BIOLOGY 103
FALL, 2003
LAB 3

From Organisms to Cells: Size Relations
(Generating and Testing Hypotheses)


Name:  Paul Grobstein
Username:  pgrobste@brynmawr.edu
Subject:  lab 3
Date:  2003-09-23 12:38:18
Message Id:  6585
Comments:
As you've discovered, scientific research can be done (and often is done) with vague general questions that in turn motivate making observations that in turn lead to more specific understandings and new questions and hypotheses.

Scientific research can also be done by using general questions and existing observations to shape an hypothesis that itself motivates new observations. Today's lab is aimed at giving you some experience with the latter kind of scientific research.

We know that multicellular organisms come in a variety of sizes but that they all have in common that they are assemblies of cells. A general question that follows from this is "is there any relation between the size of an organism and the size of the cells that make it up?".

Your task today (in groups of two) begins with thinking of some possible general answers to this question, and about which ones make good (ie interesting and testable) hypotheses. You should then pick such an hypothesis and (using tools we will make available, including a microscope) collect relevant observations.

Your report should include a brief description of your hypothesis and of what motivated it, an account of your observations, and a conclusion in which you discuss the significance of your observations for your hypothesis.


Name:  
Username:  Anonymous
Subject:  Natalya Krimgold and Nancy Evans
Date:  2003-09-23 14:50:25
Message Id:  6587
Comments:
The researchers hypothesized that larger organisms are not necessarily composed of larger cells than smaller organisms. This hypothesis was based on the premise that many organism are composed of specialized cells that perform different functions and those cells may vary in size. The examination of four cell specimens from organisms of varied sizes supported the researchers' hypothesis. The four cell specimens and their measurements were as follows:
1. Elodia, 104 X 26 um
2. Cheek, 52 um in diameter
3. Larynx, 20.8 X 5.2 um
4. Corn Root 26 um to 52 um in diameter
The Elodia cell is much larger than the cheek or larynx cells although the Elodia plant is much smaller than a human being. In addition cell size within an organism can vary substantial as the corn root cells did which also indicates that cell size does not vary directly with organism size. The exact relationship between cell size and organism size remains to be determined.
Name:  Maria Scott-Wittenborn, Michel
Username:  hchoi@brynmawr.edu
Subject:  does size really matter?
Date:  2003-09-23 15:00:02
Message Id:  6588
Comments:
Maria Scott-Wittenborn, Michelle HoKyung Choi

Hypothesis:
If two organisms (regardless of their size) belong to the same species, then their cell sizes will be similar.

Motivation of Hypothesis:
Common sense told us that all cells are not the same size. For example, an ostrich egg is one complete cell while an amoeba is also one complete cell but of significantly smaller size. But within the same species if size differs, then the quantity of cells may differ but the size of the cells which actually make up the organism does not differ.

Observations:
(Human)
5'7" --> 10x = 7 um/OR
5'5" ---> 10x = 7 um/OR

(Maple leaf)
4" --> 10x = 2 um/OR
1.5" --> 10x = 2 um/OR

(Clover leaf)
1/2" --> 10x = 1.5 um/OR
1/4" --> 10x = 1.5 um/OR

(Mushroom)
3/4" --> 10x = 3 um/OR
1/2" --> 10x = 3 um/OR

Conclusions:
From the small sample of organisms we investigated we have concluded that our hypothesis is correct; as long as the specimens are within the same species their cell sizes are the same. However, within our sample of organisms cell sizes proved to differ between species relevant to the organisms' size (i.e. Humans over 5' tall, 7 um; clover leaves smaller than 1", 1.5 um).


Name:  Brianna Twofoot, Brittany Plad
Username:  Anonymous
Subject:  Bio Lab
Date:  2003-09-23 15:02:20
Message Id:  6589
Comments:
Group: Brianna Twofoot, Brittany Pladek


Problem: Does the size of cells depend, relatively, on the size of the overall organism?

Hypothesis: Cells occur in a size range which varies according to the size of the multicellular organism. For example, human cells will be bigger than moss cells.

