Results:
Pouring the sodium silicate solution into the beaker containing the alcohol produced an immediate reaction. The polymer turned a creamy color and crumbled easily. It refused to stick together at first, but when we did get it to stick together, it looked like a snowball. The mixture was translucent a shiny.
While forming the ball, the polymer felt sticky and slimy until we got the polymer dried a little bit. However, the first time we dried the polymer, it crumbled, so the second time we let it air dry.
The rebound of the normal polymer was about 8cm. It also bounced around a lot. When we refrigerated the polymer, it became smaller and harder. This caused it to bounce higher.
Questions:
1. What characteristics are similar between your two types of polymers you have made? Differences?
The two polymers were similar because their solutions joined to create another object. The two polymers are different because the first polymer was more flexible and held shapes better. The second polymer was harder to shape and crumbled quite often.
2. Most commercial polymers are carbon based. What similar properties do carbon and silicon share that may contribute to their abilities to polymerize?
Carbon and silicon both make four chemical bonds which gives the capability to branch out in four directions. This is also how the two are able to make long chains.
3. Plastics are made of organic (carbon based) polymers. What similarities do the silicone polymer share with plastics?
They both use organic materials, however, while silicone is completely made form organic sources, plastic is only half organic. Monomer plastics are mostly made from organic substances, which make plastics and silicone even more similar. Both plastics and silicones are key ingredients to making polymers. Silicones can also make a type of plastic. It is said that silicone is able to replace plastic in toys, which would make them much safer.
4. How did you know that a chemical reaction had taken place when the two liquids were mixed?
We knew that a chemical reaction had taken place between the two liquids because they started to show a physical change.
5. How could you find out what liquid was pressed out of the mass of crumbled solid as you formed the ball?
We could have tested the DNA of the liquid to find out what it was.
6. Compare you ball with those of other members of the class. How many properties can you compare (e.g., diameter of sphere versus height of bounce)?
The group in front of us had made a much larger polymer. It was about a quarter in size, while ours was about a dime. Also, their polymer did not crumble. We think this could be because our group held it too much.
Conclusion
This experiment was much like the other one we did in the form of basic procedures and results. However, both of the polymers would yield different results when used for daily purposes. For example, the glue polymer is more flexible and would be able to withstand much more strain than the sodium silicate polymer. The sodium silicate polymer is much more logical to create however, because it is made from sustainable substances while glue can melt. It is rather interesting to see how substances of the same characteristics can have so many different properties that makes them fell different.
Monday, March 14, 2011
Polymer Investigation
Our group was: Haley Ciccone, Holden Long, and Keara Burke
This is the lab sheet our group put together.
Problem: How does the tacky glue change the physical and chemical properties of the polymer?
Hypothesis: When the white Elmers glue (polyvinyl acetate) is replaced with tacky glue, the resulting polymer will be stretchier.
Background Info: Tacky glue is thicker than normal white glue. It dries faster and is a stronger adhesive. Tacky glue is also a PVA substance, meaning it must be kept from freezing. Otherwise it will become extremely stiff and become hard to move. When dehydrated, it
Title: Tacky Glue Polymer
Problem: How does the tacky glue change the physical and chemical properties of the polymer?
Hypothesis: When the white Elmers glue (polyvinyl acetate) is replaced with tacky glue, the resulting polymer will be stretchier.
Background Info: Tacky glue is thicker than normal white glue. It dries faster and is a stronger adhesive. Tacky glue is also a PVA substance, meaning it must be kept from freezing. Otherwise it will become extremely stiff and become hard to move. When dehydrated, it
will peel off of glass, metal, and plastic.
Materials:
- Tacky glue - polyvinyl acetate
- Plastic spoon
- 200 or 250 mL beaker (Pyrex)
- 500 mL beaker (Pyrex)
- Stirring rod
- Graduated cylinder
- 525 mL of water
- 2 tsp of borax (hydrated sodium borate)
- cm ruler
- Square of paper towels (or any absorbing material used for cleaning)
