3.24c Mitosis

Understand that division of a diploid cell by mitosis produces two cells which contain identical sets of chromosomes.

Stages of mitosis
(a) Nucleus of a cell contains the chromosomes.
(b) During the Inter-phase, the chromosomes are copied. Process: DNA replication Result: 2 copies of chromosomes.
(c) Prophase

1. The break down of the nuclear membrane is the first sign of a cell that is entering the process of cell division + mitosis.

2. Chromosomes become visible as a "pair of chromotids" after the membrane breaks down.




3. Metaphase: Cell divsion carries on, and spindles (fibres) form at opposite "poles" of the cell.


4. Anaphase: The chromotids  line up along the center line and begin to be pulled apart by fibers.

5. Telophase:  The nucleus reforms around the chromosomes at each end of the cell resulting in two nuclies.

3.24b Mitosis

Understand that division of a diploid cell by mitosis produces two cells which contain identical sets of chromosomes.

Interphase Cycle

1. Parent cell.
2. Chromosomes make identical copies of themselves.
3. They line up along the center.
4. They move apart.
5. Two daughter cells form with identical chromosomes to the parent cell.
   This is called DNA replication.
   
   What holds the 2 resulting copies together is the "centromere." It is located in the middle of the chromosomes.
   When like this, they are referred a "pair of chromotids."

3.24a Mitosis

Understand that division of a diploid cell by mitosis produces two cells which contain identical sets of chromosomes.

1. Mitosis =  the type of cell division that leads to growth or repair.
2. Number of chromosomes in the nucleus is called the Diploid number.
3. Process: when a cell divides by Mitosis  (a) two new cells form (b) each cell is identical.
4. Identical with (a) same number of chromosomes (b) same set of chromosomes.

3.16 DNA & Genetic Infomation

Describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thvmine (T) and cvosine (C) with guanine (G)



1.  In the chromosome, we find 100's of genes. Looking at one position on the chromosome called the gene loci, we find a double helix, in which is parallel.

2. Looking closer into the double helix, there are two strands holding it together. They are called "sugar phospate-backbone." In the middle we find a group of molecules called basis, and there are four "adenine (A) with thvmine (T) and cvosine (C) with guanine (G)"
3. The basis are holding together the two helix's, they do this by being paired up between 4 bases called: adenine (A) with thvmine (T) and cvosine (C) with guanine (G).
4. The order of the basis is always the same. But is different to each side. The order, is what makes up the GENE.
A
C
T
G
A
A
C
C
A
G
5.

question: what makes up the protein?