Observations (in microns)
Algae: 4060
Cheek cell: 3050
Trachea cell: type 1: 12
Type 2: 37
Worm epidermis: ~ 350
Moss globule: 3050
Moss strand: ~10

These observations indicate that cells do not occur in a size-relative relationship. For example, while the earthworm as a whole organism is smaller than a human, the human cheek cells are smaller than the earthworm epidermis cells. However, we must keep in mind that we only sampled a specific type of cell for each organism. There are many different types of cells. For example, of the two moss cell-types sampled, one type was 10 microns in length while one was 3050 microns. We must modify our hypothesis to say that not only do cells not vary in size relative to their greater organism, but cells within a certain-sized organism come in many different shapes and sizes, each different, none relative to the overall size of the organism.


Name:  see subject
Username:  kottati@brynmawr.edu
Subject:  LaToiya, Katie
Date:  2003-09-23 15:05:09
Message Id:  6590
Comments:
We started out with the hypothesis that cell size does not have direct correlation to the size of the organism. We based this on the knowledge that organisms are composed of different kinds of cells that vary in size, shape and function. What if a human spinal cord cell is larger than an algae cell, but a human cheek cell is smaller?

Data:
Algae:
- cell #1: 26 um (@ 4x)
- cell#2: 72 um (@4x)

Human Cheek:
- cell #1: 5.2 um (@40x)
- cell #2: 5.85um (@40x)

Human Spinal Cord:
- cell #1: 1.82 um (@40x)
- cell#2: 2.6 um (@40x)

Earthworm:
-cell#1: 13 um (@40x)
- cell#2: 14.3 um (@40x)

Based on our observations it seems that our hypothesis may not be correct. From the size of the cells measured, it appears that smaller organisms have larger cells, which means that from the size of the cells you can estimate the size of the organism. Perhaps smaller organisms have fewer, larger cells than larger organisms, which have many small cells. In other words, "size does matter".


Name:  
Username:  Anonymous
Subject:  Abby, Melissa, Talia
Date:  2003-09-23 15:05:21
Message Id:  6591
Comments:
Hypothesis:
There is an inverse relationship between the size of the organism and the size of the cell -- as an organism gets larger, the cells become smaller.
Our reasoning for this hypothesis was that a larger organism requires more complex functions necessary for survival. Therefore, we thought that smaller cells, and therefore more cells, would allow for these more complex systems to survive.
From our observations of various samples from organisms of various sizes, we found that our hypothesis was not consistent with the numbers that we collected. First we organized the organisms according to size - largest to smallest: human samples (spinal cord and cheek cells, earthworm, buttercup, paramecium). Then, after collecting our data, we converted all the numbers to one common system and ordered the cells from largest to smallest: cheek cell, buttercup, earthworm, spinal cord, paramecium.
We disproved our hypothesis! yay!
According to our findings, which may be flawed because of our lack of experience in measuring cells, it would seem that the size of the organism and the size of the cells do not follow a set pattern.
Question to consider: would it be more helpful if we could measure the surface area of a cell because of the variance in cell shapes?
Name:  
Username:  Anonymous
Subject:  Su-Lyn & Sarah
Date:  2003-09-23 15:05:51
Message Id:  6592
Comments:

Hypothesis:
The size of the cell is not correlated to the size of the organism. In considering what "relevant samples" to look at, we realized that even within the same organism, there would be different types of cells of different shapes and sizes. This led us to consider the difference between multicellular organisms and single-cell organisms. In the latter case, we imagine that the cell would expand in size as the organism grows. However, the growth of multicellular organisms could affect the size of their cells differently. While these cells could expand as well, we think that an organism would grow primarily by multiplying the number of cells in it. Furthermore, with the higher number of cells, there would most likely be specialization, with different types of cells taking on different functions. Because of this specialization, we could expect cells in multicellular organisms to be smaller and more plentiful.

Our hypothesis, therefore, is that the size of the cell is not correlated to the size of the organism.

