Question 1

You disaggregate cells from two different developing organs and mix them together.Initially,they form a mixed clump.What happens next?

Accepted Answer

A) The clump stabilizes. 
B) The cells sort themselves out so that each cell adhered only to cells of the same type. 
C) The mixed clump persists. 
D) The clumped cells die. 
E) The clump forms a mesenchyme.

Question 2

Cadherins appear to be important in holding cells together in __________ tissues.

Accepted Answer

A) mesenchymal 
B) loosely cohesive 
C) tightly cohesive 
D) noncohesive 
E) gel-like

Question 3

A scientist is growing cartilage cells in culture.He accidentally spills into the culture enzymes that enzymatically digest the ECM surrounding the cartilage cells.What happens to the behavior of the cartilage cells? How could any change in behavior be reversed?

Accepted Answer

The answer of A scientist is growing cartilage cells in...

Question 4

What explains the fact that plants lack the specialized junctions seen in animal cells?

Accepted Answer

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

Question 5

Which tissues below are typically derived from the cells on the dorsal surface of a mammalian embryo after gastrulation that express N-cadherins and stop expressing E-cadherins?

Accepted Answer

A) skin 
B) only brain 
C) only spinal cord 
D) only neural tube 
E) brain,spinal cord and neural tube

Question 6

Type I collagen mutations cause a potentially lethal condition characterized by extremely fragile bones,thin skin and weak tendons.This condition is called _______.

Accepted Answer

A) osteogenesis imperfecta 
B) Ehler-Danlos syndrome 
C) Alport syndrome 
D) dwarfism and skeletal deformities 
E) diabetes

Question 7

Focal adhesions ________.

Accepted Answer

A) have been implicated in cell locomotion 
B) contain integrins that develop transient interactions with the extracellular matrix 
C) collect information about the chemical properties of the extracellular environment 
D) transmit information to the cell interior that may lead to changes in cell adhesion,proliferation or survival 
E) All of these are correct.

Question 8

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

Accepted Answer

A) desmosome 
B) desmotubule 
C) hemidesmosome 
D) annulus 
E) desmoglein

Question 9

What forms the barrier of the tight junctions that seals off the space between adjacent cells?

Accepted Answer

A) paired rows of aligned integral membrane proteins 
B) paired rows of aligned phospholipids 
C) paired rows of carbohydrates 
D) paired rows of polynucleotides 
E) interdigitating integral membrane proteins

Question 10

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

Accepted Answer

A) hemicellulose 
B) pectin 
C) amylopectin 
D) proteins 
E) desmotubulin

Question 11

Desmosomes are particularly numerous in tissues _____________.

Accepted Answer

A) that are subjected to mechanical stress 
B) like cardiac muscle 
C) like the epithelial layers of the skin 
D) like the epithelial layers of the uterine cervix 
E) All of these are correct.

Question 12

Which tight junction will form a tighter seal?

Accepted Answer

A) one with a single strand of aligned integral membrane proteins 
B) one with a number of parallel,interconnected strands of aligned integral membrane proteins 
C) tight junctions containing a special kind of phospholipid 
D) tight junctions containing a special kind of carbohydrate 
E) one with a number of parallel,interconnected strands of interdigitated integral membrane proteins

Question 13

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

Accepted Answer

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.

Question 14

Why would the collagen found in basement membranes have molecular arrangements and structure different from that found in other collagens and what are some of these differences?

Accepted Answer

The answer of Why would the collagen found in basement...

Question 15

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Accepted Answer

The answer of You are given a tissue that has...

Question 16

Which disease is an inherited blistering disease that can occur in patients with genetic alterations in any one of a number of hemidesmosomal proteins,including the $\alpha$6 or $\beta$4 integrin subunit,collagen VII or laminin-5?

Accepted Answer

A) epidermolysis bullosa 
B) bullous pemphigoid 
C) blisterosis 
D) hemidesmosomosis 
E) eczema

Question 17

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?

Accepted Answer

A) protein kinase 
B) catalase 
C) acid phosphatase 
D) succinate dehydrogenase 
E) adenylate cyclase

Question 18

Each connexon in a gap junction is constructed of ___ connexin subunits.

