Genetic Variety Blog.

Genetic Variety means that each new cell is different from each the parents. It is not exactly 1/2 of Mom and 1/2 Dad. Crossing over occurs, which means that the chromatids become varieted and each one has a little bit of Mom and a little bit of Dad. Here is a picture of crossing over :

As you can see, each gamete has a different mix. Nothing is the same. Once sexual reproduction occurs, these will mix. Whichever gamete ends up becoming fertilized has a different amount of the DNA from each parent.

The Reebops do the same thing too. They also have to got through sexual reproduction to produce their child. Each new child isn't exactly like the parents. Some are mostly like one parent (because four different traits are possible.... Punnett Square.) while others have a different mix. My Reebops have maybe only one of the grandparents traits. Some have almost all of the one of the parents traits. This shows variety from each cell. This is actually genetic variety, because there is an assortment of different traits and genes. My second Reebop could look nothing like it's parents. Maybe it is because it got some of the receesive traits from the parents. Here is an example of what could happen:

Parents:

Child:

You can see that even though the parents are green and brown, it doesn't neccesarily mean that the child has to be green or brown.

Genetic variety is when the children are different. Remember that genetic variety is just like it's name..... it's differences in the traits.

Thanks for reading.

If I could go back in time and help myself about something, it would be Punnett Squares and Gregor Mendel. I found this very confusing before and there are some things I would like to clarify with my past self.

First off, I would tell her that Punnett Squares are not as difficult as I though they were. To clarify even more, I would tell her to think of plotting points on graph paper to find which points go in which quadrant of the graph.Then, just match up the alleles above the first square and next to the first square to have my alleles that would be possible for my offspring. I would also tell my past self to just think about how things would match up in the Punnett Square. I would say that if the two parents are homozygous dominant for something, the child can't be homoszygouse recessive, because none of the alleles would match up in a Punnett Square that would make that true.

Also, I would tell myself that Mendel was breeding these pea plants by taking pollen from each plant and mixing them to make different offspring. Pollen is gametes, so this is kind of like sexual reproduction. I did not understand what Mendel was doing when I first read it in out books, but now I understand Mendell's purpose for breeding these pea plants. He was curious of what the outcome of the offspring would be with all of the different combinations of pea plant parents.

An experiment that really helped me realize this was the pea soup experiment on the computer. Looking at the different alleles and traits of each pea really helped me understand the concept of genetics and the breeding that I mentioned before.

Below is an example of one of the possibilities of breeding two peas:

Week of Science.

If I could travel back in time and talk to myself about the process of meiosis, I would tell myself to remember that each cell gets 50% of the DNA. Also, that the result meiosis is four cells. Another point would be that the cells cross over. The result or meiosis are sex cells, or gametes. Examples of gametes are:

-Egg

-Sperm

-Pollen (In plants)

Lastly, cells cross over in meiosis. They would look like this open up:

The pictures on the bottom of this is meiosis itself. At the end, you can see that the cells are almost into four new ones, but not quite.

If someone had told me that the cells cross over and that each cell gets 50% or the DNA at the end, it really would have helped me. I would have realized that this makes sense because 50% is from Mom and 50% is from Dad. Each cell has 50%, so when they come together, they would make 100%.

The simulation that Mr. Finley showed us on Friday would've really helped me because it showed the similarities between Meiosis and Mitosis. This really helped because it is easier to compare something to another thing I was already quite familiar with. (Mitosis.)

Meiosis is a very interesting (but quite difficult) subject.

This Week in Science.

We started off this week with Martin Luther King Jr. Day, so we didn't have school on Monday. On Tuesday, we reviewed for our quiz we were going to have the next day. We remembered that DNA is a double helix. Each helix is one sugar backbone. We reviewed what chromatins, chromatids and and chromosomes look like. We thought back to when we learned that in Early Prophase, the spindle fibers start to form. The spindle fibers are what connect to the kineticore during Prometaphase. They straighten the chromosomes out and pull them apart towards opposite poles of the cell.

Also in Promataphase, the DNA starts winding up and the centrioles become visible. The last thing we reviewed that day was what autosomes were. Autosomes are:

Autosomes- All of the chromosomes that aren't sex chromosomes.

We then had our quiz about Mitosis.