- Refrigerator (with an average temperature of 1.7- 3.3 degrees Celsius
1. Arrange the materials at the head or front of a flat surface.
2. Add 400 ml of water to the larger beaker.
3. Add 2 tsp. of borax to water and stir until dissolved.
4. Pour 40 mL of tacky glue into small beaker.
5. Add 5 mL of water to the adhesive.
7. Clean the stirring rod.
8. Stir the borax compound.
9. Blend the glue and water for about 30-60 seconds, or until fully integrated.
11. Calculate 25 mL of the Borax solution that was just stirred with the graduated cylinder.
12. Deposit the solvent matter into the small beaker.
13. Coalesce the two elements, both solvent and solute, with the stirring rod.
14. Examine its features and record any results.
15. If needed, test the rebound and flexibility of the polymer just before cleaning the materials.
Stretchy Test Procedures: One ruler and a flat surface (preferably a level table) is needed to perform this experiment. After the polymer has successfully been formed, and is set to a comfortable, pliable room temperature, the trial(s) may commence. Align the ruler with the edge of the table; have the side with the centimeters facing the edge. Mold the sticky substance into an oval shape. Firmly grasp the polymer with both hands, leaving about one to two centimeters of material between fists. Stretch the matter at a controlled pace so to be sure that observations are able to be recorded, as well as allowing the polymer to adjust to the change in physical properties. How do you know when to stop stretching? When the link between the two wedges disperse in thin filaments, or the bridge suddenly splits, then it is a definite sign to halt the operation and record significant data. Depending on the fiber being tested, another ruler may need to be added to the materials in order to document accurate measurements. However, this is just in case the polymer spreads wider than originally expected (30 cm). Also, this test will need to be reiterated two to three more times in order to regulate an average calculation of its break-point. Compare and contrast with previous test results, as well as separate experiments.
Stretchy Test Procedures: One ruler and a flat surface (preferably a level table) is needed to perform this experiment. After the polymer has successfully been formed, and is set to a comfortable, pliable room temperature, the trial(s) may commence. Align the ruler with the edge of the table; have the side with the centimeters facing the edge. Mold the sticky substance into an oval shape. Firmly grasp the polymer with both hands, leaving about one to two centimeters of material between fists. Stretch the matter at a controlled pace so to be sure that observations are able to be recorded, as well as allowing the polymer to adjust to the change in physical properties. How do you know when to stop stretching? When the link between the two wedges disperse in thin filaments, or the bridge suddenly splits, then it is a definite sign to halt the operation and record significant data. Depending on the fiber being tested, another ruler may need to be added to the materials in order to document accurate measurements. However, this is just in case the polymer spreads wider than originally expected (30 cm). Also, this test will need to be reiterated two to three more times in order to regulate an average calculation of its break-point. Compare and contrast with previous test results, as well as separate experiments.
Results:
When we tested the flexibility of the tacky glue polymer, it stretched to 18 cm. We tested the flexibility again after putting the polymer in the fridge. It was able to stretch up to 59 cm. We also tested the rebound. At room temperature, the polymer's rebound was between 8-11. After being cooled, the polymer's rebound was 13.
We found that a different type of glue was enough to change the physical properties of the polymer: for instance, it resulted in much higher flexibility. Our hypothesis was proven correct.
Addiction
The brain is made up of groups of neurons which are responsible for certain tasks. Near the center of the brain is a system called the "reward pathway": its job is to transfer dopamine and create the feeling of pleasure. Recreational drugs work by mimicking the brain's inhibitory and excitatory proteins and abusing this pathway to create a "high" in the user.
These drugs have consequences; they affect the reward pathway's ability to create pleasure and wire other parts of the brain, creating an impulse to continue using a drug (i.e. addiction).
These drugs have consequences; they affect the reward pathway's ability to create pleasure and wire other parts of the brain, creating an impulse to continue using a drug (i.e. addiction).
Sunday, January 9, 2011
Harvest of Fear
Should we Grow GM Crops?
Instructions: Read the page and click YES or NO, reach the next...click YES or NO...etc until you’ve read all the arguments -- You will need to do this 12 times in order for your votes to be tallied. Navigate the site, each of the bold headings below are links within the site
1. What is a GM Crop?
GM stands for genetically modified (although that's a very misleading acronym, and one that probably shouldn't be used). Genetically modified crops have had genes added, removed or modified.
2. List 2 arguments FOR the growing of GM crops
Instructions: Read the page and click YES or NO, reach the next...click YES or NO...etc until you’ve read all the arguments -- You will need to do this 12 times in order for your votes to be tallied. Navigate the site, each of the bold headings below are links within the site
1. What is a GM Crop?
GM stands for genetically modified (although that's a very misleading acronym, and one that probably shouldn't be used). Genetically modified crops have had genes added, removed or modified.
2. List 2 arguments FOR the growing of GM crops
- Genetically modified food potentially means less pesticide and herbicide.
- Genetically modified food is one of the best hopes for feeding a rapidly expanding world population.
3. List 2 arguments AGAINST the growing of GM crops.
- Genetically modified food is believed to present a potential health risk.
- Genetically modified food may have small farmers be indentured to large farms.
*Read some of the reader’s responses.
Engineer a Crop
4. Practice this simulation until you get the largest ears of corn. How many times did it take you?
Fourteen.
What’s for Dinner?
*Click on the foods on the table to see what research is being done to bioenginner the foods.
5. List two foods and desribe how they are being modified.
What’s for Dinner?
*Click on the foods on the table to see what research is being done to bioenginner the foods.
5. List two foods and desribe how they are being modified.
Corn is being modified to have "altered oil profiles, amino-acid compositions, seed color, starch content, and ability to tolerate drought."
Cotton is being modified to have altered fiber quality that is also moth resistant and drought tolerant.
