Julia

=What is similar and different about the cell cycle and meiosis?=

the smallest structural and functional unit of an organism
In a cell, there are many kinds of substances in the cell that helps materials or substances stay protected, move from one place to another or break down food particles.
 * Example 1:** Plants and animal cells have a membrane called the cell membrane, this helps protect the cell and controls what goes in and out of the cell. Plants also have a larger layer outside
 * Example 2:** Plants and animal cells also have a passageway inside a cell called the Endoplasmic Reticulum, this helps carry materials or substances from one part of the cell to another.


 * [[image:38%20mitotis%20phases.jpeg width="441" height="371"]] || [[image:23414_cellcycle_eng.jpeg width="352" height="499"]] ||

**How does the Cell Cycle work?**
There are three steps in order for the cells to split into two different other cells. 1. The first stage is the **Interphase**. The Interphase is the period of time before the cells divide and form more. During that time, the cells start to grow larger and larger. As It grows larger, it makes a copy of the cell's DNA while it is preparing to divide into two cells. 2. Once the interphase is complete, the second stage of the cell cycle starts and it is called **Mitosis**. Mitosis is a stage during which the nucleus of the cell divide into two new nuclei. During mitosis, one of the two copies of DNA is distributed into each of the daughter cells. 3. After the DNA is distributed into each daughter cell, the third stage called **Cytokinesis** begins. First the cell membrane pinches in around the middle of the cell and the cell splits in two. Each daughter ends up in an identical set of chromosomes that were in the large one and the chromosomes start to grow again.

**How does Meiosis Work?**
There are four steps in order for more of the sex cells to produce. 1. Before Meiosis begins, all the chromosomes in the parent cell is copied and that is called a **chromatid**. When they are replicated, the centromeres help hold the two chromatids together. 2. The pairs of chromosomes line up face to face in the middle of the cell. Then the pairs separated to the opposite sides of the cell when the cell grew larger. Two cells form, each with half the number of chromosomes, but each chromosome still has two chromatids. This step is called **Meiosis Ⅰ**. 3. Then again, the chromosomes with their two chromatids move to the center of the cells. The centromeres split in half and the chromatids separate. The chromatids with a single chromosome move to opposite ends of the cell. This step is called **Meiosis Ⅱ**. 4. Finally the four sex cells have been produced and each cell as only half of the number of chromosomes their parent cell had before meiosis. Each cell ends up with one chromatid. This is the end of Meiosis.
 * Example:** A human has 46 chromosomes and when dad's sperm shares 23 and mom's egg shares 23, the baby is born with 46 chromosomes.

Similarities:

 * They are both related to growing and developing.
 * The cells separate during this cycle.
 * The cells progress and get larger during the cycle.
 * They are both related to producing replicants.
 * The chromosomes separating help the cells grow in both ways.
 * They both go through a process before dividing up.
 * Before beginning the cell cycle or Meiosis, there is a step where the cells have to get ready to separate.

Differences:

 * Cell Cycle
 * The cells are increased by replicating the DNA.
 * The cell cycle is what you can see in real life. Ex: Pig growing up from a baby.
 * The nucleus divides into two new nuclei when the cells are dividing.
 * One copy of the DNA is given to each of the two daughter cells
 * The cell cycle is a broader cycle than meiosis.
 * The cell cycle has steps that are repeated once
 * The cell cycle goes in a circle
 * The eukaryatic cell divides the chromosomes into two identical sets
 * Describes the various stages through which a dividing cell passes
 * Meiosis
 * The cells are increased by separating the chromatids and making cells with less chromatids.
 * Meiosis is the cycle that is happening inside your body.
 * Two pairs of chromatids separate when the cells are dividing.
 * The resulting sex cells have only half as many chromosomes as the other cells in the organism.
 * Meiosis is what is happening inside the body while the cell cycle is occurring.
 * Meiosis has steps that are repeated twice (except the first step)
 * Meiosis goes in a straight line after all 4 sex cells are formed.
 * The number of chromosomes are divided in half



media type="youtube" key="yrMTrH2qvfo" height="315" width="420"

Vocabulary:

 * Daughter Cells:** The new cells that form when a cell is fully grown.
 * Replication:** The action of copying or reproducing the exact copy.
 * Chromosomes:** Threadlike chromatin in the nucleus condenses to for double-rod structures. Each chromosome has two rods because the cell's DNA is replicated.
 * Nucleus:** The brain of the atom, the central circular sphere in the middle.
 * Nuclei:** more than one nucleus
 * Sex Cells:** Sperms and Eggs

Sources:

 * Prentice Hall (Science Explorer)-** pg. 56-59, 94-95, 113-115
 * University of Leicester-** http://www2.le.ac.uk/departments/genetics/vgec/education/post18/topics/cellcycle-mitosis-meiosis
 * University of Leeds-** http://histology.leeds.ac.uk/cell/meiosis.php

Pictures:
Back to Home
 * Chinese Wikipedia-** http://zh.wikipedia.org/zh/File:Plant_cell_structure.png
 * Albinoburmese-** http://www.albinoburmese.com/genetics.htm
 * Youtube-** http://www.youtube.com/watch?v=yrMTrH2qvfo&feature=fvst