This week we also started learning about Meiosis. Meiosis is when a cell reproduces into four new cells, which is different from Mitosis. Mitosis is when it splits into two. The phases in Meiosis are:

1. Prophase I

2. Metaphase I

3. Anaphase I

4. Telophase I

5. Prophase II

6. Metaphase II

7. Anaphase II

8. Telophase II

There are also Diploid Cell and Gamete, but these aren't a part of part of Meiosis.

Here is what happens in each phase:

Diploid- Chromosomes produce sister chromatids.

Prophase I- Dyad pairs allign to tetrads.

Metaphase I- Spindle fibers attatch to the tetrads at the kinetocore, the spindle fibers move the tetrads to the equator.

Anaphase I- Sister chromosomes move to the opposite sides of the cell.

Telophase I- A cleavage furrow forms to begin cytokinesis. They're soon going to form into daughter cells.

Prophase II- Spindle formation begins and centrosomes begin to move to the opposite sides of the cell.

Metaphase II- Spindle fibers align the chromosomes to the center.

Anaphase II- Chromatids seperate and begin moving to opposite sides.

Telophase II- Cleavage furrow forms to begin cytokinesis.

Gamete- Nuclear envelope form. Meiosis has produced four daughter cells.

In meiosis, we make sex cells which are also called gametes.

Lastly, this week we looked at autosomes and their different sizes. We learned that there are two. One is from Mom and one is from Dad. We learned that Mom's have two X chromosomes and Dad's have one Y and one X.

In karyotypes, you can tell the gender of the baby, if it has Down Syndrome and the amount of chromosomes it has.

That is what I learned in science this week.

This week, our class started learning further information about Mitosis, a subject we had just touched bases on last week in science. Mitosis is the splitting of the nucleus. We started off the week learning about the different kinds of DNA structures and the different kinds of DNA organizations.

We learned that chromatins are unravelled, unorganized DNA. It is kinds of like a ball of yarn.

Next, we learned that chromosomes are wrapped up and very organized DNA. Instead of a ball of yarn, a chromosome is like a neatly and smoothly wrapped spool of yarn, instead of a ball.

During mitosis, DNA replicates. This is when the DNA copies itself and makes double the amount of DNA. There are pre-replication chromatids, which are only one line. There are also post-replication chromatids, which look like X's. They are two of the pre-replication chromatids, connected by a cell plate.

We then learned that during a big chunk of the cell's life, it is in interphase. This phase is also named the resting phase because from the outside, it doesn't look like the cell is doing much. On the contrary, inside the nucleus, the DNA is preparing for mitosis to begin.

We also learned that centrosomes are organized cells.

We also took the following notes:

• How many times the cell goes through the lifecycle differs, depending on the type of cell and it's structure and functions.
• Interphase is part of the lifecycle.
• Most of the cell cycle is interphase.
• Mitosis is the splitting of the nucleus.
• Some scientists say that cytokenesis is part of mitosis, but others beg to differ.
• Cytokenesis is the process of the cytoplasm splitting, hence the cytokenesis.
• Synthesize-Replicate.
• Centrioles- Create the spindle fibers.

The order of phases in mitosis (if we include interphase and cytokenesis):

1. Interphase

2. Prophase

3. Metaphase

4. Anaphase

5. Telophase

6. Cytokenesis

That is what I learned in science this week.

In the week of 1/3-1/8

Green is definitions.

Blue is bullet points.

Red is everything else.

On Monday, Tuesday part of Wednesday of this week, people in our class presented their fermentation, protein synthesis, respiration and photosynthesis projects. Therefore, I cannot elaborate on anything I learned because I unfortunately didn't take notes of these presentations, though they were very good and informative.

This week, we started learning about Reproduction. I learned that:

Reproduction- The process of fertilization.

Fertilization- The process of the egg (ova) and the sperm joining.

We also made a chart about the following subjects:

• Organism Reproduction
• Cell Reproduction
• Sex vs. Reproduction

I unfortunately cannot make a chart, but I will clearly state the facts I know about each topic:

Organism Reproduction:

• In some, there is a sperm and egg to reproduce.
• In others, they split into two.
• The ones that split in two, they make a copy of the organelle and then replicate or copy the DNA.

Cell Reproduction:

• Before splitting, the cells must double in size.

Sex vs. Reproduction.

• Sex is like a cell delivery system.
• The sperm and egg join in sex.
• In both, they don't necessarily end up with a baby popping out.
• There is 50% sperm and 50% egg.

The next day, we talked more about reproduction.