Account of observations
Organism (size in micrometers)
Moss (20.8x31.2 and 9.1x23.4)
Corn root (40x60 and 50x40 and 70x60)
Artery (36.4x26)
Blood cells (3x5)
Muscles (not measurable too big)
Cerebellum (5.2x7.8, while some not measurable too small)
Earthworm (65x5.2)

Conclusion:
We feel that the observations refute any direct correlation between the size of the organism and the size of the cells that make it up. Cells clearly exist in many different types and sizes even within the same sample. In the cerebellum sample, we were able to obtain measurements on one type of cell, but not on another. The research supports our initial hypothesis but more money will be required to study a wider range of samples in terms of organisms and cell types.


Name:  Manuela Ceballos and Laura Wol
Username:  Anonymous
Subject:  Manuela Ceballos and Laura Wolfe
Date:  2003-09-23 15:06:23
Message Id:  6593
Comments:
Our hypothesis states that we would find larger cells when looking at larger organisms under a microscope. Our observations were:

Larynx cell = 18.2 micro meters

Spinal cord cell = 13 micro meters

Moss cell = 150 micro meters (50 micro meters in width)

Earth worm cell = 39 micro meters

Buttercup cell = 48.2 micro meters


Based on these observations, our original hypothesis was proven wrong. For instance, an earth worm is generally smaller than a human, however its cells were found to be larger. In addition, in each sample we found cells multiple sizes, colors and shapes - the measurements were taken from the clearest areas of vision. This leads us to a more important point - different organisms have different kinds of cells, (in humans, for example, the larynx cells differed significantly from the spinal cord cells). We can suggest, from our observations, that the link between size of an organism and the size of its cells is more arbitrary than we orginally hypothesized. Perhaps if we compared corresponding cells in organisms, such as a human spinal cord cell to a dog's spinal cord cell, we might get closer to finding a relationship concerning size. However, these correspondences are not often present, because plants have no spinal cords, for instance, so we would be required to find a different method of comparison.


Name:  Charlotte Haimes, Elisabeth Py
Username:  chaimes@brynmawr.edu
Subject:  Cell size
Date:  2003-09-23 15:06:30
Message Id:  6594
Comments:
Elisabeth Py, Charlotte Haimes

hypothesis: The greater the size of an organism, the greater the size of its cells.

Observations:
- Humans:
cheek cell: average size = 70 microns
vein cell: average size = 46.8 microns
spinal cord cell = 57.2 microns

- Elodea:
between 19 and 27 hash marks (X40)
average cell size = 241.8 microns

- Wild Algae
between 14 and 19 hash marks (X40)
average cell size = 174.2 microns

Conclusion:
There is no absolute relation between the size of an organism and the size of the cells that constitute it. As we observed earlier, the elodea's average cell size is larger than that of the human's. We also observed that cells within one organism are approximately the same size.


Name:  Paula & Romina
Username:  parboled@brynmawr.edu
Subject:  Lab3
Date:  2003-09-23 15:07:10
Message Id:  6595
Comments:
Group Members--Paula Arboleda, Romina Gomez


Hypothesis: The smaller the organism, the smaller the cell. We felt that the most obvious way of trying to make relationships between these different organisms is to begin by making size/cell comparisons.

Observations:

Romina's cheek cell:
4x--104 mm/or
10x--70 mm/or
40X--65 mm/or
Description: Small, oval

Paula's cheek cell:
4x--100 mm/or
10x--60 mm/or
40x--59.8 mm/or

Algea 1
4x--650 mm/or
10x--600 mm/or
40x--26 mm/or (26 was the measurable unit because it extended beyond the measurement capacity of the ruler)
Description: Long, rectangular, green

Algea 2
4x--104 mm/or
10x--150 mm/or
40x--130 mm/or
Description: Small, brownish

Buttercup Mature Root
4x--52 mm/or
10x--6 mm/or
40x--57.2 mm/or
Description: Small, circular

Flowering Plant
4x--104 mm/or
10x--100 mm/or
40x--130 mm/or
Description: Long, thin, rectangular

Conclusions:

Well, our observations have led us to believe that the size of the organism and the size of the cells are independent of each other. For example, we noticed that the buttercup mature root had almost the same size as that of a human cheek cell. We, therefore, cannot say with any certainty that this presumed relationship exists.