Viewpoints
*Read the article titled “Is GM Food Sufficiently Regulated in the US?”
Do you think food should be labeled if it has been genetically modified? Why or Why not?
Cotton is being modified to have altered fiber quality that is also moth resistant and drought tolerant.
Viewpoints
*Read the article titled “Is GM Food Sufficiently Regulated in the US?”
Do you think food should be labeled if it has been genetically modified? Why or Why not?
There doesn't seem to be any serious reason to not label genetically modified food, besides consumers rejecting the food solely on the basis of being modified, rather than for any known health risks (which is pretty absurd, but apparently this happens often). So, if consumers are responsible enough to not reject a product solely based on being modified, for the sake of "transparent" government and science, genetically modified food should be labeled in the U.S.
Wednesday, January 5, 2011
Cloning in Focus
1. Who is Dolly?
In the context of genetics, Dolly is a cloned sheep, as well as the first mammal to be cloned. Dolly was cloned in Great Britain.
2. When a zygote divides into to separate cells, it is called Artificial Embryo Twinning.
3. Somatic cells are also called: adult cells.
4. In order to clone a gene, a gene is inserted into a strand of DNA, usually a plasmid.
5. In order to create an embryo from a somatic cell, the donor egg cell must have its nucleus removed.
Click and Clone
6. List all the materials needed to clone a mouse.
7. Place the following steps in the correct order.
8. There are two time gaps in the process of cloning. What are they? (ie. what do you have to wait for?) It takes time for the DNA to be reprogrammed and for the chemical to stimulate cell division.
9. What color with (sic) the cloned mouse be? Brown. What is the name of this mouse? Mimi.
Why Clone?
10. Why is cloning extinct animals problematic? Locating the DNA of an extinct species is very difficult.
11. What are some reasons a person might want to clone a human? To allow infertile couples to have "children" and to replace deceased children (although the latter seems awfully questionable).
The Clone Zone
12. What animal was cloned in 1885? The sea urchin.
13. How did Spemann separate the two cells of the embryo of a salamander in 1902? The embryo was split with a baby's hair.
14. The process of removing a nucleus is called enucleation.
15. In 1952, the nucleus of a frog embryo cell was placed into a donor cell. Did it work to clone the animal? No.
16. Can the nucleus of an adult cell be injected into an egg cell and produce a clone? Yes.
17. Why are mammals hard to clone? Their DNA is complex, and their development is largely based on their environment.
18. What were the names of the first two cloned cows? Fusion and Copy.
19. In what year was the National Bioethics Advisory Council formed? 1995
20. The first mammal clone to be produced from an adult (somatic) cell? (sic) Dolly.
21. What do scientists do to adult cells to make them "behave" like embryos? The electric shock technique simulates fertilization by sperm, causing the cell to divide.
22. Transgenic, cloned sheep were used to produce what medical protein? Factor IX
23. What is a stem cell? An undifferentiated cell whose daughter cells may differentiate into other types of cells.
Cloning Myths
24. Briefly describe in your own words, (sic) why CC the cat was not identical in color to Rainbow, even though she was a clone?
Very early in her development, each of Rainbow's cells "turned off" one entire X chromosome - thus turning off either the black color gene or the orange one. In short, the genes are identical, but they are expressed differently.
25. What is "nature vs nurture"?
Nature vs. nurture is the supposed conflict between genetics and parenting: a continuing and stagnant argument over whether or not parenting has a significant influence on the child.
Is it Cloning or Not?
26. For each of the following scenarios, indicate YES (it is cloning) or NO (it is not cloning)
(NO)Sperm taken from a mole goat is combined with a female's egg in a petri dish. The resulting embryo is implanted into the female's uterus to develop
(YES)A sheep embryo, composed of 16 cells, is removed from the mother's uterus and separated into individual cells. Each cell is allowed to multiply, creating 16 separate embryos, which are then implanted in different female sheep to develop to maturity.
(NO)A cow with many desirable traits is stimulated with hormones to produce a number of egg cells. Each of these eggs is fertilized and implanted into a surrogate mother.
(NO) In vitro fertilization
(YES) Cell nuclei from an extinct wolly mammoth are placed into enucleated cow cells.
27. Define or describe each of the following processes (you may need to reset the Cloning or Not Screen)
In vitro fertilization
Fertilization of an embryo by sperm cells within a test tube.
Embryo splitting
An embryo splitting evenly, causing the development of two identical organisms.
Somatic Cell Nuclear Transfer
Creating a clonal embryo using an ovum with a donor nucleus.
Multiple Ovulation Embryo Transfer
A process to produce multiple copies of an animal.
Artificial Insemination
Sperm is placed into a female reproductive track in an attempt to cause fertilization.
What Are the Risks of Cloning?
28. What is one reason why cloning animals has such a high failure rate?
Pregnancy frequently fails.
