3.24a Mitosis

• Mitosis is a type of cell division that leads to growth and repair.
• The amount of chromosomes in a nucleus is called the diploid numbers.
• When a cell is divided by mitosis each cell is identical and two new cells are formed.
• Growth occurs by increase in the number of cells. 
• All humans have 46 (2n) amount of chromosomes. 

3.24b Mitosis

• Chromosomes make identical copies of themselves. 
• Two daughter cells form with the identical chromosomes and the parent cells. 
• When this happens it is DNA replication.
• What hold the DNA together is something called the centromere which is located in the middle of the chromosome.
• When this occurs they are know as a pair of chromotids.

3.24c Mitosis

• When a cell first breaks down it shows that it is entering the process of mitosis and cell division.
• Chromosomes become visible as "chromotids" in a pair after the breakdown of the membrane.
• As cell division carries on fibres form and each end of the cells.
• Chromotids line up in the middle of the cell and are pulled apart by fibres.
• The nucleus forms around the chromosomes at each end causing two nuclies.  

3.16 DNA and Genetic information

• One chromosome contains thousands of genes.
• There are 4 kinds of bases called: Adenine, Guanine, Cytosine and Thymine.
• They are found in DNA in the pairs: Thymine-Adenine and Guanine-Cytosine. 
• When you magnify one gene you can see a double helix which appear parallel.
• Genes contain an organized structure of bases in this order: ATCGAACCAG.

Question: Why do double helix's appear in parallel shape?

3.15 Genes

• Genes are located in the nucleus.
• A double helix shaped gene carries information of the characteristic of the organism.
• Information of the gene is passed to the cytoplasm.
• After passing into the cytoplasm the gene is then turned into a protein. 
• Protein controls the characteristic of the gene.

Question: Does that amount of genes you have change your gender?

3.14 Chromosomes

• A chromosome is the genetic information inside a cell. 
• Genes control the production of protein which controls a characteristic.  
• Chromosomes have a DNA that forms a shape which is called a double helix. 
• Each different species have different amount of chromosomes. 
• Chromosomes operate in pairs which are based on length. 

Question: What is the organized structure of a chromosome? 

3.1 Sexual and Asexual Reproduction

• Organisms that have sexual reproduction show sexes that is when they can be identified as a male or female.  
• There are tho different type of genders which are males and females.
• Males have sperm and females have eggs.
• Fertilization is the process of fertilizing an egg of a female animal or a plant involving the fusion of male and female gametes to form a zygote. 
• All humans are different, physically and mentally and don't look alike unless they are un identical twins.