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 10

Question 19

Cells were allowed to bind to beads that had been covered with a coating of fibronectin.When the membrane-bound beads were pulled by an optical tweezer,the resultant mechanical stimulus was transmitted into the cell interior.What response did this cause?

Accepted Answer

A) It generated a wave of Src kinase activity. 
B) It caused nuclear shrinkage. 
C) It caused activation of phosphofructokinase. 
D) It caused inhibition of phosphofructokinase. 
E) It inhibited Src kinase activity.

Exam 7: Interactions Between Cells and Their Environment

You disaggregate cells from two different developing organs and mix them together.Initially,they form a mixed clump.What happens next?

Cadherins appear to be important in holding cells together in __________ tissues.

A scientist is growing cartilage cells in culture.He accidentally spills into the culture enzymes that enzymatically digest the ECM surrounding the cartilage cells.What happens to the behavior of the cartilage cells? How could any change in behavior be reversed?

What explains the fact that plants lack the specialized junctions seen in animal cells?

Which tissues below are typically derived from the cells on the dorsal surface of a mammalian embryo after gastrulation that express N-cadherins and stop expressing E-cadherins?

Type I collagen mutations cause a potentially lethal condition characterized by extremely fragile bones,thin skin and weak tendons.This condition is called _______.

Focal adhesions ________.

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

What forms the barrier of the tight junctions that seals off the space between adjacent cells?

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

Desmosomes are particularly numerous in tissues _____________.

Which tight junction will form a tighter seal?

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

Why would the collagen found in basement membranes have molecular arrangements and structure different from that found in other collagens and what are some of these differences?

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Which disease is an inherited blistering disease that can occur in patients with genetic alterations in any one of a number of hemidesmosomal proteins,including the $\alpha$ ₆ or $\beta$ ₄ integrin subunit,collagen VII or laminin-5?

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?

Each connexon in a gap junction is constructed of ___ connexin subunits.

Cells were allowed to bind to beads that had been covered with a coating of fibronectin.When the membrane-bound beads were pulled by an optical tweezer,the resultant mechanical stimulus was transmitted into the cell interior.What response did this cause?

Exam 7: Interactions Between Cells and Their Environment

You disaggregate cells from two different developing organs and mix them together.Initially,they form a mixed clump.What happens next?

Cadherins appear to be important in holding cells together in __________ tissues.

A scientist is growing cartilage cells in culture.He accidentally spills into the culture enzymes that enzymatically digest the ECM surrounding the cartilage cells.What happens to the behavior of the cartilage cells? How could any change in behavior be reversed?

What explains the fact that plants lack the specialized junctions seen in animal cells?

Which tissues below are typically derived from the cells on the dorsal surface of a mammalian embryo after gastrulation that express N-cadherins and stop expressing E-cadherins?

Type I collagen mutations cause a potentially lethal condition characterized by extremely fragile bones,thin skin and weak tendons.This condition is called _______.

Focal adhesions ________.

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

What forms the barrier of the tight junctions that seals off the space between adjacent cells?

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

Desmosomes are particularly numerous in tissues _____________.

Which tight junction will form a tighter seal?

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

Why would the collagen found in basement membranes have molecular arrangements and structure different from that found in other collagens and what are some of these differences?

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Which disease is an inherited blistering disease that can occur in patients with genetic alterations in any one of a number of hemidesmosomal proteins,including the α\alphaα 6 or β\betaβ 4 integrin subunit,collagen VII or laminin-5?

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?

Each connexon in a gap junction is constructed of ___ connexin subunits.

Cells were allowed to bind to beads that had been covered with a coating of fibronectin.When the membrane-bound beads were pulled by an optical tweezer,the resultant mechanical stimulus was transmitted into the cell interior.What response did this cause?

Which disease is an inherited blistering disease that can occur in patients with genetic alterations in any one of a number of hemidesmosomal proteins,including the $\alpha$ ₆ or $\beta$ ₄ integrin subunit,collagen VII or laminin-5?