Cytoskeleton

Question 1

microfilaments

Answer 1

associated with cytokinesis (separation of two cells, creates the pinched shape)

• 7 nm
• used for cell movement
• useful for phagocytosis
• used for movement and composed of actin to form an actin polymer, which forms an actin filament
• dynamic (moves rapidly through actin polymerization and depolymerization)
• used in muscle contraction
• responsible for the amoeboid motion of macrophages

“microfilam-uscles”

Question 2

villi

Answer 2

macroscopic foldings of tissue; microvilli are foldings of the cell membrane that increase the surface area of a cell but are not responsible for movement

Question 3

cilia

Answer 3

eyelash-like structure derived from microtubules, responsible for creating motion outside of the cell. found in the trachea that move mucus around

Question 4

intermediate filaments

Answer 4

structural, permanent proteins

• static
• 10 nanometers
• the springs of the mattress
• resist mechanical stress

Question 5

macrofilaments

Answer 5

not a cellular structure (trick question!)

Question 6

microtubules

Answer 6

forms the spindle that separates homologous chromosomes

• 25 nanometers
• make up cilia (sweepers)
• flagella

Question 7

the last step of mitosis

Answer 7

cytokinesis

Question 8

cytoskeleton

Answer 8

1. structural support
2. movement
3. transport

Question 9

three major types of cytoskeleton

Answer 9

1. microtubules
2. microfilaments
3. intermediate filaments

all made of protein

Question 10

what are microtubules composed of?

Answer 10

composed of alpha tubulin and beta tubulin, joined together to form a dimer, forming a sheet called a tube, called a microtubules around 25 nm in width

anchored to the microtubule organizing center (MTOC))

Question 11

microtubule organizing centers (2 types)

Answer 11

1. centrosome

2. basal body

Question 12

centrosomes

Answer 12

made up for triplets of microtubules, 9 of which make one centriole.

27 microtubules for one centriole

the duplicate and move to opposite sides of the cell

Question 13

centromere

Answer 13

the structure at the center of the two chromosomes, surrounded by the kinetochore (an achoring site for the fibers) connected to kinetochore fibers, which turn into interpolar microtubules (see picture)