29. What is a telomere and how does it affect cloned animals?
A telomere is "junk DNA" at the beginning and end of each chromosome.
30. Pick one of the questions to ponder and ....ponder it. Write a brief essay on your thoughts and opinions.
If a clone originates from an existing person, who is the parent?
The term "parent" is a pretty meaningless when applied to artificially produced organisms. After referring to a number of different dictionaries, there appears to be two definitions of "parent": the more common one is "the person who raises a child," which seems pretty self explanatory. The second definition is "one of the two organisms from whom one is immediately biologically descended," but in this case there would only be one person: the organism which is cloned is, by definition, a clone of itself. Obviously refutable paradoxes in the English language are such fun!
In other words, there are two different kinds of parents: biological and social. Biological parents are the entities from which an organism descends. Most organisms only have biological parents; they are not raised, and learn to survive on their own (i.e. spawning salmon). Social parents are organisms which raise a child (not necessarily their own, but usually). Some species reproduce asexually, which is, by definition, cloning. Obvious examples of asexual reproduction are amoebas and pea plants.
In the context of genetics, Dolly is a cloned sheep, as well as the first mammal to be cloned. Dolly was cloned in Great Britain.
2. When a zygote divides into to separate cells, it is called Artificial Embryo Twinning.
3. Somatic cells are also called: adult cells.
4. In order to clone a gene, a gene is inserted into a strand of DNA, usually a plasmid.
5. In order to create an embryo from a somatic cell, the donor egg cell must have its nucleus removed.
Click and Clone
6. List all the materials needed to clone a mouse.
- DNA from the mouse to be cloned
- A surrogate mother mouse
- Sharp pipette
- Blunt pipette
- A chemical to stimulate cell division
- Petri dishes
- Microscope
7. Place the following steps in the correct order.
a) Isolate all of the donor cells
b) Remove and discard the nucleus from the egg cell
c) Transfer the somatic cell nucleus into the egg cell
d) Stimulate cell division
e) Implant embryo into a surrogate mother
f) Deliver baby
9. What color with (sic) the cloned mouse be? Brown. What is the name of this mouse? Mimi.
Why Clone?
10. Why is cloning extinct animals problematic? Locating the DNA of an extinct species is very difficult.
11. What are some reasons a person might want to clone a human? To allow infertile couples to have "children" and to replace deceased children (although the latter seems awfully questionable).
The Clone Zone
12. What animal was cloned in 1885? The sea urchin.
13. How did Spemann separate the two cells of the embryo of a salamander in 1902? The embryo was split with a baby's hair.
14. The process of removing a nucleus is called enucleation.
15. In 1952, the nucleus of a frog embryo cell was placed into a donor cell. Did it work to clone the animal? No.
16. Can the nucleus of an adult cell be injected into an egg cell and produce a clone? Yes.
17. Why are mammals hard to clone? Their DNA is complex, and their development is largely based on their environment.
18. What were the names of the first two cloned cows? Fusion and Copy.
19. In what year was the National Bioethics Advisory Council formed? 1995
20. The first mammal clone to be produced from an adult (somatic) cell? (sic) Dolly.
21. What do scientists do to adult cells to make them "behave" like embryos? The electric shock technique simulates fertilization by sperm, causing the cell to divide.
22. Transgenic, cloned sheep were used to produce what medical protein? Factor IX
23. What is a stem cell? An undifferentiated cell whose daughter cells may differentiate into other types of cells.
Cloning Myths
24. Briefly describe in your own words, (sic) why CC the cat was not identical in color to Rainbow, even though she was a clone?
Very early in her development, each of Rainbow's cells "turned off" one entire X chromosome - thus turning off either the black color gene or the orange one. In short, the genes are identical, but they are expressed differently.
25. What is "nature vs nurture"?
Nature vs. nurture is the supposed conflict between genetics and parenting: a continuing and stagnant argument over whether or not parenting has a significant influence on the child.
Is it Cloning or Not?
26. For each of the following scenarios, indicate YES (it is cloning) or NO (it is not cloning)
(NO)Sperm taken from a mole goat is combined with a female's egg in a petri dish. The resulting embryo is implanted into the female's uterus to develop
(YES)A sheep embryo, composed of 16 cells, is removed from the mother's uterus and separated into individual cells. Each cell is allowed to multiply, creating 16 separate embryos, which are then implanted in different female sheep to develop to maturity.
(NO)A cow with many desirable traits is stimulated with hormones to produce a number of egg cells. Each of these eggs is fertilized and implanted into a surrogate mother.
(NO) In vitro fertilization
(YES) Cell nuclei from an extinct wolly mammoth are placed into enucleated cow cells.
27. Define or describe each of the following processes (you may need to reset the Cloning or Not Screen)
In vitro fertilization
Fertilization of an embryo by sperm cells within a test tube.
Embryo splitting
An embryo splitting evenly, causing the development of two identical organisms.
