Cell biology - The Cell ; Cytoskeleton and cillia

Question 1

defects in keratin and collagen cause which of these conditions ?

a. progeria
b. epidermolysis bullosa

Answer 1

b.epidermolysis bullosa

Question 2

defects in nuclear lamin cause which of these conditions ?

a. progeria
b. epidermolysis bullosa

Answer 2

a.progeria

Question 3

what are the 3 types of cytoskeletal filament

Answer 3

intermediate
microtubules
actin microfilaments

Question 4

what type of filaments provide tensile strength and are made up mostly of keratin, vimentin and lamin?

a. intermediate
b. microtubules
c. actin microfilaments

Answer 4

a. intermediate

Question 5

the size of intermediate filaments lies between..

a. actin and myosin
b. microtubules and myosin
c. microtubules and actin

Answer 5

a.actin and myosin

Question 6

which filaments have a key role in tethering cells to other cells eg epithelium?

a. intermediate
b. microtubules
c. actin microfilaments

Answer 6

a. intermediate

Question 7

how do intermediate filaments strengthen epithelial cell contacts?

a. tight junctions
b. loose junctions
c. desmosomes

Answer 7

c.desmosomes

allow sheet formation and spread of mechanical stretch

Question 8

what is the second stage of IF formation/

a. monomers bind to form dimers
b. dimers bind to form staggered tetramers
c. tetramers can pack together end to end
d. IF tetramers pack together and form a helical array of 8 fibres in a ropelike formation

Answer 8

a.monomers bind to form dimers

Question 9

what type of IF is present in epithelia?

a. keratins
b. vimentin
c. neurofilaments
d. lamins

Answer 9

a.keratins

Question 10

what type of IF is present in CT?

a. keratins
b. vimentin
c. neurofilaments
d. lamins

Answer 10

b.vimentin

Question 11

what type of IF is present in nerve cells?

a. keratins
b. vimentin
c. neurofilaments
d. lamins

Answer 11

c.neurofilaments

Question 12

what type of IF is present in nucleus?

a. keratins
b. vimentin
c. neurofilaments
d. lamins

Answer 12

d.lamins

Question 13

what filaments are affected in EB

a. intermediate
b. microtubules
c. actin microfilaments

Answer 13

a.intermediate

Question 14

an autoimmunecondition in which the bodies antibodies attack the desmosomes is known as..

a,EB

b. progeria
c. pemphigus

Answer 14

c.pemphigus

Question 15

in pemphigus what do the bodys antibodies attack

a. keratin
b. nuclear lamina
c. desmosomes

Answer 15

c.desmosomes

Question 16

IFs on the nuclear lamina line which face of the nuclear envelope to provide attachment sites for DNA binding chromatin

a. outer
b. inner

Answer 16

b.inner

Question 17

what is the disassembly and reform of the nuclear lamina controlled by

a. ATP
b. phosphorylation of keratin
c. phosphorylation of lamins

Answer 17

c.phosphorylation of lamins

Question 18

when the lamina is phosphorylated it is…

a. assembled
b. disassembled

Answer 18

b.disassembled

eg dividing cells

Question 19

a mutation in nuclear lamina A leads to which condition

a,progeria

b. pemphigus
c. epidermolysis bullosa

Answer 19

a,progeria

unstable nuclear envelope lower capacity for tissue repair

Question 20

what protein are the stiff hollow tubes known as microtubules made up of

a. keratin
b. lamins
c. tubulin

Answer 20

c.tubulin

Question 21

where are microtubules anchored

a. centriole
b. centrosome
c. histones

Answer 21

b.centrosome

Question 22

what filaments are involved in cell division, anchoring organelles and intracellular transport

a. intermediate
b. microtubules
c. actin microfilaments

Answer 22

b.microtubules

Question 23

how many polar protofilaments made up of tubulin dimers combine to make up a microtubule with a positive and negative end

a,8

b. 12
c. 10
d. 13

Answer 23

d.13

Question 24

which of these filaments grow from an organising centre in the cell

a. intermediate
b. microtubules

Answer 24

b.microtubules

Question 25

y tubulin rings serve as a nucleation site for the growth of the centrosome .which end of the tubule embeds in the centrosome a. negative b. positive

