Tuesday, January 18, 2011

Cloning!! And More Meiosis

I have to say, I love this Biology Unit. I love learning about the mechanics of the machine that is our body. It's interesting (to me at least) to know that meiosis is what starts the baby making process! Learning about the 18 Ways to Make a Baby was really neat, and one of the ways was cloning.

Introducing, the amazing Cloning Charlie! He uses his super hero skills to divide and conquer evil. Unlike the process that goes on in cloning animals, Charlie's super powers could be compared to the production of sperm or plant mitosis.

 So, what goes into the animal cloning process? I'm not quite sure myself, but let's look at how a mouse is cloned and try and determine what in the heck is going on.

1. Meiosis here. That is how the regular splitting of cells occurs. After a woman's egg becomes fertilized it moves onto meiosis 2, the fetic and embryonic stages. But with cloning, you are going to have to exact same DNA as the creature you took the DNA from.  From here on is the recipe for cloning.


1 Mouse Somatic Cell
1 Mouse Egg
1 Surrogate Mouse
1 Dividing Agent (mouse sperm)

1. Extract a somatic cell from the 1st mouse. Harvest the egg from the 2nd.
2. Remove the nucleus from the egg cell. Replace with the nucleus from the somatic cell.
3. Fertilize the new egg cell.
4. Implant the egg into the surrogate mouse.
5. Hurray for babies!

Friday, January 14, 2011

A Blog About Meiosis

I think new borns are extremely weird looking. Like little aliens. At an embryonic 12 weeks, they are even more frightening. I once told my friend that I thought at that point in the gestation period they looked like predators. Like Alien Vs. Predator. They frighten me. It's hard to believe that at one point that weird little red thing was once just an even littler gamete. Beginning as gametes, then they're a zygote with a diploid, then it turns to a haploid cell. It's like mitosis, but this creates what become little kids who become adults who make more little kids. So I was curious and decided to research how to make a baby!

Step 1 (AKA Prophase 1): A diploid cell splits, making four haploid daughter cells (this is what creates genetic diversity). The paired chromosomes are called chiasmata, which are caused by genetic recombination.

Step 2 (Prometaphase 1): One kinetochore (the protein structure where chromosomes attach) forms for each chromosome and the chromosomes begin to move.

Step 3 (Metaphase 1): The two chromosomes, now bivalents, line up at the metaphase plate. At this point there is a 50/50 chance that  the daughter cells will get either the mother or father's feature.

Step 4 (Anaphase 1): The daughter cells become haploid cells after chiasmata separate (chiasmata is where the cells exchange DNA).

Step 5 (Telophase 1): The cell either reforms or starts meiosis 2.

Step 6 (Cytokinesis): This is where the two daughter cells form.

There we have it, meiosis! This process keeps happening in men, but in women it doesn't continue until an egg is fertilized. Which will be continued in a separate blog on.... meiosis II.... DUN DUN DUN!

Monday, January 10, 2011

Stem Cell Research

Important Terms:

Cell-based therapies: stems cells are induced to differentiate into a specific cell type.
Differentiation: where a unspecialized cell acquires the specialized features of a specific cell.
Embryonic stem cell line: embryonic stem cells that allow proliferation without differentiation for months to years.
Proliferation: the expansion of the number of cells from two identical daughter cells.
Plasticity: ability to be different.
Pluripotent: Having the ability to give rise to all the various cells types of the body.

Answer the following questions:

1. What are the unique properties of all stem cells?  Explain in your own words what each property means.
Stem cells are able to proliferate; splitting and reuniting, can become any cell, and can differentiate; can become a specific type of cell.

2. What are the two main kinds of stem cells used by researchers?  What are the major differences between the two types in terms of their sources and usefulness to researchers?  Give examples for each type of stem cell.
The two main kinds of stem cells used by researchers are embryonic cells and adult stem cells.

3. List some of the diseases that scientists think may be treated using stem cell research and suggest how stem cells might be used to treat each disease.
Scientists think that stem cells may be used to cure diseases such as cancer and birth defects.

4. What are the necessary characteristics that laboratory-manipulated stem cells will need to have in order to be successfully used in cell-based therapies?
The stem cells need to be unspecialized. 

Friday, January 7, 2011

What I'm Glad I Know Now That I Didn't Know Before (a break from Biology :))


Let me start by asking, what are you going to do when you grow up? Are you going to move to Zambia and ride giraffes? Or don a space suit and rocket to the moon? I don't know the answer to that question, and neither do you, most probably. In Paul Graham's speech, he reassures his audience that, yes, you can have absolutely NO CLUE what you want to do when you get to college! Now, I've been told this over and over again by multiple adult people (and they should know, shouldn't they?), but it was reassuring to see it written, or typed, as it was here. This article took a stick and jammed it into my brain and played around in my mind. I found myself immensely relieved that I still have time. And slightly smug, knowing this tiny gem of wisdom. Something Mr. Graham wrote really hit me. "If I were back in high school and someone asked about my plans, I'd say that my first priority was to learn what the options were." He then goes on to say there's no rush to figure out what you want to do for the rest of your life. I agree. If you're going to do something, you should be able to do it right, and enjoy it every time you do it. I will conclude by asking another question. Are you going to worry about what you're going to do when you grow up? Or are you going to relax and find a perfect medium?

Onion Root Cell

Begin by reading the description of the five major cell phases. You will need to keep this information in mind during the activity.

Make a copy of the data sheet that appears on the second page. You will need it to answer the questions.

Proceed through the activity, identifying the phase for each cell you are shown. Pay attention to the hints if you misidentify a cell at first.

Number of Cells
Percent of Cells

When you have completed the activity, answer the following questions:

1. What percent of cells were in interphase?
55.5% were in Interphase.

2. What percent were in mitosis?
100% were in mitosis.

3. Which phase of mitosis takes the longest?
Metaphase takes the longest.

4. During which stage is the nucleolus visible as a dark spot?
In Interphase, the nucleolus is visible as a dark spot.

5. How can you recognize a cell in metaphase?
You can recognize a cell in metaphase by the “squiggles”.

Wednesday, January 5, 2011

Mitosis and Me

After taking the pre-test for the Cell Cycle, I realized that I really need to work harder this Semester. So I too a trip to visit Google, my best friend next to freetranslation.com.

1. Definition for the Cell Cycle: The process in which a cell grows and divides. Some cells take 24 hours to  go through the cell cycle (animal cells) and some do not divide at all (neurons).
Compliments of:  http://www.wisegeek.com/what-is-the-cell-cycle.htm

2. How it happens and what follows.
Interphase: G1, S, G2.
1. G1: grows in size and manufactures more
2. S (Synthesis): where the cell replicates the cell's DNA, only one copy is made.
3. G2: the cell continues to grow and produces a number of molecules
4. M: the cell's DNA condenses into chromosomes and are then are sorted into an even amount.
     They are then split into two different cells.
  • a) Interphase: The very end of the Cell Cycle, where the cell becomes two separate cells. 
  • b) Prophase: The Beginning of Mitosis: the centrosomes move towards the opposite poles of the cell. The sister chomotids become more visible as they condense. 
  • c) Metaphase: The chromatids are lined up between.
  • d) Anaphase: The chromotids begin to separate and become chromosomes and move towards the ends of the poles.  
  • e) Telophase: The chromosomes arrive at the poles, finally, and begin to grow their own nuclear membranes.
  • f) Cytokinesis: A furrow is created in the parent cell and eventually "pinches" the two new cells apart. 
And this is how cells reproduce!