Somatic Cell Nuclear Transfer
Creating a clonal embryo using an ovum with a donor nucleus.
Multiple Ovulation Embryo Transfer
A process to produce multiple copies of an animal.
Artificial Insemination
Sperm is placed into a female reproductive track in an attempt to cause fertilization.
What Are the Risks of Cloning?
28. What is one reason why cloning animals has such a high failure rate?
Pregnancy frequently fails.
29. What is a telomere and how does it affect cloned animals?
A telomere is "junk DNA" at the beginning and end of each chromosome.
30. Pick one of the questions to ponder and ....ponder it. Write a brief essay on your thoughts and opinions.
If a clone originates from an existing person, who is the parent?
The term "parent" is a pretty meaningless when applied to artificially produced organisms. After referring to a number of different dictionaries, there appears to be two definitions of "parent": the more common one is "the person who raises a child," which seems pretty self explanatory. The second definition is "one of the two organisms from whom one is immediately biologically descended," but in this case there would only be one person: the organism which is cloned is, by definition, a clone of itself. Obviously refutable paradoxes in the English language are such fun!
In other words, there are two different kinds of parents: biological and social. Biological parents are the entities from which an organism descends. Most organisms only have biological parents; they are not raised, and learn to survive on their own (i.e. spawning salmon). Social parents are organisms which raise a child (not necessarily their own, but usually). Some species reproduce asexually, which is, by definition, cloning. Obvious examples of asexual reproduction are amoebas and pea plants.
Monday, December 6, 2010
Epigenetics
Copied and filled out from this document: https://docs.google.com/a/pvlearners.net/viewer?a=v&pid=sites&srcid=cHZsZWFybmVycy5uZXR8OHRoLWdyYWRlLWRsY3xneDo2YWUwNDY1NGNlYWE0YWZh
The questions were asked about this website: http://learn.genetics.utah.edu/content/epigenetics/
IDENTICAL TWINS: PINPOINTING ENVIRONMENTAL IMPACT ON THE
EPIGENOME
1. Often, the physical characteristics of genetically identical twins become increasingly
different as they age, even at the molecular level. Explain why this is so. (use the
terms "environment" and "epigenome")
If the genome is the basis for what shapes a person, then the environment is responsible for changes in a person as s/he ages. Epigenetics, if one was to generalize, is the study of how these changes actually work on a physical or chemical level.
2. Name 3-4 environmental factors that influence the epigenome.
Exposure to specific chemicals (in most research pertaining specifically to epigenetics, these chemicals are artificial, but not always), the release of chemicals within the body as triggered by the environment (the fight or flight response works as an example), and...
3. What is an imprinted gene?
An imprinted gene keeps its epigenetic tags after early development.
YOUR ENVIRONMENT, YOUR EPIGENOME
1. Discuss factors in your daily life (ie. Diet, exercise, stress etc.) that could be affecting
your epigenome.
Arbitrarily applying a very new and experimental science, whose workings are not yet well understood, to one's life would, in all probability, lead to academically useless, completely unscientific and invalid observations. For instance, there is no known link between arthritis and the genome, so is arthritis epigenetic? This website assumes that it is, but that statement is impossible to prove. If I were to break a bone and experience aching in that area for years on, is it epigenetic? I'd like to say no, but that statement also is too broad to prove.
LICK YOUR RATS
1. Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that
pup's response to stress will be.
Methyl groups, which act as the epigenome, silence the GR receptor gene at birth. Nurturing from mothers causes brain impulses in the child to gradually remove these methyl groups, and allows the child to release more GR protein. The GR protein helps to reduce stress, so nurtured offspring will be calmer.
2. In rats, does licking by the mother activate, or deactivate her pup's GR gene?
Nurturing activates the GR gene.
3. Explain how cortisol and the GR protein work together in the brain to relax a rat pup.
You may draw a diagram.
Cortisol is a chemical released during the fight or flight response that can result in stress; the GR protein binds with this chemical to send calming signals, effectively counteracting the cortisol.
4. The rat nurturing example shows us how parental behavior can shape the behavior of
their offspring on a biochemical level. Relate this to humans and think about the personal
and social implications. Record your thoughts.
The repercussions are pretty implicit: that nurture can have an impact in an organism. Although if questionable studies from an experimental science are necessary for parents to care about the wellbeing of their children, then they're probably not capable of being decent parents anyway.
NUTRITION & THE EPIGENOME
1. Explain how the food we eat affects gene expression.
To be laconic: nutrition is responsible for producing methyl groups, which are believed to be responsible for handling epigenetics.
2. Can the diets of parents affect their offspring's epigenome?
Yes, it's very well accepted in the traditional sciences that diet during pregnancy can influence the development of the fetus. Of course, the connection is a bit more complex than that, and it would be a very transparent lie to say we fully understand how it works. For instance, if a child is starved somewhat while still young, his grandchildren will end up living longer lives. It will take time before anyone can pretend to understand the science.
