Thursday, December 16, 2010

Site: http://www.pbs.org/wgbh/harvest/

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.
A GM Crop is a genetically modified crop that can withstand pesticides, herbicides, or may even have spliced genes.

2. List 2 arguments FOR the growing of GM crops.
1 argument for the growing of GM crops would be that pests and weeds can't survive because the crops have a resistance to herbicides and pesticides, allowing them the be safe while the weeds and pests are sprayed with those chemicals. Another argument is how GM crops have a longer shelf life. There are low calorie beets and even oils with less saturated fat content.

3. List 2 arguments AGAINST the growing of GM crops.
One argument talked about how children may be exposed to new allergens, or food with allergens that other foods hold, such as splicing peanuts and soybeans. Soybeans would have the peanut allergy in them. Another argument is how Monsanto was suing small farmers for growing their GM crops when the seeds from the crops blew over to their farm.

*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?
It took me two times, and on the third, I got the largest ears of corn.

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.
Potatoes are being modified to absorb less oil so that, when fried, the potatoes are less fattening and pose less of a health risk.
Scientists are also modifying cheese and adding rennet, an extract that is dried to curdle milk to make cheese, so that the cheese making process speeds up.

Viewpoints

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

Do you think food should be labeled if it has been genetically modified? Why or Why not?
I believe that GM foods should be labeled so that consumers can find out what type of food they are eating, and what the foods have been modified with. I personally would not like to eat a strawberry with flounder genes in it, even though you may not be able to taste any difference. It is mainly because of morals, and people prefer natural foods because that is what nature intended to have formed.

Monday, December 6, 2010

Epigenome

Indentical 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")

For both twins, they are exposed to the same environment early in life, but as they age, the environments begin to differ. For instance, one twin could be a social people-person. The other could become a quiet, shy adult later on and they might not be very successful.


2. Name 3-4 environmental factors that influence the epigenome.

Diet can have an affect, as well as differences in physical activity, exposure to toxins, and stress.


3. What is an imprinted gene?

An imprinted gene is a gene with epigenetic tags left on it after reproduction and during embryo development.

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Your Environment, Your Epigenome

1. Discuss factors in your daily life (ie. diet, exercise, stress, etc.) that could be affecting your epigenome.

Factors in my life that affect my life include diet, for instance. I personally have a healthily diet and I eat my 5 servings of vegetables and fruit every day. This allows me to be healthy, energized, and alert. I haven't been sick with a flu or even a cough for several years, and this is because of my diet. I exercise a good amount each day, which allows me to stay fit. I do receive a large amount of stress over time and this hurts me by adding worries in my life. Also, stress blocks out other thoughts, but I can quickly get over it.

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Lick Your Rats

1. Explain how a high nurturing mother rat shapes her pup's epigenome, and what that pup's response to stress would be.

A high nurturing mother rat would change her pup's epigenome by loosening it and allowing stress to be quickly dismissed. This allows more methyl to be released and sent away from the gene, and the loosened gene also allows GR protein to form in larger amounts, letting the rat pup calm faster.


2. In rats, does licking by the mother activate, or deactivate her pup's GR gene?

Licking 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 the calming hormone released in the rats fight or flight response. More GR proteins allow more cortisol to attach, so that the rat can calm down at fast or slow speeds.


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.

If parents nurture their children very well, those children are going to be able to withstand stress and the related subjects much more than children who were say, abused, by their parents. Those abused children would have a large amount of fear in their lives, and they would be anxious. The well nurtured children would probably become social and positive, while the badly nurtured children would end up lonely and worried.

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Nutrition & the Epigenome

1. Explain how the food we eat affects gene expression.

The food we eat affects gene expression by being broken down and combined to form molecules and particles that the body can utilize every day. For instance, some foods are formed into methyl tags, which are important because they silence genes.


2. Can the diets of parents affect their offspring's epigenome?

Yes, the diets of parents can affect their offsprings epigenome, and this is because whatever nutrients the mother recieves during childbirth are passed down to the child. Say, a mother drinks alcohol. Her child would be harmed because the alcohol would affect genes and brain cells.

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EPIGENETICS & THE HUMAN BRAIN

1. How does Dietary methyl influence gene expression ?

Dietary methyl affects gene expression by stably altering gene expression (turning some genes on and others off).