Name:  justine & shafiqah
Username:  Anonymous
Subject:  
Date:  2003-09-23 15:07:56
Message Id:  6596
Comments:
Shafiqah Berry and Justine Patrick
Hypothesis: Does the complexity of an organism dictate the variety and the complexity of a cell?
Experiment:
In our experiment we examined several different types of specimens ranging from plant life to human cheek cells and animal cells. We found that for the plant cells the structure seemed to be very rigid and geometrically shaped. For example in the elodea cell there were elongated strips of cells. The rigid block like structure of the cell components in the middle of the cell indicated the fact that this cell structure made up the cell wall. The simplicity of the cell as demonstrated by the cell patterns indicate the incomplexity of the organism which is a plant. When we viewed the spinal cord or the trachea cells we found much more "diversity" in the cellular structure. Litlle clumps and big sections of cells, it was grreat!! There was an absence of a single pattern. The cheek unlike the other human cells was only a single cell that contained a nucleus. This however does not exclude it from the human cell category because its shape was different from the shape of a plant cell. The fact that there was no cell wall lead us to the conclusion that the cheek cell was human. Other non plant cells included the worm cross-section slide. We viewed that there were concentric circles of cells. The center was larger than the outer rings, think Saturn! not el coche, no the planet.
In conclusion; aka grand finale- we have new questions such as ; what would happen if a dna gene of a human being was spliced with a cellular wall? what was our hypothesis again? it doesn't matter at this stage. we feel that it does have some correlation to biology.
Name:  Maria Scott-Wittenborn, Michel
Username:  hchoi@brynmawr.edu
Subject:  does size really matter?
Date:  2003-09-24 13:28:53
Message Id:  6606
Comments:
Maria Scott-Wittenborn, Michelle HoKyung Choi

Hypothesis:
If two organisms (regardless of their size) belong to the same species, then their cell sizes will be similar.

Motivation of Hypothesis:
Common sense told us that all cells are not the same size. For example, an ostrich egg is one complete cell while an amoeba is also one complete cell but of significantly smaller size. But within the same species if size differs, then the quantity of cells may differ but the size of the cells which actually make up the organism does not differ.

Observations:
(Human)
5'7" --> 10x = 7 um/OR
5'5" ---> 10x = 7 um/OR

(Maple leaf)
4" --> 10x = 2 um/OR
1.5" --> 10x = 2 um/OR

(Clover leaf)
1/2" --> 10x = 1.5 um/OR
1/4" --> 10x = 1.5 um/OR

(Mushroom)
3/4" --> 10x = 3 um/OR
1/2" --> 10x = 3 um/OR

Conclusions:
From the small sample of organisms we investigated we have concluded that our hypothesis is correct; as long as the specimens are within the same species their cell sizes are the same. However, within our sample of organisms cell sizes proved to differ between species relevant to the organisms' size (i.e. Humans over 5' tall, 7 um; clover leaves smaller than 1", 1.5 um).


Name:  megan williams & maggie tucker
Username:  mswillia@brynmawr.edu
Subject:  lab 3
Date:  2003-09-24 14:37:50
Message Id:  6607
Comments:
Hypothesis- Cells that come from similar species will carry similar traits and sizes. Size alone of the matter from which the cell came from will not affect the size of the single cell.

Our data-
Buttercup- measured at 40x, 23or= 53.8 um
Corn- measured at 40x, 22or= 51.2 um
Moss- measured at 10x, 15or = 150 um (length)
Larynx- measured at 40x, 50or = 130 um (length)
Human Cheek- measured at 40x, 30or = 78 um

Our observations lead us to the conclusion that size of an organism is not the deciding factor in cell size. We noticed also that while some of the plant samples (buttercup and corn) were close in cellular size, the moss was much larger. So we can also derive that similar species do not necessarily have similar cell size. A question we have from our observations is, is the complexity of the cellular make up of an organism a factor in similarity in cell size?


