chapter 19
Of the offspring that result from the reproductive cloning of mammals by somatic nuclear transfer, _______% are viable.
1-2
Humans possess about _______ different cell types.
200
Which products would result from caspase cleavage of a protein with the amino acid sequence AVEELCSTWYYDLLCHMRTL?
AVEELCSTWYYD + LLCHMRTL
An apoptosome is a complex containing multiple subunits of
Apaf-1, caspase-9, and cytochrome c
Which of the following signaling pathways is not important to stem cell physiology?
Bax
Most cells in adult animals are in the _______ stage of the cell cycle.
G0
Which of the following diseases would not be an ideal target for therapeutic cloning?
HIV
Which of the following is not phosphorylated by Akt?
PI 3-kinase
A major pathway that signals cell survival and inhibits cell death is the _______ pathway.
PI 3-kinase/Akt
Which of the following are the three core transcription factors that can reprogram adult somatic cells into induced pluripotent cells?
Sox2, Oct4, and Nanog
The PI 3-kinase pathway is important in countering apoptosis in healthy cells and promotes cell survival. Which statement about the PI 3-kinase pathway is false?
activated Akt phosphorylates and activates Bad
Hematopoietic stem cells can give rise to
all blood cells and macrophages
A hematopoietic stem cell may give rise to which of the following differentiated cells?
all of the above
Bone marrow transplants are used to treat patients with
all of the above
Effector caspases cleave
all of the above
Which of the following adult cell types is arrested in G 0?
all of the above
TNF and related cytokines can directly induce apoptosis. Which statement about TNF-mediated induction of apoptosis is true?
all of the above statements are true
The distinct series of changes that characterizes programmed cell death is called
apoptosis
Intestinal epithelial stem cells are located _______ the crypt.
at the bottom of
Which of the following transcription factors has the potential to act as an oncogene, resulting in a high risk of cancer?
c-Myc
The gene ced-3 of C. elegans codes for a proteolytic enzyme that is a
caspase
Which of the following events is not associated with apoptosis?
cell cycle re-entry
VEGF is secreted by
cells deprived of oxygen
Many stimuli that trigger cell death release the molecule _______ from the intermembrane space of mitochondria so they can bind to Apaf-1.
cytochrome c
Which of the following is not a key property of stem cells in tissues?
dividing within each tissue to maintain a set number of cells
Members of the Bcl-2 family of proteins are
either antiapoptotic or proapoptotic
Which of the following stem cells can give rise to all the differentiated cell types of adult organisms?
embryonic stem cells
Each of the three cell types in the adult intestinal epithelium is derived from a different stem cell.
false
Injured muscle cells regenerate by division of muscle fibers to form myoblasts that proliferate and fuse to form new muscle fibers.
false
Liver cell injury induces proliferation of liver stem cells.
false
Apoptotic cells produce "eat me" signals, which include _______ of cell surface _______.
gain; phosphatidylserines
Using approaches similar to those of Takahashi and Yamanaka, scientists have now reprogrammed adult fibroblasts to become
heart muscle cells
Ced-9 functions directly to
inhibit Ced-4
Cells that die as the result of acute injury undergo
lysis
Which of the following events is not part of apoptosis?
lysis of cell fragments and release of their contents
During development, 50% of neurons die; those that survive are those that
made correct connections with their target cells
In 2006, Takahashi and Yamanaka demonstrated that somatic cells can be reprogrammed or converted into induced pluripotent stem cells. Subsequent studies in _______ showed that these cells, like embryonic stem cells, are capable of differentiating into virtually all cells.
mice
Some differentiated cells retain the ability to proliferate as needed to repair damaged tissue throughout the life of the organism. Which of the following cell types do not retain this unique ability?
neurons
Bax and Bak act by
oligomerizing in the mitochondrial outer membrane, forming pores that release cytochrome c
The following represents a signal transduction cascade initiated by double-stranded DNA damage and ending with activation of apoptosis by the BH3-only proteins PUMA and Noxa. Double-stranded DNA damage; Chk2; _______; PUMA/Noxa; apoptosis. Which protein belongs in the blank?
p53
The key protein involved in "deciding" whether a cell with DNA damage should delay its cell cycle or undergo apoptosis is
p53
In adult organisms, cell death must be balanced by cell
renewal
The stem cells of skeletal muscle are called
satellite cells
Which statement about stem cells is false?
stem cells in organs can only differentiate into the tissue in which they are located
Which statement about cloning by somatic cell nuclear transfer is false?
the cloned embryo is genetically identical to the foster mother
Mammalian embryonic stem cells are cultured from cells taken from
the inner cell mass
What is the best rationale for the use of therapeutic cloning to replace defective cells or tissues in a patient?
the transplanted cells are identical to those of the recipient who donated the adult nucleus, so complications of immune rejection are avoided
Which statement about caspases is false?
they predominantly break up Golgi membranes, which releases other capsases to cleave nuclear lamins and cytoskeleton proteins
Early experiments by Takahashi and Yamanaka showed that a set of four genes introduced by retroviral expression are capable of transforming somatic cells into induced pluripotent stem cells. The four proteins encoded by these genes were all
transcription factors
The reprogramming of somatic cells into other types of differentiated cells (other than induced pluripotent stem cells) is referred to as
transdifferentiation
Intestinal stem cells may give rise to all of the following terminally differentiated cell types in the intestinal epithelium except _______ cells.
transit-amplifying
When stem cells of the intestinal epithelium and epidermis divide, they give rise to two different cells: one stem cell and one _______ cell.
transit-amplifying
A mutant bcl-2 gene can be an oncogene.
true
As a causal factor in the development of tumors, the inability of cancer cells to undergo apoptosis is as significant as their uncontrolled proliferation.
true
Goblet cells and enteroendocrine cells have the same stem cells as absorptive epithelial cells.
true
If reintroduced into early embryos, embryonic stem cells can give rise to cells in all tissues of a mouse.
true
In normal, nonapoptotic cells, antiapoptotic members of the Bcl-2 protein family bind to proapoptotic members and inhibit their activity.
true
It is relatively easy to isolate and propagate embryonic stem cells.
true
Most differentiated cell types do not themselves proliferate, but they can be replaced by the proliferation of stem cells.
true
Programmed cell death plays an important role in development.
true
Reproductive cloning of humans raises ethical concerns.
true
Satellite cells are located beneath the basal lamina of muscle fibers.
true
The clinical application of adult stem cells is limited by difficulties in isolating and culturing the appropriate stem cell populations.
true
Which of the following is not considered a viable source of stem cells?
tumor cell