2. Why do Toxins affect gene methylation?

Toxins can not only poison people, but they can also harm unborn babies. Toxins can change gene methylation by reducing or increasing methyl group amounts. Drugs such as cocaine can give long-term gene damage or changes even.

Tuesday, November 23, 2010

DNA Fingerprinting

Introduction:

1. DNA is unique for everyone. The only exception is if a person has what?
If someone has an identical twin, the DNA is not unique between them.

2. What are DNA fingerprints used for?

DNA fingerprints can be used to find a biological parent or even finding criminals and suspects.


Part 1 “It Takes a Lickin”

3. What “crime” was committed?
Somebody licked Jimmy Sweet's holographic NOVA lollipop.

4. What bodily fluid was removed from the “crime scene” to get DNA?

Saliva was removed to get DNA.

Part 2 “DNA Fingerprinting at the NOVA Lab”


5. What does a restriction enzyme do?
A restriction enzyme cuts DNA at certain parts of the DNA. Where the DNA is cut depends on the codes in both DNA and the enzyme.

6. What is agarose gel?
Agarose gel is a thick, jello- like liquid that is a "molecular strainer", meaning that it will allow small pieces of DNA to move farther and more easily than the longer pieces.

7. What is electrophoresis?
Electrophoresis is the process of moving molecules with an electric current.

8. Smaller fragments of DNA move ____________ than longer strands?
Smaller fragments of DNA move more easily than longer strands.

9. Why do you need to place a nylon membrane over the gel?
You need to place a nylon membrane over the gel because the DNA will transfer to the nylon, allowing an easier representation to work with than the agarose, which is hard to work with.

10. Probes attach themselves to __________
Probes attach themselves to DNA fragments on the nylon membrane.

11. Which chemical in your "virtual lab" is radioactive? The probes are radioactive because they were labeled radioactively so that they can be traced.


12. Sketch your DNA fingerprint.

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13. Based on your DNA fingerprint, who licked the lollipop?

Honey licked the lollipop.


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?

You could go to the DNA Workshop activity, learn more about cell division, DNA replication and protein synthesis, and click on links to learn more about the people who first discovered these processes and the such.

Find an Article about DNA

Go to http://www.thegenesite.com/

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 ____________________________ Author and Date ______________________________________

Summarize what the article was about. Write this in a paragraph format.

NOTE: This site didn't work at the time of my usage, it is just a search site that provides advertisements only.

Wednesday, November 3, 2010

Mitosis

Mitosis Tutorial:
1. Which stage does the following occur:

Chromatin condenses into chromosomes.

Prophase.

Chromosomes align in center of cell.
Metaphase.

Longest part of the cell cycle.
Anaphase.

Nuclear envelope breaks down.
Prometaphase.

Cell is cleaved into two new daughter cells.
Cytokinesis.

Daughter chromosomes arrive at the poles.
Telophase.
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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?
Four chromosomes are visible.

-- How many are in each daughter cell at the end of mitosis?
Four chromosomes are in each daughter cell.

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

-- What happens to the centrioles during mitosis?
The centrioles gravitate towards the poles of the cell during mitosis, and separate the cell.

3 . Identify the stages of these cells:
The first image is of a cell in metaphase.
The second image is of a cell in cytokinesis.
The third image is of a cell in prophase.
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Another Mitosis Animation:

Prophase: The centrioles begin to go towards the cellular poles, and the chromosomes fully form. Also, they spread out.

Metaphase: In metaphase, the spindle fibers attach to the chromosomes and the chromosomes align in the center of the cell.

Telophase: In telophase, the nuclear envelope forms, and chromosomes go towards the poles of the cell, to finally split the cell into two daughter cells.
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Onion Root Tip - Online Activity


Number of Cells:
Interphase: 20
Prophase: 10
Metaphase: 3
Anaphase: 2
Telophase: 1
Total: 36
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Percent of Cells:
Interphase: 55%
Prophase: 28%
Metaphase: 8%
Anaphase: 6%
Telophase: 3%
Total: 100%
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Mitosis in Whitefish and Onion Roots

Whitefish
View 1: Telophase
View 2: Metaphase
View 3: Prophase
View 4: Anaphase

Onion
View 1: Prophase
View 2: Metaphase
View 3: Prophase
View 4: Telophase
View 5: Anaphase