1/31/2010 Blog!

This week in Science we learned more about Meiosis. We learned about this through simulations, research, and discussions. This is important to know because our own cells go through Meiosis.

Dear past Katie,
When thinking about the differences between Mitosis and Meiosis, there are many things to consider. Remember that the stages of Mitosis are Interphase, Prophase, metaphase, anaphase, and telophase.The stages of Meiosis are diploid cell, phophase 1, metaphase 1, anaphase 1, telophase 1, prophase 2, metaphase 2, anaphase 2, telophase 2, and gamete. So, keep in mind that there are more stages in Meiosis and that many of the stage names are the same. There are many differences between the two to keep in mind. For example, in Mitosis, after telophase and cytokinesis Mitosis is complete, but, in Mesiosis, after Telophase 1, there is still much more to do, So, remembering that Meiosis is about twice the length of Mitosis, you can remember that the result of Mitosis is two identical diploid cells and that the result of meiosis is 4 haploid cells. Also, think about how haploid sounds like half, and haploid cells have 50%, or, half, of the DNA. Another key to learning the differences between Mitosis and Meiosis is looking at pictures of corresponding stages of both processes, which is helpful in identiying similarities and differences.
Hope this was helpful!

Something that is helpful in understanding the similarities and differences is viewing simulations of the two processes to grasp a better understanding of the stages, what the stages look like, and what happens in each stage.

1/24/10 Blog!

This week in Science we learned about Meiosis.

We learned about meiosis, or, sexual reproduction, by going online and researching it. We learned that the stages are: Diploid cell;Prophase 1; Metaphase 1; Anaphase1; Telophase 1; Prophase 2; Metaphase 2; Anaphase 2; Telophase 2; and Gamete. We also learned what happens during each stage. Also, we learned Meiosis makes four replicated cells that each have a nucleus, chromosomes, and DNA.

This is important to know because we should know what process takes place in cells that fill our bodies.

1/17/10 Blog

This week in science, we learned about the cell cycle.

We learned that different cells go through the cycle different amounts of times. The cycle consists of:

1. Gap 1-in which the cell grows and makes proteins, interphase takes place
   
2. synthesis
3. Gap 2- in which the cell grows and the DNA replicates(copies)
4. Mitosis- in which each cell receives chromosome copies
   
5. Cytokinesis

Before a cell enters the synthesis stage, it checks if it is big enough and if the environment it is in is suitable. Between Gap 2 and Mitosis, the cell checks if the DNA is replicated, and during mitosis, the cell checks to make sure the chromosomes are alligned. Mitosis takes place in a very short amount of time. Cells spend 50% of their time in interphase, 27% of their time in prophase, 8% of their time in metaphase, 5% of their time in anapahse, and 2% of their time in telophase.

Many different things happen in mitosis, like: During anaphase, sister chromatids move apart; in Telophase, a new nuclear membrane forms around chromosomes and the cell's cytoplasm is divided; In, Prophase, the spindle is formed and the nuclear membrane and nucleolis begin to fade from view. Many things happen in Mitosis!

Also, by labeling pictures, we learned about identifying what stages of mitosis cells are in.

This is all very important to know because, cells are in and all around us, and it is important for us to know their life cycle.

This week in science, we learned about reproduction.

To learn about reproduction, our class made a table. For organism reproduction and cell reproduction, we put:

• some use sperm and egg to reproduce
• others split in two
• makes a copy of organelles
• replicates(copies)
• before splitting, DNA must double in size

Under the category of: Sex vs. Reproduction, we wrote

• For Sex:
• 50% sperm cell
• 50% egg cell
• cell delivery service
  
• does not necessarily end with offspring

For Reproduction:

• Sperm and egg join together
• fertilize

This is important to know because reproduction is constantly going on.

To further explore reproducing cells, we found out the 5 stages of Mitosis and tried to find cells during those stages in a microscope while looking at an onion root tip slide.