Name:  
Username:  Anonymous
Subject:  cells cells cells
Date:  2003-09-24 14:47:17
Message Id:  6608
Comments:
Enor Wagner and Katy McMahon
Lab #3
September 24. 2003

Hypothesis: There is no correlation between the size of the organism and the size of the cell.

Observations:
Spinal Cord - 13 um
Buttercup - 39 um
Shark Brain - 36.4 um
Enor's Cheek - 80 um
Algae - 169 um


Our observations support our hypothesis in the sense that cell size had no relation to the size of the organism (seeing as how a human is larger than a tiny piece of algae). Our measurements were based on what appeared to be the average cell size - we measured the longest points.


Name:  
Username:  msimakov@brynmawr.edu
Subject:  Lab 3
Date:  2003-09-24 14:48:07
Message Id:  6609
Comments:
Mariya Simakova, Lindsay Updegrove

Hypothesis:
Cell size has no direct relation to the size of the organism. The size of the organism is determined by the number of cells that it is composed of.

Observations:

Human Cells:

Vena Cava: Average 85um
Cheek cells: Average 70um

Plants:

Buttercup Root Cells: Average 46um
Algae cells: Average 50um

Conclusion:
Our observations show that our intitial hypothesis is correct. A human organism is composed of cells of different sizes. If
cell size determined the size of the organism, the sizes of the human cells would have been the same. Moreover, a buttercup is bigger than an algae plant, but its cells are smaller. Therefore, there is no direct relationship between the cell size and the size of the organism. Rather, we can hypothesize that each organism is composed of different cells and that the cell size varies with the particular kind and function of each cell (for instance, see the discrepancy in the size of different human cells).


Name:  
Username:  Anonymous
Subject:  Cell/Size correlation
Date:  2003-09-24 14:48:48
Message Id:  6610
Comments:
Diana Medina
Jessic Knapp

Hypothesis: Size of cell ought not have a direct correlation with the size of the orgmanism. Rather, the relation ought to lie in the amount of cells an organism has in accord with it's size.

Butter Cup: 12um at 40x
Moss: 7um at 40x
Cheek: 1um at 40x

Based on the latter observations we conclude that our hypothesis holds true for the experiment. As shown, the size of a cheek cell was many times smaller than that of a butter cup cell. As is clear, a human is many times larger than a butter cup plant which goes to show that size of cell and size of organism are not directly correlated.


Name:  Anna & Alison
Username:  amarcini@brynmawr.edu
Subject:  Cells
Date:  2003-09-24 14:53:49
Message Id:  6611
Comments:
Hypothesis: We propose that there is no direct correlation between the size of an object and the size if its cells; i.e. A tree's cells will not be larger than an acorn's cells simply because of the size difference.

Cheek Cells
-cell 1- 5 um
-cell 2- 4 um

Note: In the animal/ human cells it was more difficult to measure, because the walls were globulous and not really as thick, or as perceptible as plant cell walls. All data has been converted.

Tonsil
-cell 1- 2.6 um
-cell 2- 4.6 um

Shark Brains
-cell 1- 13 um
-cell 2- 39 um

Human Skeletal Muscle
-cell 1- 22 um
-cell 2- 40 um

Spinal Cord
-cell 1- width 15 um, length 40 um
-cell 2- width 25 um, length 30 um
-cell 3- width 20 um, length 20 um

Alison and I agreed that our hypothesis was workable, but it still remains difficult to come upon an answer. The spinal cord is fairly large, and its cells were the largest, however, the shark brain cell was also comparable, as was cell 2 from the Human Skeletal Muscle. We have no conclusion other than that we believe that the size of cells has nothing to do with the size of the thing they make up. Since cells divide to make new cells, we really cannot make any sort of correlation between the sizes.


Name:  
Username:  Anonymous
Subject:  Micro
Date:  2003-09-24 14:55:24
Message Id:  6612
Comments:
Stefanie Fedek and Adina Halpern

Hypothesis:
there is no correlation between cell size and organism size.

In order to prove we will look at cells from organisms of varying sizes. we will look at more than one cell from each organism in order to account for possible variation within the organism.

