Question 1

Which of the following proteins are known to be associated with focal adhesions? (Select all correct choices)
A)actin
B)aconitase
C)myosin
D)malin

Accepted Answer

Actin and myosin are known to be associated with focal adhesions. Aconitase and malin are not typically associated with focal adhesions.

Question 2

Which of the following tissues are typically derived from mesenchymal cells? (Select all correct choices)
A)mesodermal tissues
B)ectodermal tissues
C)blood
D)muscle

Accepted Answer

Mesenchymal cells are multipotent stromal cells that can differentiate into a variety of cell types, including those that form mesodermal tissues, blood, and muscle. Ectodermal tissues are not derived from mesenchymal cells.

Question 3

The green algae which first grew in a terrestrial environment are called ______________
A)cyanobacteria
B)charophycean green algae
C)filamentous green algae
D)bryozoans

Accepted Answer

Charophycean green algae are the closest living relatives of land plants and were the first green algae to evolve in a terrestrial environment. Cyanobacteria are not green algae and did not evolve in a terrestrial environment. Filamentous green algae and bryozoans also did not necessarily evolve in a terrestrial environment.

Question 4

Which of the following is NOT a function of the plant cell wall?
A)It allows plant cells to develop osmotic turgor pressure that pushes against their surrounding walls.
B)It provides mechanical support for individual cells and serves as a type of "skeleton" for the whole plant.
C)It protects cells against damage from mechanical abrasion, osmotic influx of water & pathogens.
D)It prevents cell-cell interactions.
E)It can be a source of signals that alter activities of cells that it contacts.

Accepted Answer

The plant cell wall is involved in many functions such as providing mechanical support, protecting against damage, and allowing for osmotic turgor pressure. However, it does not prevent cell-cell interactions, as it has pores and channels that allow for communication and transport of molecules between adjacent cells.

Question 5

What structure accounts for the fact that plants lack the specialized junctions seen in animal cells?
A)the presence of the large central vacuole
B)the presence of chloroplasts
C)the presence of the cell wall
D)the presence of mitochondria
E)the absence of centrioles, basal bodies, cilia and flagellae

Accepted Answer

The cell wall provides structural support and protection to the plant cell, and does not allow for the formation of specialized junctions between cells, such as gap junctions or tight junctions, that are seen in animal cells. The other options (A, B, D, E) do not directly relate to the lack of specialized junctions in plant cells.

Question 6

From what cell organelle does the desmotubule appear to be derived?
A)Smooth endoplasmic reticulum of the two cells
B)Rough endoplasmic reticulum of the two cells
C)Golgi apparatus of the two cells
D)secretory vesicles of the two cells
E)cell wall of both cells

Accepted Answer

The desmotubule is derived from the smooth endoplasmic reticulum of the two cells. It is a structure that extends through the plasmodesmata, connecting the cytoplasm of adjacent cells and facilitating intercellular communication.

Question 7

What type of protein also seen in animal cells spans the plant plasma membrane and is thought to transmit signals from the cell wall to the cytoplasm?
A)protein kinase
B)catalase
C)acid phosphatase
D)succinate dehydrogenase
E)adenylate cyclase

Accepted Answer

Protein kinases are enzymes that modify other proteins by chemically adding phosphate groups to them (phosphorylation). This process is crucial for signal transduction, allowing the transmission of signals from the cell wall to the cytoplasm, and is a mechanism seen in both plant and animal cells.

Question 8

The dense central structure that is derived from the smooth endoplasmic reticulum and usually seen in the plasmodesmata is called a(n)________.
A)desmosome
B)desmotubule
C)hemidesmosome
D)annulus
E)desmoglein

Accepted Answer

The dense central structure seen in plasmodesmata is called a desmotubule, which is derived from the smooth endoplasmic reticulum. Choices A, C, D, and E are all structures found in animal cells and do not relate to plasmodesmata.

