Moodle multiple choice questions Flashcards
Which of the following morphological changes is NOT typically seen in a cell that is undergoing apoptosis?
Select one:
a.
The cell rounds up.
b.
The cell swells.
c.
The nuclear envelope disassembles
d.
The nuclear chromatin breaks into fragments.
e.
Large cells break up into membrane-enclosed fragments
The cell swells.
Initiator and executioner caspases share all of the following features EXCEPT that …Select one:
a.
they undergo cleavage during activation.
b.
their active form is a dimer.
c.
they are cysteine proteases (they have a cysteine residue at their active site).
d.
they are inhibited by IAPs.
e.
their inactive form is a monomer.
they are inhibited by IAPs.
Soon after the discovery of nerve growth factor (NGF), researchers injected newborn mice with rabbit antiserum (i.e. serum that contains antibodies) against NGF. They observed massive nerve cell death compared to appropriate control injections. Up to 99% of the neurons in some parts of the developing peripheral nervous system died after about a week of daily injections. These results suggest that …
developing neurons undergo cell death in the absence of NGF.
Apoptotic cells are efficiently phagocytosed by neighboring cells or macrophages. Which of the following DOES NOT normally happen in this process?Select one:
a.
The apoptotic cell loses or inactivates “don’t eat me” signals.
b.
The apoptotic cell rounds up and detaches from its neighbors, which facilitates phagocytosis.
c.
The apoptotic cell releases some of its cytoplasmic content to induce a local inflammatory response.
d.
The apoptotic cell exposes phosphatidylserine at its surface, which interacts with receptor proteins on the surface of phagocytes via “bridging” proteins.
e.
all of the above
The apoptotic cell releases some of its cytoplasmic content to induce a local inflammatory response.
Which of these is a pro-apoptotic protein
Select one:
a.
Bcl-xl
b.
Bcl-2
c.
AKT
d.
Bax
e.
IAP
Bax
Which proteins form the apoptosome?
Cytochrome c, APAF1, APAF1, Caspase 9
The extrinsic and intrinsic pathways are the only ways that apoptosis can be initiated?
True or false
False
The marker of apoptosis includeSelect one:
a.
DNA fragmentation
b.
chromatin condensation
c.
all of the above
d.
caspase activation
e.
loss of membrane integrity
all of the above
A cell in G0 is said to be in a state of,
quiescence
The G1 gap phase creates a control point to ensure a cell:
Is large enough to pass into S phase
During mitosis when does nuclear envelope breakdown occur?
Interphase
In Rao and Johnsons Cell fusion experiments, which of the following cell fusions had two mitotic nuclei in the resultant cell:
A G2 Cell fused with an M phase cell.
In Rao and Johnson’s Cell fusion experiments, which of the following cell fusions resulted in a cell with two replicating nuclei?
a G1 cell fused with an S phase cell
DNA replication and centrosome duplication occur during:
interphase
The flexibility of a biological membrane is strongly influenced by;
Temperature
Based only on the nomenclature of a fatty acid, rank these fatty acids in order of likely melting temperature, from highest to lowest.
1) 12:0
2) 10:3∆4,6,8
3) 12:1∆5
4) 12:3∆5,7,9
5) 20:0
d.
5,1,3,4,2
Which of the following amino acids are more likely to be found in the centre of a transmembrane domain of a polytopic integral membrane protein?
Leucine
In a lipid bilayer, lipids can theoretically diffuse between the membrane leaflets (termed transbilayer diffusion or “flip-flop”) or diffuse laterally in the same leaflet. Which of the following statements is TRUE?
Lateral movement of lipids is faster than transbilayer movement.
Which of the following statements is TRUE of polytopic integral membrane proteins;
1) They are held in place in the membrane by the hydrophobic effect.
2) They can either span the entire length of the hydrophobic part of the lipid bilayer or just one leaflet (one sheet of the bilayer).
3) They are usually soluble in an aqueous environment.
4) They interact with the hydrophobic core of the bilayer via predominantly non-polar amino acids.
5) They can only have one transmembrane section.
6) They are attached to the membrane by covalent attachment to a lipid headgroup.
1 and 4