The questions were asked about this website: http://learn.genetics.utah.edu/content/epigenetics/
IDENTICAL TWINS: PINPOINTING ENVIRONMENTAL IMPACT ON THE
EPIGENOME
1. Often, the physical characteristics of genetically identical twins become increasingly
different as they age, even at the molecular level. Explain why this is so. (use the
terms "environment" and "epigenome")
If the genome is the basis for what shapes a person, then the environment is responsible for changes in a person as s/he ages. Epigenetics, if one was to generalize, is the study of how these changes actually work on a physical or chemical level.
2. Name 3-4 environmental factors that influence the epigenome.
Exposure to specific chemicals (in most research pertaining specifically to epigenetics, these chemicals are artificial, but not always), the release of chemicals within the body as triggered by the environment (the fight or flight response works as an example), and...
3. What is an imprinted gene?
An imprinted gene keeps its epigenetic tags after early development.
YOUR ENVIRONMENT, YOUR EPIGENOME
1. Discuss factors in your daily life (ie. Diet, exercise, stress etc.) that could be affecting
your epigenome.
Arbitrarily applying a very new and experimental science, whose workings are not yet well understood, to one's life would, in all probability, lead to academically useless, completely unscientific and invalid observations. For instance, there is no known link between arthritis and the genome, so is arthritis epigenetic? This website assumes that it is, but that statement is impossible to prove. If I were to break a bone and experience aching in that area for years on, is it epigenetic? I'd like to say no, but that statement also is too broad to prove.
LICK YOUR RATS
1. Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that
pup's response to stress will be.
Methyl groups, which act as the epigenome, silence the GR receptor gene at birth. Nurturing from mothers causes brain impulses in the child to gradually remove these methyl groups, and allows the child to release more GR protein. The GR protein helps to reduce stress, so nurtured offspring will be calmer.
2. In rats, does licking by the mother activate, or deactivate her pup's GR gene?
Nurturing activates the GR gene.
3. Explain how cortisol and the GR protein work together in the brain to relax a rat pup.
You may draw a diagram.
Cortisol is a chemical released during the fight or flight response that can result in stress; the GR protein binds with this chemical to send calming signals, effectively counteracting the cortisol.
4. The rat nurturing example shows us how parental behavior can shape the behavior of
their offspring on a biochemical level. Relate this to humans and think about the personal
and social implications. Record your thoughts.
The repercussions are pretty implicit: that nurture can have an impact in an organism. Although if questionable studies from an experimental science are necessary for parents to care about the wellbeing of their children, then they're probably not capable of being decent parents anyway.
NUTRITION & THE EPIGENOME
1. Explain how the food we eat affects gene expression.
To be laconic: nutrition is responsible for producing methyl groups, which are believed to be responsible for handling epigenetics.
2. Can the diets of parents affect their offspring's epigenome?
Yes, it's very well accepted in the traditional sciences that diet during pregnancy can influence the development of the fetus. Of course, the connection is a bit more complex than that, and it would be a very transparent lie to say we fully understand how it works. For instance, if a child is starved somewhat while still young, his grandchildren will end up living longer lives. It will take time before anyone can pretend to understand the science.
Wednesday, November 3, 2010
Mitosis Worksheet
1. Which stage does the following occur
2.
How many chromosomes are visible at the beginning of mitosis? Eight.
How many are in each daughter cell at the end of mitosis? Eight.
The little green T shaped things on the cell are: centrioles.
What happens to the centrioles during mitosis? The centrioles divide.
| Chromatin condenses into chromosomes. | Prophase |
| Chromosomes align in center of cell. | Metaphase |
| Longest part of the cell cycle. | Interphase |
| Nuclear envelope breaks down. | Prometaphase |
| Cell is cleaved into two new daughter cells. | Cytokinesis |
| Daughter chromosomes arrive at the poles. | Telophase |
2.
How many chromosomes are visible at the beginning of mitosis? Eight.
How many are in each daughter cell at the end of mitosis? Eight.
The little green T shaped things on the cell are: centrioles.
What happens to the centrioles during mitosis? The centrioles divide.
3. Identify the stages of these cells.
Metaphase Telophase Prophase
4. Describe stages of mitosis according to the animation.
Prophase The chromosomes condense. The nucleus dissipates. Centrioles migrate to opposite sides of the cell. | Metaphase Spindle fibers attach to chromosomes. Chromosomes align on the metaphase plate. | Telophase The nuclear envelope reforms. The chromosomes disperse. The spindle fibers dissolve, and the cell is pinched in two by actin protein. |
5. Record data in the chart below.
6. For each organism, identify the stage of mitosis.
Yes, I know the formatting is horrible. I blame blogger.
| Interphase | Prophase | Metaphase | Anaphase | Telophase | Total | |
| Number of cells | 20 | 10 | 3 | 2 | 1 | 36 |
| Percent of cells (calculate: number of cells divided by total cells x 100 ) | 55 | 27 | 8 | 5 | 2 | 100 % |
6. For each organism, identify the stage of mitosis.
View 1 | View 2 | View 3 | View 4 | View 5 | |
| Whitefish | Telophase | Metaphase | Prophase | Anaphase | N/A |
| Onion | Anaphase | Metaphase | Interphase | Interphase | Telophase |
Yes, I know the formatting is horrible. I blame blogger.
