell Structure

Which are NOT one of the ways that cells connect to each other?

Of the following, the organelle most involved in the synthesis of lipids is the

Kinesin and dynein move vesicles and other cargo along tracts composed of

Double membranes are part of the structure of

The boundary between the inside and outside of a cell is provided by the

Gap junctions are formed by

The concentration of solutes in the cytoplasm of most cells follows which of the following order, from grea test to least:

W hich of the following supports the endosymbiotic hypothesis

Cells adhere to each other through all of the following junctions EXCEPT

The Svedberg is defined as

The relative centrifugal force is given as

Most of the oxygen consumption of human cells occurs in the

Purified subcellular organelles are most often isolated by

Of the following, the organelle most involved with packaging and processing of secreted proteins is the

Proteasomes degrade proteins that are "tagged" by

Intermediate filaments differ from the other cytoskeletal filaments in that

The endosymbiotic hypothesis proposes that

All of the following organelles of the cell have mem branes that enclose a space except