Lab 3: Cells

Of the organisms we’ll be looking at in Lab 3, which one is most closely related to animals?

 

Elodea

 

Paramecium

 

Nitella

 

Amoeba

Amoeba

The prepared slide of human cheek cells was prepared by adding methylene blue to the cells. Methylene blue binds to         [ Select ]      ["protein", "sugar", "DNA"]  and it helps to increase the         [ Select ]      ["contrast", "magnification", "resolution"]  .

DNA, contrast

The fast and long-distance movement of mitochondria along the axon of animal nerve cells is mainly facilitated by the motor proteins dynein and kinesin. Which of the following drugs are BOTH expected to reduce movement of mitochondria between the cell body and the terminal branch of an axon in animal nerve cells? 

 

FCCP (inhibits mitochondrial production of ATP) and Nocodazole (disrupts microtubules)

 

Cytochalasin D (disrupts actin filaments) and FCCP (inhibits mitochondrial production of ATP)

 

2,3-butanedione monoxime (inhibits myosin motor activity) and Cytochalasin D (disrupts actin filaments)

FCCP (inhibits mitochondrial production of ATP) and Nocodazole (disrupts microtubules)

Will beads coated in myosin be transported in an axon of a nerve cell?

 

 No, because axon transport requires a motor protein that can bind to microtubules

 

Yes, because the myosin would be able to bind to the microtubule tracks in the axon.

 

Yes, because myosin would be able to "walk" along the actin filaments in the axon

 

No because the axon does not contain ATP necessary for motor protein movement

No, because axon transport requires a motor protein that can bind to microtubules

*nerve cell = animal cell

Which of the following structures are found in plant, animal, and bacterial cells?

 

Chloroplast

 

lysosomes

 

Mitchondria

 

Ribosomes

Ribosomes

What is the direct mechanism by which FCCP inhibited cytoplasmic streaming?

 

It dissipated proton gradients, hindering ATP production

 

It binds and alters the calcium concentration of Nitella cells

 

It binds and blocks the actvity of myosin

 

It binds and alters the activity of actin.

It dissipated proton gradients, hindering ATP production

The following specimen was observed at 400x total magnification. A reticle is shown. At 100x total magnification one subdivision of the reticle represents 10um.

 

What is the approximate longitudinal (horizontal) length of the cell that is indicated by the red box? 

 

20 microns

 

200 microns

 

50 microns

 

125 microns

 

12.5 microns

125 microns

• At 100x magnification, 1 reticle subdivision = 10 μm.

• 400x magnification is 4× higher than 100x.

• Therefore, at 400x, 1 reticle subdivision = 10 μm ÷ 4 = 2.5 μm per subdivision.

• 2.5 × 50 increments = 125 microns