Supportive tissues, such as bone or wood, derive their strength from:
extracellular matrix.
The driving force for plant cell growth is:
turgor pressure.
What gives the plant cell wall its tensile strength?
Cellulose
A plant cell elongates in which direction?
Perpendicular to the orientation of the cellulose microfibrils
Which of the following determines the direction that cellulose is laid down in the extracellular space of a plant cell?
The orientation of microtubules on the cytoplasmic side of the plasma membrane
Which of the following tissues is characterized by a plentiful extracellular matrix?
Connective
In connective tissues, the tensile strength of the tissue is chiefly provided by:
collagen
Fibroblasts are found in which tissues?
Connective
Cells export collagen to the extracellular matrix as:
procollagen (a single-stranded collagen polypeptide chain with additional peptides at each end).
Fibroblasts play a role in:
orienting collagen.
A fibroblast can attach indirectly to collagen via which type of protein?
Fibronectin
Which protein in a fibroblast's plasma membrane attaches to the extracellular matrix on the outside of the cell and (through adapter molecules) to actin inside the cell?
Integrin
Which of the following is NOT true of integrin?
Integrin molecules are always activated and serve as stable anchor with two sticky ends.
In the extracellular matrix of animal tissues, which of the following molecules allows the matrix to resist compression?
Proteoglycans
Which feature of glycosaminoglycans allows the extracellular matrix in cartilage to resist compression?
The negative charges on glycosaminoglycans attract sodium ions, which in turn draw a large amount of water into the extracellular matrix.
True or False:
Cells joined together in epithelial sheets line all external and internal surfaces of the animal body.
TRUE
Which of the following is NOT true of the basal lamina?
The basal lamina lines the inside of epithelia cells at the basal membrane surface.
Which epithelial cell junctions serve to seal neighboring cells together so that water-soluble molecules cannot easily leak between them?
Tight junctions
Which of the following epithelial cell junctions is not involved in providing mechanical strength to an epithelial sheet?
Gap junctions
Cadherin proteins:
link epithelial cells together by binding to similar cadherins in adjacent epithelial cells.
Which type of epithelial junction plays a role in an epithelial sheet's ability to develop tension or change its shape by contraction?
Adherens junction
In desmosomes, cadherin molecules are anchored inside an epithelial cell to which type of cytoskeletal filament?
Intermediate filaments
Epithelial cells are attached to the basal lamina by:
hemidesmosomes.
Which of the following is NOT true of gap junctions?
They allow ATP-driven pumps to move substances from one cell to another.
Which of the following is the plant equivalent of a gap junction?
Plasmodesmata
True or False:
A tissue is made of a single type of cell bound together by extracellular matrix.
FALSE
True or False:
All tissues are renewed at the same rate.
FALSE
In a tissue, which of the following cell types divides to create a continuous supply of differentiated cells?
Stem cells
True or False:
Every stem cell gives rise to single type of progeny cell.
FALSE
In the intestine, Wnt proteins:
promote the proliferation of the stem cells at the base of each intestinal crypt.
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Which of the following cell types, under appropriate conditions, can be kept proliferating indefinitely in culture and yet retain unrestricted developmental potential?
Embryonic stem cells
A major problem with using cells grown in culture in human transplants is that:
the host immune system may attack the cells.
Therapeutic cloning is used to:
generate embryonic stem cells.
TRUE OR FALSE:
Using just 3 genes, scientists can transform adult cells into cells that behave like embryonic stem cells.
TRUE
What is the difference between a malignant and benign tumor?
A malignant tumor invades and colonizes other tissues, while a benign tumor does not.
True or False:
Most cases of cervical cancer are caused by a viral infection.
TRUE
Which of the following is responsible for the most cancer cases?
Tobacco smoke
Cancer is fundamentally which type of disease?
A genetic disease
How many mutations are required for a normal cell to turn into a cancer cell?
More than 3
Which of the following can give rise to cancer causing mutations?
#NAME?
Which of the following is NOT a key behavior of cancer cells?
They digest neighboring cells to fuel proliferation.
A single mutation can activate which class of cancer causing gene?
Oncogene
Two mutations are needed to inactivate which class of cancer causing gene?
Tumor suppressor gene
TRUE OR FALSE:
Proto-oncogenes play an important role in controlling the division of normal cells.
TRUE
Many of the genes mutated in individual tumors fall under which of the following regulatory pathways?
#NAME?
TRUE OR FALSE:
Having one normal copy and one mutated copy of the APC is enough to cause colorectal cancer.
FALSE
Some cancer cells are missing a key protein needed to repair double-strand DNA breaks, and survive by relying on alternative DNA repair mechanisms. To treat these cancers, researchers have developed drugs that:
Inhibit alternative DNA repair mechanisms.