Question 9

What changes in the central region of the dorsal surface of the single-celled epithelial layer of a chick embryo lead to the formation of the primitive nervous system? (Select all correct responses)
A)a reduction in the expression of E-cadherin genes
B)a reduction in the expression of N-cadherin genes
C)an elevation in the expression of N-cadherin genes
D)an elevation in the expression of E-cadherin genes

Accepted Answer

A reduction in the expression of E-cadherin genes and an elevation in the expression of N-cadherin genes are key changes in the central region of the dorsal surface of the single-celled epithelial layer of a chick embryo that lead to the formation of the primitive nervous system. This process involves a switch in cadherin types, which is crucial for the cells in this region to change their adhesion properties and behaviors, facilitating the formation of the neural tube, the precursor to the nervous system.

Question 10

The filaments associated with hemidesmosomes are correctly known as __________. (Select all correct choices)
A)actin filaments
B)keratin filaments
C)microtubules
D)intermediate filaments

Accepted Answer

Hemidesmosomes are associated with keratin filaments, which are a type of intermediate filament.

Question 11

Cell walls of young, undifferentiated plant cells grow along with the cells of which they are a part and thus exhibit extensibility. What are they known as?
A)primary walls
B)secondary walls
C)expandophiles
D)complete walls
E)incomplete walls

Accepted Answer

Young, undifferentiated plant cells have primary walls that exhibit extensibility and grow along with the cells they are a part of.

Question 12

The thicker walls seen in mature plants that no longer allow extensive growth of the cell wall are known as _______.
A)primary walls
B)secondary walls
C)complete walls
D)incomplete walls

Accepted Answer

Secondary walls are thicker walls that are deposited inside the primary walls of mature plant cells. These walls provide additional support and strength to the plant and do not allow for extensive growth of the cell wall.

Question 13

The enzyme embedded in the plant cell membrane that catalyzes the growth of a cellulose molecule is called _________.
A)cellulase
B)cellulose synthase
C)Rubisco
D)PEP carboxylase
E)cellulose transferase

Accepted Answer

Cellulose synthase is embedded in the plant cell membrane and catalyzes the growth of a cellulose molecule by linking glucose monomers together. The other enzyme choices listed are not involved in cellulose synthesis.

Question 14

Patients that have died of L1-deficiency disease are missing a nerve tract that ________. (Select all that apply)
A)runs between the brain and the spinal cord
B)runs between the two halves of the brain
C)runs between the spinal cord and cerebellum
D)runs between the brain and the endocrine system

Accepted Answer

The L1-deficiency disease is a rare genetic disorder that affects the development of the nervous system. Patients with this disease are missing a nerve tract that runs between the brain and the spinal cord (A) and a nerve tract that runs between the two halves of the brain (B).

Question 15

How is the structure of the mature plant cell wall similar to the structure of the corneal stroma of the chicken embryo?
A)Both contain cellulose.
B)Both contain adjacent layers of fibers that run parallel to each other.
C)Both contain phospholipids.
D)Both contain adjacent layers of fibers that are arranged perpendicular to each other.
E)Both are composed of collagen.

Accepted Answer

The mature plant cell wall and corneal stroma of the chicken embryo both contain adjacent layers of fibers that are arranged perpendicular to each other. The plant cell wall is composed of cellulose and other polysaccharides, while the corneal stroma is composed of collagen and proteoglycans. Therefore, options A, C, and E are incorrect. Option B is not accurate because the fibers in the plant cell wall are typically not parallel.

Question 16

What lines the plasmodesmata seen in plant cells?
A)integral membrane proteins
B)peripheral proteins
C)carbohydrates
D)plasma membrane
E)DNA

Accepted Answer

The plasmodesmata are structures that connect adjacent plant cells and are lined by the plasma membrane.

Question 17

You are studying a plant and inject fluorescein, a fluorescent dye, into a single cell on the surface of the plant. After a brief period of time, the dye spreads to cells neighboring the injected cell. What do you conclude?
A)The cells are connected by the cell wall.
B)The cells are connected by tight junctions.
C)The cells are connected by gap junctions.
D)The cells are connected by plasmodesmata.
E)The cells are connected by zonulae adherens.