Wednesday, October 27, 2010
Guppy Simulation
1. If being flashy and colorful attracts predators, why do you think guppies are so colorful?
Most likely to attract females; no other explanation is really plausible.
2. The fish's common name is guppy or millions fish. Its scientific name is poecilia reticulata. Average size is 3.5 cm.
3. The predator's common name is pike cichlid, its scientific name is crenicichla alta, and originates from Trinidad and Latin America.
4. Predator populations would be heavily influenced by how deep and accessible whatever part of the stream it is.
5. John Endler was an evolutionary biologist who studied wild guppy populations in Trinidad.
6.
Pool 1: Brightly multicolored with large spots.
Pool 2: Medium coloration on body and tail, with medium-sized spots.
Pool 3: Drab coloration, very small spots concentrated near tail.
7. If there are more predators in one area of the stream, then there will be less brightly colored guppies.
8. If the fish are brighter, they're much more likely to be targeted by predators.
9. Yes, in areas with less predators the brightest guppies take over the population. In areas with more predators, only the drabber fish survive. This goes with the hypothesis.
10. Two factors influence the characteristics of a guppy population: the predators, and the mates (natural and sexual selection). Saying that male guppies are caught in the crossfire more or less means this; they need to find a safe median between attracting mates and avoiding predators.
11. Guppies have different coloration in different areas of the stream based on predator population. They adapt to be drabber/brighter when predators are more/less.
12. The guppies would not attract mates because they have so little coloration, but would not be preyed upon. If there are brighter guppies in the area, they would win out over time.
13. The brighter guppies would be preyed upon and would die off due to the high amount of predators, because their coloration would be more visible to predators. Unfortune.
Most likely to attract females; no other explanation is really plausible.
2. The fish's common name is guppy or millions fish. Its scientific name is poecilia reticulata. Average size is 3.5 cm.
3. The predator's common name is pike cichlid, its scientific name is crenicichla alta, and originates from Trinidad and Latin America.
4. Predator populations would be heavily influenced by how deep and accessible whatever part of the stream it is.
5. John Endler was an evolutionary biologist who studied wild guppy populations in Trinidad.
6.
Pool 1: Brightly multicolored with large spots.
Pool 2: Medium coloration on body and tail, with medium-sized spots.
Pool 3: Drab coloration, very small spots concentrated near tail.
7. If there are more predators in one area of the stream, then there will be less brightly colored guppies.
8. If the fish are brighter, they're much more likely to be targeted by predators.
9. Yes, in areas with less predators the brightest guppies take over the population. In areas with more predators, only the drabber fish survive. This goes with the hypothesis.
10. Two factors influence the characteristics of a guppy population: the predators, and the mates (natural and sexual selection). Saying that male guppies are caught in the crossfire more or less means this; they need to find a safe median between attracting mates and avoiding predators.
11. Guppies have different coloration in different areas of the stream based on predator population. They adapt to be drabber/brighter when predators are more/less.
12. The guppies would not attract mates because they have so little coloration, but would not be preyed upon. If there are brighter guppies in the area, they would win out over time.
13. The brighter guppies would be preyed upon and would die off due to the high amount of predators, because their coloration would be more visible to predators. Unfortune.
| % of Brightest Guppies (10 generations) | % of Bright Guppies (10 generations) | % of Drab Guppies (10 generations) | % of DrabbestGuppies (10 generations) | |
| Trial 1 Guppy: Even Mix Predators: 30 Rivulus | 70% | 21% | 6% | 2% |
| Trial 2 Guppy: Even Mix Predators: 30 Rivulus, 30 Acara | 14% | 86% | 0% | 0% |
| Trial 3 Guppy: Even Mix Predators: 30 Rivulus, 30 Acara, 30 Cichlid | 0% | 3% | 2% | 95% |
| Trial 4 Guppy: Mostly Bright Predators: 30 Rivulus | 88% | 9% | 1% | 3% |
| Trial 5 Guppy: Mostly Drab Predators: 30 Rivulus, 30 Acara, 30 Cichlid | 0% | 2% | 6% | 93% |
Wednesday, October 6, 2010
Preservation of Biodiversity
Biodiversity: this is the sort of thing that people can accept on faith as a moral issue (more in the sense that it's the right thing to do than just "oh don't kill the polar bears and baby seals nooooo"). Looking at it as a practical issue, though, ignoring anything morally questionable about it, I'm actually a bit less convinced after researching it than I was before. Don't get me wrong, biodiversity something worth preserving, but we haven't really put together a very compelling argument against saving it from, well, us.