Answer 25

a.negative growth occurs outwards from plus end

Question 26

which filaments grow and shrink independently (dynamic instability) a. intermediate b. microtubules c. actin microfilaments

Answer 26

b.microtubules

Question 27

what type of proteins are tubulin a. G proteins b. enzymes c. hormones

Answer 27

a.G proteins

Question 28

tubulin GTP forms which microtubule a. growing b. shrinking

Answer 28

a.growing

Question 29

what happens to the microtubule when GTP is hydrolysed on the tubulin a. grows b. shrinks

Answer 29

b.shrinks

Question 30

only GTP on which tubulin subunit is available for hydrolysis a. beta b. alpha

Answer 30

a. beta

Question 31

capping proteins at which end of the microtubule stabilise it, leading to polarisation of the cell a. negative b. positive

Answer 31

b.positive

Question 32

all transport occurs where in relation to the microtubule in neurons a,inside b.outside

Answer 32

b.outside

Question 33

what type of filaments make up cillia and flagella a. intermediate b. microtubules c. actin microfilaments

Answer 33

b.microtubules

Question 34

the 9+2 model applies to which filament a. intermediate b. microtubules c. actin microfilaments

Answer 34

b.microtubules | in cillia, 9 doublet microtubules around central pair

Question 35

what motor protein is involved in the bending of cillia

Answer 35

ciliary dynein

Question 36

what condition is autosomal recessive and leads to infertile males and increased bronchial infections a. pemphigus b. EB c. progeria d. Kartageners syndrome

Answer 36

d.Kartageners syndrome

Question 37

what filaments are targetted by cancer drugs a. intermediate b. microtubules c. actin microfilaments

Answer 37

b.microtubules

Question 38

which of these drugs blocks cell division by inhibiting microtubule assembly a. vincristine b. paclitaxel

Answer 38

a. vincristine

Question 39

which of these drugs blocks cell division by preventing microtubule shrinking a. vincristine b. paclitaxel

Answer 39

b.paclitaxel

Question 40

which fibres are involved in cell movement and shape a. intermediate b. microtubules c. actin microfilaments

Answer 40

c.actin microfilaments

Question 41

true or false actin filaments are polarised, unstable and can be stabilised by actin binding proteins a. true b. false

Answer 41

a.true

Question 42

which filaments make up the cillia a. intermediate b. microtubules c. actin microfilaments

Answer 42

c.actin microfilaments

Question 43

which filament is made up of a 2 stranded helix twist repeating every 37nm a. intermediate b. microtubules c. actin microfilaments

Answer 43

c.actin microfilaments

Question 44

actin chains grow by addition of an actin monomer carrying what a. GTP b. ATP c. ADP d. pi

Answer 44

b. ATP hydrolysing it to adp adp remains trapped until actin monomer dissociates

Question 45

polymerisation of what causes the leading end of a cell to push the cell forward a. intermediate b. microtubules c. actin microfilaments d. myosin

Answer 45

c.actin microfilaments forms a new actin cortex

Question 46

contraction by myosin 2 at which end of the cell draws the cell forward in cell crawling a. moving end b. anchored end

Answer 46

b.anchored end

Question 47

integrins are molecular hooks that allow cells to attach. what process are they involved in a. cell crawling b. microtubule building c. desmosome formation

Answer 47

a.cell crawling

Question 48

where is most of the actin found in the cell a,surrounding the nuclear envelope b. concentrated under the cell membrane

Answer 48

b. concentrated under the cell membrane

Question 49

what proteins form the cell cortex meshwork cross linking to proteins eg spectrin and ankyrin