Thursday, December 16, 2010

Harvest of Fear

Harvest of Fear


Should we Grow GM Crops?

Instructions: Read the page and click YES or NO, reach the 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.
1A. A GM Crop is a genetically modified food crop.

2. List 2 arguments FOR the growing of GM crops
2A. There are possible health benefits from eating GM food because more nutrients and vitamins can be added. Also, farmers can be positively impacted by GM crops because they won't need to use pesticide or herbicide.

3. List 2 arguments AGAINST the growing of GM crops.3A. There are possible health risks from eating GM food for people, GM food can cause allergies, some studies show. Also, farmers are negatively affected because of a patent of GM crops, or it may just be too expensive for them.

*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?
4A. It took me four tries to have a successful season of corn.

What’s for Dinner?

*Click on the foods on the table to see what research is being done to bioengineer the foods.

5. List two foods and describe how they are being modified.
5A. Potatoes are being modified to be less absorbent, so that when they are fried they do not soak up all the oil. This way they can be healthier. Coffee beans are being modified so that they are not as high in caffeine.


*Read the article titled “Are GM Food Sufficiently Regulated in the US?”

Do you think food should be labeled if it has been genetically modified? Why or Why not?

Yes, I do think food should be labeled if it has been genetically modified. The people have a right to know what they are eating. It is only fair, also someone may have severe allergic reactions to something that is now in a certain food due to genetic modification and they could die. So the food should be labeled because the public needs and should know so that they are aware of the risk they are taking.

Finished? Go to and type "genetic engineering" in the search field. Browse some of the sites that pop up.

Write down any of the sites you visited below.

Monday, December 6, 2010




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")
1A. Differences in identical twins accumulate throughout time due to the environment. Identical twin epigenomes start out the same since they share the same environment, but as they age and time goes on, their environments start to differentiate. Different environmental factors add or remove epigenetic tags which alter the epigenome and influence the twins. One twin will have a certain gene silenced that another does not.

2. Name 3-4 environmental factors that influence the epigenome.
2A. Diet, physical activity, stress, and toxin exposure can alter the epigenome.

3. What is an imprinted gene?
3A. An imprinted gene is a gene that comes from a parent chromosome and contains epigenetic tags that did not get erased.


1. Discuss factors in your daily life (ie. Diet, exercise, stress etc.) that could be affecting
your epigenome
1A. The type of foods I eat, amount of exercise I do, and the level of stress I have can affect my epigenome.


1. Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that
pup's response to stress will be.
1A. A high-nurturing mother rat will shape her pup's epigenome by constantly licking, nursing, and grooming its pup. The pup will then react calmly to stress, where a poorly nurtured pup will be very nervous and intimidated by stress.

2. In rats, does licking by the mother activate, or deactivate her pup's GR gene?
2A. Licking by the mother activates a pup's 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.
3A. In the hippo campus, the part of the brain that controls stress, cells will produce Glucocorticoid Receptor protein amounts that vary depending on how well it is nurtured. During fight or flight cortisol, a hormone, is produced in the hippo campus, it will bind to the GR protein and send out signals that tell the rat to be calm. Rats with a lot of GR will have a lot more signals telling it to calm down and they will not be as stressed as a rat with very few GR proteins and very few calm signals.

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.
4A. I think that the basic idea of the rule of high-nurturing and low-nurturing for rats applies to humans. If a child is brought up by negligent parents, it will be less secure and happy than a child that was brought up by loving parents.


1. Explain how the food we eat affects gene expression.
1A. The food we eat affects our gene expression by determining how we look. The food you eat contains nutrients that are removed and put into metabolic pathways. They are them shaped into molecules that are used in the body. One pathway is used to create methyl groups. When you eat food that contains good amounts of methyl, you are more fit than someone who eats food with very little methyl.

2. Can the diets of parents affect their offspring's epigenome?
2A. Yes, when a woman is pregnant, her diet is very important. She needs to intake foods that have plenty of methyl. She also needs to cut back on fatty foods and eat healthy. These choices affect the child by making it healthy (but all that can change by the choices it makes in its life). The father's father's diet is important because the amount of food he was able to have can allow a grandchild to live long and prosper, or have a short life. Studies show that grandfathers who had less to eat actually had extended life compared to those with an abundance of food, thus grandchildren of these people will encounter the same effects the grandfathers received.


1. How does Dietary methyl influence gene expression?

1A. Dietary methyl influences gene expression because the amount of methyl you retain from nutrients in your food keep you healthy. If you have a methyl-deficient diet you are prone to obesity.

2. Why do Toxins affect gene methylation?

2A. Toxins affect gene methylation by damaging your health. For example, the chemical BPA can cause endocrine problems like obesity, stunted growth, and birth defects.

Tuesday, November 23, 2010

DNA Fingerprinting Lab

1. DNA is unique for everyone. The only exception is if a person has what?
1A. If a person has an identical twin then their DNA is not unique.

2. What are DNA fingerprints used for?
2A. DNA fingerprints are used for many things such as identifying a biological parent, or as evidence in a crime.

Part 1 “It Takes a Lickin”
3. What “crime” was committed?
3A. Jimmy's property had been damaged (his lollipop was eaten).