We were asked:

Why do cells reproduce?

As a class, we came up with the two answers to this question.

We said:

• They reproduce to replace old and dead skin cells.
• They reproduce because we are growing.

We also learned that in plants, the roots are always reproducing.

We then started a lab about onion root tip cells and what they look like in the stages of reproduction. We thought of the following things to look for:

• Cells get bigger (larger cells)
• More DNA (bigger nucleus to get ready to accomadate for a new cell)
• More clumps of DNA (chromosomes.)
• More organelles.
• Splitting cells.

http://www.microscopy-uk.org.uk/micropolitan/botany/onion_root_mitosis.jpg

To see a picture of an onion root tip, click on the link above.

We drew pictures of the different looking onion root tips and what stages of reproduction we thought they were in.

For homework that night, we had to look up mitosis. Mitosis is:

Mitosis- When the nucleus divides into two nuclei and is part of a larger life cycle of life. It is in Eukaryotic cells. The Prokaryotic cell term for mitosis is Bianary Fission. The result is two identical cells.

On Friday, we looked at a stimulation and took notes about it, and we looked again at an onion root tip under a microscope.

I found notes about the following stages:

Interphase- When the DNA replicates and the centrioles divide.

Prophase- The first stage in mitosis (see above) when the nuclear envelope breaks down and strands of DNA form into chromosomes.

Prometaphase- When the nuclear envelope breaks down so there is no more recognizable nucleus.

Metaphase- Tension applied to the spindle fibers aligns and all of the chromosomes in one plane at the center of the cell.

Anaphase- When the spindle fibers shorten and the chromosomes are pulled apart.

Telophase- When the chromosomes reach the opposite poles of the dividing cell and the nuclei daughter cells form.

That is what I learned in science this week.

In Science

On Monday, we saw a simulation about how we live on a street in a city in a state in a country in the earth in the solar system and so on. This is is an analogy for DNA which is in the nucleus which is in the cell which makes up organs which make up organ systems which make up the organism which make up the population.

From this, we learned everything is part of something bigger.

The next day, we learned about codons and furthermore about protein synthesis.

Codons- Triplet nucleotides (bases) that are given for amino acids. These are recognized by the Transfer RNA, or tRNA. They are a part of messenger RNA.

We saw another simulation about protein synthesis that day too.

I learned:

-Ribosomes wait for the RNA, and then the ribosomes pick up the RNA.

Lysosome- Gets the organelles that don't work, out.

Golgi Apparatus- Actually gets it out.

Gets RNA from nucleus, once the ribosome "eats" it, he makes the protein.

The next day, we learned the following things:

- Organisms have to be able to live on their own.

- The cell membrane is like a door because it lets things in and out.

- Molecules contain protein, carbohydrates, lipids and nucleic acids.

- Lipids are fats.

- DNA are the most important nucleic acids.

- The cell membrane is a thin film over the cell.

- Animal cells don't have chloroplasts.

- Prokaryotic cells usual just contain a cell wall, cell membrane, cytoplasm and DNA.

The next day, we were introduced to the new project we were going to be doing about either respiration, photosynthesis, fermentation or protein synthesis. I chose to do mine on protein synthesis, and made a poster. For homework that night, we had to make up an analogy for a cell and it's organelles. Here is what I wrote:

A cell is like a library.

The books are like the nucleus- It holds all of the information, like the books who have information.

The walls are like the cell wall- Helps protect the cell and gives the cell structure, like the walls of the library keep the roof off and keep it isolated from the outside.

The doors are like the cell membrane- They let things in and out, like the door lets people in and out.

The Dewey Decimal System is like the ribosomes- They put the books and place and crack the code for where each book should go, like the ribosomes sort RNA.

The Librarian is like the mitochondria- Just like the librarian does for the library, it gives it energy or knowledge and effort for everything to be in the right place.

The Author is like the Rough Endoplasmic Reticulum- It makes things for the cell to use, like the author makes the books to read.

The Editor is like the Smooth Endoplasmic Reticulum- It takes the bad things out of the body, like the editor does to the books.

We then learned a little bit of further information about fermentation.

Fermentation takes place in the cytoplasm. It makes food such as bread and cheese using yeast. Fermentation is important because it allows cells to meet their energy needs when oxygen is not present.

On Friday, we read from the books and worked on our projects, so I don't have any noted about that.

That is what I learned about this week in science.