I don't have the prompt handy, but I'm pretty sure this addresses it well enough. This is also pretty excessive for a post, so I guess I should cut it off here. Bye for now.
- One common argument for preserving biodiversity is that there is potentially a great deal of medicines and other, similar benefits from species not yet studied, and if they went extinct we would lose that benefit forever. This begs the question, though, why should we bother preserving biodiversity once we've identified and safeguarded the species' of value to us? Once scientists have meticulously studied and gone through every plant and animal on the planet, this argument no longer holds much validity.
- One less common argument is that biodiversity can act as a safeguard against natural disasters: but usually when this is brought up it only refers to forestation and similar, which seems more like an argument against deforestation than anything, and that is different than biodiversity. For example, why not just select the kind of tree best suited to defending the area and leave the others vulnerable to logging and natural hazards?
- As far as food sources go, with the progress of genetic engineering to create species more useful as food sources, we could preserve the backbone of a diverse diet while allowing other species to phase out at their leisure. Sounds pretty cruel, but again, just an objective view.
- Finally, there's the obvious fact that people appreciate the aesthetics of biodiversity, but that's a pretty superficial cause to spend millions of dollars to preserve, and one that probably wouldn't drum up enough interest to, for example, save the rain forest (heh).
Yeah, I don't know. I haven't seen any other major arguments than these, and it raises questions...
Monday, August 30, 2010
Questions for the Love Canal Committee
- In a word, do you believe Love Canal to be safe or unsafe?
- Do you have any specific, credible studies to back this up?
- How recent is the studies or evidence? (if the person is against living at Love Canal, because most of the people who are against it are citing studies which occurred before the cleaning, meaning the study might no longer apply)
- When you say the area is safe, would you really be willing to live in the area yourself? (if the person is for living at Love Canal, because there seems to be a sort of double standard with some of the people that are for living there)
- Do you sincerely agree with your assigned character's stance? (if the person's character forces the person to have a certain stance on the issue, like Occidental representatives)
Love Canal
The blizzard of 1977 is largely cited as a sort of "fuse" for the chemicals under Love Canal. The snow and precipitation is said to have sunk underground, thereby pushing chemicals to the surface.
Some known effects of the chemicals on humans are cancer, liver problems, oxidative stress and other damage to the nervous system, and even birth defects.
The rest of the ecosystem was affected by the same chemicals: water and the the sediment beneath the Niagara River was contaminated, and chances are that any wildlife in the area would be just as exposed if the chemicals still occupied the Canal.
Some known effects of the chemicals on humans are cancer, liver problems, oxidative stress and other damage to the nervous system, and even birth defects.
The rest of the ecosystem was affected by the same chemicals: water and the the sediment beneath the Niagara River was contaminated, and chances are that any wildlife in the area would be just as exposed if the chemicals still occupied the Canal.
Sunday, August 22, 2010
Hazards of Oil Dispersants
Here's a brief list of the spill's alleged influence on marine life:
- The dispersant used by BP at the beginning of the spill caused internal bleeding
- The dispersant breaks down the lipid membrane of cells, so that oil enters the skin and organs more easily
- As with oil, the dispersant damages the nervous system, immune system, respiratory functions, endocrine, blood, liver and kidneys. The difference is that the both of them together is far worse than either substance on its own.
- Damage to all organs, encouraging or causing cancer, mutations or birth defects
As for whether the oil or dispersant is worse, I'm not really the sort of person to ask. Decisions like that are better left up to toxicologists, and I am of the personal belief that spreading an uneducated opinion, even if it is my own, is a very stupid thing to do. If I know only part of the situation, based on pieces of only one or two viewpoints, then I'm hardly justified to make observations based on it (regardless of how common this is). What's more, there's no such thing as a scientific opinion. This might be a rather long way to write out "I don't know enough on the subject to have a respectable opinion" but I hope this is enough that you can understand where I'm coming from.
We as a whole know only part of the situation, actually. Most information on the dispersant is locked up as "trade secrets," and as the video states, the release of information on the dispersant as requested by the government really didn't happen: the most relevant information was largely skipped over or ignored in any public reports.
An addendum for anyone who feels like hating on BP today: British Petroleum donated one BILLION dollars to be used for an alternative to oil dispersants for any future spill by any company in the oil industry, regardless of how poorly they may have handled their own problems. With all of the ridiculous spending going around it may be hard to put in perspective, but let me say it simply: that is a lot of money.
An addendum for anyone who feels like hating on BP today: British Petroleum donated one BILLION dollars to be used for an alternative to oil dispersants for any future spill by any company in the oil industry, regardless of how poorly they may have handled their own problems. With all of the ridiculous spending going around it may be hard to put in perspective, but let me say it simply: that is a lot of money.
Wow, this is a lot of text. @_@ I hope you don't expect this for every blog post!
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