4. What bodily fluid was removed from the “crime scene” to get DNA?
4A. To eat a lollipop you have to lick which means a trace of the criminal's saliva was left. The saliva is what will be used to create a DNA fingerprint.

Part 2 “DNA Fingerprinting at the NOVA Lab”

5. What does a restriction enzyme do?
5A. A restriction enzyme chops the DNA at different places like a pair of scissors. The location in which the enzyme cuts depends on how the molecule/gene is coded. A certain sequence can make a certain enzyme cut at a certain spot.

6. What is agarose gel?

6A. Agarose is a thick gelatin-like matter that strains molecules, letting smaller DNA particles percolate better than larger ones.

7. What is electrophoresis?

7A. Electrophoresis is the process in which molecules move along an electric current. Since opposite poles attract, the negative DNA bits ar

e pulled towards the positive end of the tray.

8. Smaller fragments of DNA move
easier than longer strands.

9. Why do you need to place a nylon membrane over the gel?
9A. You need to place a nylon membrane over gel so you can pick it up easily. It is pretty difficult to pick up the gel by itself, but the nylon membrane, a paper-like substance, will suck up the DNA.
10. Probes attach themselves to DNA fragments (on nylon membrane).

11. Which chemical in your “virtual lab” is radioactive?
11A. The chemical(s) in the lab that are radioactive are the probes.

12. Sketch your DNA fingerprint.

13. Based on your DNA fingerprint, who licked the lollipop?
13A. The culprit was Honey Sweet.

Click on the Link “DNA Workshop” (if this link won't load, scroll down to the bottom where it says "try the non-java script version)
Once you’re there, go to the link “DNA Workshop Activity” and practice with DNA replication and protein synthesis.

Browse the DNA Workshop site.

14. What kinds of things could you do at the DNA workshop?

14A. I was able to go through the process of replicating DNA and synthesizing protein in which I matched up base pairs, transcribe DNA, match anticodons,

Find an Article about DNA

Go to

15. Read an article about genetics at this site that you might find interesting, or use the "Search" box in the upper right hand corner to search for DNA fingerprinting.

Title of Article

DNA Tests Show African Elephants Are Two Species

By Hillary Mayell/August 24, 2001

In the past, elephants have been split into two species: Asian and African. Now, according to a DNA fingerprinting test, the African forest and savanna elephants are two completely different species. Almost as diversified as a lion and tiger. Unfortunately, if this information is correct, then elephants are in even more danger than we previously thought. This theory is based on Different Characteristics and Major Implications. Physically the savanna and forest elephants vary by their overall body, tusk, ear, and skull shape. Socially they differ as well, savanna elephants travel in much larger units than forest elephants. Of course, scientists have been educated on these trait differences for a while. It was found that these variations were not strong enough to back up the theory. That is where DNA comes in, previously these DNA tests were not very accessible, but are now. It is essential that this theory is accepted because it can help specify how to better save the elephants. More specific strategies can now be put into place. For example: logging imposes a major threat to forest elephants, whereas expansion of agriculture is lethal to savanna elephants.

Wednesday, November 3, 2010


1. Which stage does the following occur

Chromatin condenses into chromosomesProphase, The first mitotic stage in which the copied DNA and protein condense to grow mitotic spindle.
Chromosomes align in center of cell.Metaphase, pressure is put on the spindle fibers which causes the chromosomes to align.
Longest part of the cell cycle.Interphase, the DNA duplicates, the centrioles split, and proteins produce. Can last 12-24 hours.
Nuclear envelope breaks down.Prometaphase, the nucleus is not visible anymore, spindle fibers go on top of each other in the cell center.
Cell is cleaved into two new daughter cells.Cytokinesis, spindle fibers start degrading until only a small part is left. It is in this part that a ring is created and eventually cleaves the cell into two daughter cells.
Daughter chromosomes arrive at the poles.Telophase

Watch the video carefully.

2. The colored chromosomes represent chromatids. There are two of each color because one is an exact duplicate of the other.

--How many chromosomes are visible at the beginning of mitosis? At the very beginning none, but towards the middle four.

-- How many are in each daughter cell at the end of mitosis? In the very end there are none, but in Cytokinesis there are three.

--The little green T shaped things on the cell are: Centrioles.

-- What happens to the centrioles during mitosis? They divide.

3 . Identify the stages of these cells:

This is metaphase because the chromosomes are all aligned.This stage is Cytokinesis because the daughter cells are being cleaved.This stage is Prophase because the mitotic spindles are forming.

Another Mitosis Animation

Go to

View the animation and sketch the cell in:


The chromosomes are condensing to form long mitotic spindles.


The spindle fibers are pressurized which causes the chromosomes to align in the center of the cell.


The chromosomes and spindle fibers are being pulled apart to opposite ends of the cell by protein. The chromosomes are being stretched out and turning very long and thin. Finally two nuclear envelopes envelope the stretched out chromosomes and the cell splits into two daughter cells.

Onion Root Tip - Online Activity

Read the introduction, then click the “next” button.

You will have 36 cells to classify. When you’re finished, record your data in the chart below.


Number of cells


Percent of cells

(calculate: number of cells divided by total cells x 100 )

55%27%8.3%5%2.7%100 %

Mitosis in Whitefish & Onion Roots

For each organism, identify the stage of mitosis.

View 1
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