Accepted Answer

Plasmodesmata are channels that connect adjacent plant cells through their cell walls. This allows for movement of materials such as fluorescein between cells. Tight junctions and gap junctions are found in animal cells, not in plant cells. Zonulae adherens are a type of anchoring junction found in animal cells, not in plant cells.

Question 18

What class of plant cell proteins facilitates plant cell growth by causing a localized relaxation of the cell wall, which allows the cell to elongate at that site in response to turgor pressure generated within the cell?
A)extensins
B)desmins
C)expansins
D)protein kinases
E)phosphatases

Accepted Answer

Expansins are plant cell proteins that facilitate plant cell growth by causing a localized relaxation of the cell wall, which allows the cell to elongate at that site in response to turgor pressure generated within the cell. Extensins are structural proteins found in plant cell walls, while desmins are intermediate filament proteins found in animal cells. Protein kinases and phosphatases are involved in signaling and regulation of cellular processes, but not specifically in cell wall relaxation and elongation.

Question 19

Which of the following is typified by an epithelial-mesenchymal transition or EMT? (Select all correct choices)
A)formation of the mesoderm during gastrulation in a chick or mammalian embryo
B)cells breaking away from a cohesive epiblast
C)fusion of sperm and egg
D)formation of cartilage

Accepted Answer

An epithelial-mesenchymal transition or EMT is a process in which epithelial cells lose their cell-cell adhesion and apical-basal polarity to acquire a mesenchymal, migratory phenotype. This process is involved in various physiological and pathological events, such as the formation of the mesoderm during gastrulation in a chick or mammalian embryo, and cells breaking away from a cohesive epiblast. Fusion of sperm and egg or formation of cartilage does not involve EMT.

Question 20

Which plant cell wall molecule is economically important as a component essential for the production of jams and jellies?
A)hemicellulose
B)pectin
C)amylopectin
D)proteins
E)desmotubulin

Accepted Answer

Pectin is a polysaccharide found in the cell walls of fruits and vegetables. It is an important component in the production of jams, jellies, and other fruit products as it acts as a gelling agent.

Quiz 7: Interactions Between Cells and Their Environment

Which of the following proteins are known to be associated with focal adhesions? (Select all correct choices)

Which of the following tissues are typically derived from mesenchymal cells? (Select all correct choices)

The green algae which first grew in a terrestrial environment are called ______________

Which of the following is NOT a function of the plant cell wall?

What structure accounts for the fact that plants lack the specialized junctions seen in animal cells?

From what cell organelle does the desmotubule appear to be derived?

What type of protein also seen in animal cells spans the plant plasma membrane and is thought to transmit signals from the cell wall to the cytoplasm?

The dense central structure that is derived from the smooth endoplasmic reticulum and usually seen in the plasmodesmata is called a(n) ________.

What changes in the central region of the dorsal surface of the single-celled epithelial layer of a chick embryo lead to the formation of the primitive nervous system? (Select all correct responses)

The filaments associated with hemidesmosomes are correctly known as __________. (Select all correct choices)

Cell walls of young, undifferentiated plant cells grow along with the cells of which they are a part and thus exhibit extensibility. What are they known as?

The thicker walls seen in mature plants that no longer allow extensive growth of the cell wall are known as _______.

The enzyme embedded in the plant cell membrane that catalyzes the growth of a cellulose molecule is called _________.

Patients that have died of L1-deficiency disease are missing a nerve tract that ________. (Select all that apply)

How is the structure of the mature plant cell wall similar to the structure of the corneal stroma of the chicken embryo?

What lines the plasmodesmata seen in plant cells?

You are studying a plant and inject fluorescein, a fluorescent dye, into a single cell on the surface of the plant. After a brief period of time, the dye spreads to cells neighboring the injected cell. What do you conclude?

What class of plant cell proteins facilitates plant cell growth by causing a localized relaxation of the cell wall, which allows the cell to elongate at that site in response to turgor pressure generated within the cell?

Which of the following is typified by an epithelial-mesenchymal transition or EMT? (Select all correct choices)

Which plant cell wall molecule is economically important as a component essential for the production of jams and jellies?