Laboratory Assignment: Virtual Microscopy

1. On the UD Virtual Compound Microscope, examine the onion root tip slide at 400X viewing magnification. Ensure that the image is centred. What is the approximate size of an onion root tip cell? Show your work and specify which dimension of the cell (length or width) you are using. (2 marks)

RESPONSE: The dimension of the cell I am using is length. The number of specimen is 11.
The Field of view would be 0.35 mm because we are looking at the onion root tip at 400X magnification.

Actual size= FOV diameter/ # of specimen that can fit across FOV Actual size= 0.35mm/11 specimen= 0.032mm
The actual size of the onion root tip is 0.032mm
PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

2. Now examine the onion root tip cells at 1000X viewing magnification.

What is the size of an onion cell at this magnification? Show your work, and use the same dimension that you did in the previous question. (2 marks)

RESPONSE: The dimension of the onion root tip is length.

Get quality help now

RhizMan

Verified writer

Proficient in: Onion

4.9 (247)

“ Rhizman is absolutely amazing at what he does . I highly recommend him if you need an assignment done ”

+84 relevant experts are online

Hire writer

The field of view is 0.14mm because we are looking at the onion root tip at 1000X magnification.
Actual size= FOV diameter/ #of specimens that fit across FOV Actual size= 0.14mm/5 specimen= 0.028mm
The actual size of the onion root tip is 0.028mm
PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

3. Does the actual size of the cell really change from 400X to 1000X viewing
magnification? If your answers to the two previous questions were different, how do you account for the difference? (1 mark)

RESPONSE: No the actual size doesn’t really change from 400X to 1000X viewing magnification.
My two answers in the previous questions were different but that could be accounted for the fact that were estimating the amount of species there are in your FOV and for one person could see one amount and another person could see another amount base on what they believe is enough of the specimen showing in the FOV.

PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

4. What is the approximate diameter of a cheek cell nucleus? Show your work, including a formula and units. (2 marks)
RESPONSE: The dimension that I am using for cheek cell nucleus is width. The magnification I used is 100X, The FOV would then be 1.38mm because I

have a magnification of 100X and the number of specimen in the FOV is 6. Actual size= FOV diameter/ # of specimen that fit across FOV Actual size= 1.38mm/6 specimen= 0.23mm
The approximate diameter of a check cell nucleus is 0.23mm.
PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

5. What is the approximate size of one of the bacterial cells, including the capsule? This will be more difficult, but you should be able to make a rough (but reasonable) estimate. Show your work, including a formula and units. (2 marks)

RESPONSE: I used the 4X magnification. The bacteria including the capsule was able to fit in the lens 1.25 times, so approximately 0.63 of the cell fits in the lens. Field of view would be 3.5mm because I used 4X magnification Actual size= FOV diameter/ # of specimen that fir across FOV Actual size= 3.5mm/ 0.63= 5.56mm

The approximate size of one bacterial cell including the capsule is 5.56mm.

PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

Image Magnification and Scale Bars

The questions below refer to the images on the ‘Image Magnification and Scale Bars’ page of the Virtual Microscopy Lab.
6. Samples of three types of organisms (A, B, and C) were collected from a pond. They are shown as they would appear under a light microscope, with the objective magnifications used to view them as indicated. In this particular ecosystem, organisms must be at least 2.5 times bigger, as measured by the longest dimension, than a potential prey item in order to be able to consume it for food. Are any of these organisms a potential prey item for any of the others? If so, which one(s)? Support your answer with calculations; be sure to include the correct units. (2.5 marks) RESPONSE: Organism A: Has an objective magnification of 4X making the field of view for this organism 3.5 mm.

The number of specimen that fit in the FOV is 7 and the dimension I’m using is width.
Actual size= FOV diameter/ #of specimen that can fit in FOV
Actual size= 3.5mm/7= 0.5 mm
The approximate size of Organism A is 0.5.mm
Organism B: Has and objective magnification of 100X making the field of view for this organism 0.14mm.
The number of specimen that fit in the FOV is 1 and the dimension I am using is length.
Actual size= 0.14mm/1=0.14mm
The approximate size of Organism B is 0.14mm.
Organism C: Has an objective magnification of 10X making the field of view 1.38mm.
The number of specimen that can fit in the FOV is 2 and I’m using the dimension width.
Actual size=1.38mm/2= 0.69mm
The approximate size of Organism C is 0.69mm.
Organism C and Organism B could prey on organism A but Organism C could not prey on organism B.

PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

7. Image D represents a sketch of Organism C from the pond water sample. The box around it represents a piece of 8.5 in x 11in (21.6 cm x 27.9 cm) paper. Calculate a distance to be represented by the scale bar; show all of your work, including the correct units. (3 marks)

RESPONSE:
Actual size of scale bar/ size of image= size represented by scale bar/ actual size of the specimen
When I was measuring the paper for Organism C is13.4cm for the actual size. The actual size for the longest part of the paper is 28cm and the size of organism C when measured is 2.3cm.
2.3cm/13.4cm=X/28cm
0.172cm=X/28cm
X=4.80cm
To find the scale bar:
1.2/13.4cm(28cm)=X
X=0.251cm
0.251cm x 10cm=25.1cm
X=25.1mm/48.0mm(0.55)
X= 0.288mm is the actual size of the scale bar.
PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

Interpreting Micrographs
The questions below refer to the images on the Interpreting Micrographs page of the Virtual Microscopy Lab.
8. Micrograph A shows the phospholipid bilayer of a plasma membrane. Estimate the width of the bilayer, and explain how you did so. (1 mark) RESPONSE: Using equations and method in question 7 I would have to say that the phospholipid bilayer would be 0.67 microns.

PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

9. Micrograph B shows two cells of the same type treated with fluorescent stains. Assuming that the outer perimeter of the image where the stain ends is in fact the outer boundary of the cells themselves, what type of cells do you think these are - plant, animal, or bacterial? How did you rule out the other two options? (1 mark)

RESPONSE: I believe that these two cells are animal cells because one bacterial cells are prokaryotic and not eukaryotic which means that it does not contain a nucleus so that takes bacterial out of the picture. It also wouldn’t be a plant cell because plant cells have rigid cell walls causing little movement where in this picture it shows where the cell membrane isn’t a specific shape meaning the cell has movement leaving it to be an animal cell.

PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

10. What type of cell – plant, animal, or bacterial – do you think is pictured in the centre of Micrograph C? What do you think the circular structures are? Do you see anything wrong with Micrograph C? (1.5 marks) RESPONSE: I think the type of cell that is in micrograph c is a bacterial cell because it has no nucleus around it and the cells surrounding it (spherical ones) are also bacterial cells because they also do not contain a nucleus. What is pictured in the center of micrograph C looks to be a bacillus bacteria. The circular structures looks to be coccus bacteria.

Whats wrong with this micrograph is that bacillus and coccus bacteria surround themselves with more coccus and bacillus bacteria and don’t mix together. PLEASE LEAVE THE SPACE BELOW EMPTY FOR TA COMMENTS

Lab Assignments Survey Questions
We’re interested in your feedback! Please visit the Lab Assignments Survey, via the ‘Proctor and Other Surveys’ page in the Course Menu of the class
site, to enter your responses to the questions below. This survey is anonymous. 1. Approximately how long did it take you to complete this assignment?