Observations:

1. Corn Cell: 70 um

2. Human Cheek Cell: 50 um

3. Elodia Cell: 100 um

We observed that there is no correlation between the size of an organism and the cell size of that organism.


Name:  Julie and Nomi
Username:  Anonymous
Subject:  Cell size vs. organism size
Date:  2003-09-24 14:58:48
Message Id:  6613
Comments:
Our hypothesis was that cell size would not be related to organism size.

Sub-hypotheses included: Cell shape will depend on presence/absence of a cell wall; cell size will depend on presence/absence of a cell wall; cell shape and size will depend on the function of the cell in the organism.

We based our hypotheses on previous observations collected in former biology classes.

We recorded the size measurements and shapes of cells from the bulbilis moss, earthworm cells and human nasal cells. Our data were:

Moss cells (In moss stem): long and thin, average 1,800 micrometers. Shape: rectangular.

Earthworm cells: average 100 micrometers. Shape: roughly oval or round.

Human nasal cells: average 650 micrometers. Shape: globby; roughly oval or round.

Our data and observations support our hypotheses, suggesting that larger organisms do not necessarily have larger cells (moss cells > human cells), and that cell size and shape does depend on absence or presence of a cell wall (the plant cells were decidedly larger, on average, and more rectangular or box-shaped than the animal cells).

We were not able to collect any data with regards to cell function; however , a new hypothesis would be that the cells in moss stems are long and thin because they are vascular cells, and that vascular cells are generally longer and thinner.


Name:  
Username:  rmerilie@brynmawr.edu
Subject:  Lab #3
Date:  2003-09-24 15:00:11
Message Id:  6614
Comments:
Rochelle Merilien, Christina Alfonso, Denise Erland

Hypothesis: We believe that cell size is irrelevant in relation to the size of an organisim.

Measurements:
Spinal Cord 14.0 um
Worm 36.4 um
Buttercup 44.2 um

Our findings suggest that the larger the organism, the smaller the cell size; however it is important to note the limited number of specimens that we measured (3). We are not confident in making any conclusion from our measurements. We feel we would need more specimens of different sizes to have a more inclusive summary of possible observations.


Name:  
Username:  fmichael@brynmawr.edu
Subject:  Lab 3
Date:  2003-09-24 15:07:39
Message Id:  6616
Comments:
Flicka Michaels
Alice Goldsberry

Hypothesis: Smaller organisms are made up of smaller cells and larger organisms are made of larger cells.

Observations:
Moss- 3 OR at 10x = 30 um for round cells
1 OR at 10x = 10 um for striped cells

Corn Prop root- 27 OR at 40x= 70.2 um

Human trachea- 7 OR at 40x= 18.2 um

Earthworm- 12 OR at 40 x = 31.2

Our collection of observations disproved our theory because the corn prop roots and the earthworm both had bigger cells than the trachea cells, although humans are larger organisms than earthworms. Also, corn prop roots had a significantly larger measurement of cells than humans even though they are around the same size.
So we concluded that the because the organism is large, that does not necessarily mean that the cells of that organisms are large and vica versa.


Name:  Ramatu Kallon, Patricia Palerm
Username:  jhawkins@brynmawr.edu
Subject:  Lab #3 Romatu Kallon, J'London Hawkins, Patricia Palermo
Date:  2003-09-24 15:10:01
Message Id:  6617
Comments:
HYPOTHESIS:

We assert that the size of a cell is NOT dependent upon the size of the entire organism.

MOTIVATION:

Although we HUMANS are large organisms in relationship to that of a plant, we are compoosed of extremely small cells. Each cellular size depends not upon the size of the organism but is POSSIBLY correlated to the function that cell executes in relationship to the larger body.

OBSERVATIONS:

WORM CELL 1430.0 um/OR @ LENS 4X
FLOWER CELL 91.0 um/OR @ LENS 40X
J'LONDON'S CHEEK CELL 500.0 um/OR @ LENS 100X

We find that our collected data supports the original hypothesis, in that the cheek cell of a 5'9.5" human being weighing an undisclosed amount proved to be the SMALLEST cell. While the worm, which is often times squished by the feet of human beings proved to have the LARGEST cell.


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