9.1 Cilia

Question 1

What is the function of dynein in cilia?

Answer 1

Dynein anchors it’s tail to the A microtubule in cilia and produces microtubule sliding by interacting with neighboring B microtubule

Question 2

What is the function of kinesin in cilia?

Answer 2

Kinesin-dependent movement of ciliary subunits to the + ends is required for maintence of cilia.

Question 3

The study of Chlamydomonas, a motile algae was used to define this mechanism…

Answer 3

Ciliary movement.

Question 4

Outer doublet microtubule

Answer 4

Microtubule A + microtubule B (incomplete)

Question 5

Polycystic Kidney disease

Answer 5

Defect in protein called Polycystin which is a calcium channel that opens when the cilia bend in response to fluid flow. In the absence of this signal, the cells lining the tubule remain in a immature state where they reproduce rapidly and develop cysts.

Question 6

Cilia move in a _____ manner.

Answer 6

Asymmetric beating manner

Question 7

Flagella move in a _____ manner.

Answer 7

Symmetrical undulating manner.

Question 8

How does male infertility relate to cilia mutation?

Answer 8

Lack of cilia movement of sperm tail = cannot move thro the reproductive tract

Question 9

How does female infertility relate to cilia mutation?

Answer 9

Paralysis of cilia of female reproductive tract = no movement of egg or sperm

Question 10

Kartagener’s syndrome

Answer 10

Disorder affecting the movement of cilia (ex: heart on the R side of the body). Movement of cilia in the early development of life transports compounds important for development and concentrates them on one side of the body axis. When the cilia are paralyzed, the structures develop randomly.

Question 11

How are cilia anchored to the cell?

Answer 11

Anchored by a basal body with a centriole inside.

Question 12

How are the cilia microtubules nucleated?

Answer 12

From the centriole embedded in the cell outer cortex by a meshwork of actin + intermediate filaments.

Question 13

Basal body

Answer 13

Acts as a mechanical anchor for cilia where the cilia attach to the cell surface.

Question 14

Cilia centrioles

Answer 14

Short barrel-shaped arrangements of triplet microtubules. The triplet microtubules contain a complete A microtubule, and 2 incomplete B and C microtubules. A and B centriolar microtubules are continuous with A and B ciliary microtubules.

Question 15

Cilia centrioles lack ______ .

Answer 15

Central doublet microtubules

Question 16

What is the function of cilia/flagella in the respiratory tract?

Answer 16

Airway maintenance to clear debris and junk

Question 17

How are the subunits of cilia microtubules maintained over time?

Answer 17

Kinesin

Question 18

Nexin

Answer 18

The name of the protein that forms the link between the outer doublet microtubules and the inner dynein arm.

Question 19

What is the numeral organization of microtubules in mammalian cilia and flagella?

Answer 19

9 outer and 2 inner