2014/15 Flashcards
The “three domains of life” system
i) claims that all living organisms belong to three groups.
ii) groups Archaea and Bacteria in the group prokaryota.
iii) is based on a comparison of ribosomal protein sequences.
iv) is based on ribosomal RNA sequences.
v) groups plants, animals and fungi in the eukaryota.
i, iv, v
Bacterial cells have
i) a cell wall.
ii) a plasma membrane.
iii) a nucleus.
iv) mitochondria.
v) an endomembrane system.
i, ii
What is a major advantage of using green fluorescent protein in cell biology?
A. It is cheaper than any other staining method.
B. It allows the observation of protein and organelles in living cells.
C. It is less toxic.
D. It is simply a very cool tool.
E. Its use is recommended by environmental organisations.
b
Electron microscopy is suited to visualise
i) individual molecules.
ii) viruses.
iii) organelles.
iv) entire cells.
v) entire organisms.
i, ii, iii
According to the “RNA World Hypothesis”, the protocell had which of the following features?
i) It was surrounded by a lipid-bilayer (a biomembrane).
ii) It contained ribozymes and RNA.
iii) It contained several compartments.
iv) It stored information in nuclear DNA.
v) It secreted proteins into the extracellular space.
i, ii
The plasma membrane
A. surrounds mitochondria.
B. is part of the membranes of chloroplasts.
C. is another name for the endo-membrane system.
D. is the outer membrane of a cell.
E. is the system of membranes in the cytoplasm.
d
Cholesterol has which of the following functions?
i) It serves as an energy storage.
ii) It is the precursor of a vitamin.
iii) It modifies the fluidity of membranes.
iv) It is used to synthesise sex hormones.
v) None of these.
ii, iii, iv
Which structures are present in plants but are NOT found in an animal cell?
i) Cell wall.
ii) Chloroplast.
iii) Ribosome.
iv) Mitochondria.
v) Nucleus.
i, ii
A polysome
A. is a complex of many ribosomes that simultaneously translate a single mRNA.
B. is a single ribosome translating multiple mRNAs at the same time.
C. is a ribosome consisting of numerous large subunit.
D. is a ribosome complex in mitochondria.
E. is a complex of RNA-polymerase and bacterial ribosomes.
a
Protein phosphatases have the following features:
i) They remove phosphate groups from proteins.
ii) They are lipids that take part in the formation of the plasma membrane.
iii) They oppose the activity of kinases.
iv) They “walk” vesicles along the fibres of the cytoskeleton.
v) They include clathrin-receptors in the plasma membrane.
i, iii
Packaging of the DNA in metaphase chromosomes involves
A. tubulin. B. ribosomes. C. histones. D. RNA-polymerase. E. all of the above.
c
Which are the pathways that deliver material to the lysosome for degradation?
i) Autophagy
ii) Phagocytosis
iii) Secretion
iv) Endocytosis
v) Translation
i, ii, iv
Exocytosis is
A. the release of material into the extracellular space.
B. the transport of vesicles to the plasma membrane.
C. the cell wall that is surrounding plant cells.
D. a way of signalling extracellular cues to the nucleus.
E. is a crucial step in mitosis.
a
Fusion of transport vesicles with a target membrane involves
i) tethering of the vesicles to factors in the target membrane.
ii) exchange of signalling molecules between the vesicles and the membrane .
iii) docking of the vesicles to the target membrane.
iv) signalling to the nucleus.
v) recycling of the vesicles for reuse.
i, iii
Which of the following are filaments of the eukaryotic cytoskeleton?
i) Microtubules
ii) F-Actin
iii) Intermediate filaments
iv) Cellulose fibrils
v) ParM filaments
i, ii, iii
In the cytoplasm, diffusion is sufficient to distribute
i) nuclei.
ii) transport vesicles.
iii) ATP.
iv) ions.
v) organelles.
iii, iv
Microtubules have important roles in
i) lipid storage.
ii) chromosome segregation in mitosis.
iii) cell motility of ciliate protists.
iv) long-distance axonal transport.
v) generating force in cell migration.
ii, iii, iv
Primary cilia are
A. the first cilia that an embryo forms.
B. structures that mature into secondary cilia.
C. structures that take part in cellular signaling.
D. structures that are mainly composed of actin-bundles.
E. used by sperm cells to swim.
c
Which of the statements listed apply to BOTH cilia and flagella?
i) They contain an axoneme.
ii) They are formed by a basal body.
iii) They rotate due to the activity of a basal rotary motor.
iv) They show ‘intraflagellar transport’.
v) They are surrounded by the plasma membrane.
i, ii, iv, v
Hair and nails mainly consist of
A. keratin. B. kinesin. C. collagen. D. cellulose. E. microtubules.
a
Which of the following proteins are microtubule-dependent molecular motors?
A. Kinesin and myosin. B. Keratin and dynein. C. Dynein and kinesin D. Myosin and keratin E. Keratin and kinesin
c
Apoptosis is a process by which the cell
A. multiplies. B. splits in two. C. inherits its DNA. D. kills itself. E. communicates with other cells.
d
Which of the following applies to molecular motors?
i) They are enzymes that hydrolyse ATP in order to move along the cytoskeleton.
ii) They are enzymes that hydrolyse fatty acids in order to move along the cytoskeleton.
iii) They move cargo (eg membranous organelles or vesicles) through the cell.
iv) They make steps along microtubules or F-actin.
v) They utilise intermediate filaments for long-distance transport of cargo.
i, iii, iv
Cell-cell connections in animal epithelial cells serve the following functions:
i) Diffusion of ions and water between cells.
ii) Organization of the actin cytoskeleton.
iii) Limiting diffusion between cells and over the epithelium. iv) Anchoring intermediate filaments.
v) Connecting cells to the extracellular matrix.
i, ii, iii, iv, v
