January 29, 2010

Jenni~

Since you have been having a bit of trouble about the differences between mitosis and meiosis, I'm here to talk to you about it.

The first major difference is where these processes take place. Mitosis takes place in cells that have a nucleus(cheek cell) while meiosis takes place in all the sex cells (sperm, egg cells). Next, mitosis only produces two daughter cells while meiosis produces four daughter cells. This happens because first, mitosis happens(two daughter cells) and then the cell doubles (four daughter cells). The difference in daughter cells is called diploid(2) and haploid(4).

One experiment you could do that might help you is look at this simulation. It shows the differences and similarities step-by-step in this process. Here is the attached link: http://www.pbs.org/wgbh/nova/miracle/divide.html (you have to click on the button on the right). This really helped me understand everything that was happening too.
Hope this helped,
Jenni from the Future

Week Fifteen of Blogging

This week we started to learn about meiosis. This is when organisms sexually reproduce. It is kind of like mitosis because they have the same phases. They only difference is the cell goes through twice the phase.
Mitosis: nucleus division, two daughter cells
Meiosis: sex cell division, four daughter cells
Similarities: cell division, DNA replication
We did an online simulkation to help us learn about meiosis and looked up some words we don't understand.

Week Fourteen

Cell Cycle

Key Points of the Week:

+ Depending on the cell size, it might reproduce cells a lot or very few times.

+ Interphase and Mitosis are both part of the cell life cycle

G= growing phases or checkpoints

Mitosis Requirements:

-- big enough

-- right enviorment

-- chromosomes must be lined up

Vocabulary:

+ centreols= Creates spindle fibers

+ chromatin= unraveled DNA

+ chromatid= chromosome in pairs

Week Thirteen (of Blogging)

Reproduction Unit
Onion Root Tip Experiment: Preperation
Why do cells reproduce?
-- repair
-- replace dead cells
-- we are growing
What do we expect to see of REPRODUCTION?
-- larger cells
-- more DNA clumps --> chromosone
-- bigger nuclei
-- more organelles
-- splitting cells
Onion Root Tip Experiment: What Happened
-- When we looked under the microscope, we saw many different cells.
+ about to split

+ lots of DNA strands
+ no nucleus ???
+ big nucleus
MITOSIS: When the eukaryotic cell seperates the chromosone and DNA intoo two identical sets.
Phases:
1. Interphase
2. Prophase
3. Prometaphase
4. Metaphase
5. Anaphase
6. Telaphase
7. Cytokinesis