Onion Tip

http://bio.rutgers.edu/~gb101/lab2_mitosis/index2.html 



Introduction: Find out the difference between Cytokinesis and Mitosis.  How do they go together in order to complete the cell division process?  


Part 1: 
Can you find dividing cells in the onion root tip?
Yes, we can see cells in every phase of the cell cycle.

What differences can you see when you compare the nucleus of a dividing cell with that of a 
non-dividing cell? 
In a non-dividing cell, we can clearly see the nucleus whereas in other stages we see it less clearly or we can't see it at all


Part 2: View a video of mitosis in an animal cell. 

<iframe width="640" height="360" src="http://www.youtube.com/embed/cvlpmmvB_m4?feature=player_embedded" frameborder="0" allowfullscreen></iframe>

Part 3: Identify at least one cell in each of the stages of division summarized in the review. Place the cursor over a dividing cell and click once. Identify the stage of division. When you have identified at least one cell in each stage, proceed to the next section.

Part 4: See what differences you can detect between the division of an animal cell and a plant cell.  


 

Is Dominance Always Dominant?

In class we did an online lab about dominance. Here is the link:
http://www2.edc.org/weblabs/IncompleteDom/IncompleteDominanceMenu.html


After crossing many different pea plants, snapdragons and lentils, I realized that there are three types of dominance.


The first type is dominance. This is when the dominant allele is completely dominant over the recessive allele. For example pea plants. We can see the dominant gene in color. There are two colors of pea plants; purple and white. The purple is dominant over the white. If one parent is purebred purple and the other purebred white then 100% of the offspring will be purple but will carry the gene for the white color. Mendel used pea plants in his experiments and this is how he found out how some genes were dominant over others.

The second type is Incomplete Dominance. This is when alleles aren't dominant over each other. For example Snapdragons. If one parent is purebred red and the other purebred white, the offspring will be pink. As if both colors blended together to form a new color.

The third type is Co-Dominance. This is when both traits are expressed. For example Lentils. If one parent is purebred spotted and the other purebred dotted, the offspring will be spotted AND dotted. As if they weren't able to decide which one should b dominant so both are equally expressed.

Guilty or Innocent?

1) Based on your findings, were any of the suspects present at the crime scene?  Support your conclusion with specific evidence.  


Suspect 4 was present at the crime scene because the DNA sample matches. We know this because the lines are exactly the same as the sample collected on the crime scene. 


2) Why do people's DNA patterns differ so greatly?


People's DNA differ so greatly because no one has the same DNA. DNA is the instruction manual to how our body works, how we look like, how we act and also the disease and traits we carry. No one is the same, therefore, no one's DNA is exactly the same.    


3) How would your conclusions be affected if you learned that the suspect whose DNA matched the evidence had an identical twin? 


Even though they are identical twins, since no one has the same DNA, I think they each have a very slight difference. It would be a shame if the investigators read the DNA wrong and accused the wrong twin.  


4) Suppose you are a defense lawyer. DNA evidence indicates that the bloodstain at the scene of a crime belongs to your client.  Do you think this DNA evidence should be enough to convict your client?  


This means that my client was at the place of the murder but does not necessarily mean that he is the murderer. The murderer could have threatened him with a knife, cut him and there would be a blood stain. Investigators can look into the DNA and my client may be the murderer. But there is also a chance that he isn't. Sometimes, DNA is not enough to prove someone guilty. 

Current Event

Is it possible to die of boredom? Well, in a way, yes. 

"According to the Center for Boredom, Interest and Entertainment, 26 percent of respondents in a 1952 survey claimed that boredom was a serious problem in their lives. By 1978, the number had risen up to 38 percent". Apparently. the more free time we have the more chances we have to get bored. Some people use the excuse of being bored to do something new or interesting. On the other hand, others are not so positive and use their boredom as an excuse for destructive behavior (drugs, drinking, excessive gambling...). In extreme cases, boredom can sometimes lead to suicide. In addition, a study shows that people who are often bored are more prone to heart diseases. "Those who had reported being bored at work were 2.5 times more likely to have died of a heart disease. To put this in perspective, people who smoke are between two and four times more likely than nonsmokers to develop heart disease".


I find this interesting that someone actually looked into whether or not you can die from boredom :) If someone smokes AND has a very boring life, he actually has a very high risk of developing a heart disease. 


link: http://curiosity.discovery.com/question/can-you-really-die-boredom

Karyotyping Activity

Karyotyping Activity: http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html


Patient A: 


1) What notation would you use to characterize Patient A's karyotype?
47, XX/XY, +21


2) What diagnosis would you give Patient A?
Patient A has Down Syndrom. He has Trisomy 21, in other words, he has an extra chromosome 21.


Patient B:


1) What notation would you use to characterize Patient A's karyotype?
47, XXY


2) What diagnosis would you give Patient A?
Patient B has Klinefelter's Syndrome. He has one extra sex chromosome.


Patient C:


1) What notation would you use to characterize Patient A's karyotype?
47, XX/XY, +13


2) What diagnosis would you give Patient A?
Patient C has Trisomy 13 Syndrome. He has an extra chromosome 13.