3.24a Mitosis

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

• Mitosis is a form of cell division which results in growth and the growth occurs by an increase in the number of cells.
• The number of chromosomes in the nucleus is known as the diploid - 2n. 2n = 46
• Each of the diploid cells has a nucleus. Often say that the cells are identical / daughter.
• They are identical because, they have the same number of chromosomes and because they have the same set of chromosome.

3.16 DNA and Genetic information

chromosomes= contain 1000's gene

gene loci--> double helix ( theres two, theres a pair to be parallel) --> sugar-phosphate backbone ( no chemical details required) is holding these two strands together

In the center theres a group of molecule called bases which there is 4 different type of base:

-adenine (A)

-thymine  (T)

-cytosine (C)

-guanine (G)

These bases are holding the two helixes they are held together by paring each other:

A=T

G=C

these are base pairs, these are always found in the DNA, they are glueing together from one side of the double helix with the other

(expand) =ACTGAACCAG : order of molecule this order is the GENE (inside the nucleus/order of bases/number of bases= construction of protein in the cytoplasm--> giving us the characteristic) 

Q: how to each molecule know which one to pair to?

http://bellebiology.blogspot.com/2011/08/316-dna-and-genetic-information.html

3.15 Genes

-- the gene carries information:

--characteristics of the organism

-- blood group

-- petal colour

- there will be a gene for each one of those

-the genes are located in the nucleus and the information is pass to the cytoplasm and in the cytoplasm the genetic information is transformed into the protein 

-which this protein controls the production of the characteristics

Q:Why and how do different people have different types of DNA/genes?

http://bellebiology.blogspot.com/2011/08/315-genes.html

3.14 Chromosomes

-chromosomes are the genetic information within a cell

-in each cell there will be a nucleus which contains a number of chromosomes 

- chromosomes are compose of a molecule called DNA (Deoxyribonucleic acid) which forms a shape known as the double helix

- and within the section is called genes

-1 chromosomes contains many genes about 1000 of genes

- each genes carry the information for the construction of a protein 

- the protein gives out the characteristic associated with the genes such as the blood group

- different organism has different number of chromosomes

Q: If chromosomes can't be reproduce, where do we get it from?
- does the chromosomes live inside you forever?
- or do they reproduce

http://bellebiology.blogspot.com/2011/08/314-chromosomes.html  

3.1 Sexual and Asexual reproduction

3.1 Describe the differences between Sexual and Asexual reproduction

• Organisms that show sexual reproduction show sexes (male/female). No sexes exist in Asexual reproduction.
• Sexual reproduction has Gameke cells in the sperm and egg cells. Asexual does not have Gameke cells.
• Meiosis is a cell division that produces Gamekes. One of Meiosis' effects is to half the number of chromosomes in the Gameke cell. 
•  Total number of chromosomes in a human is 46 per cell. In Gamekes the total number is 23 per Gameke cell. From 46 to 23 is the process of Meiosis.
• In Asexual reproduction there is Mitosis and Binary fission bacterial cells. Number of chromosomes is maintained constantly.
• In Sexual reproduction there is the process of fertilisation, where the sperm cell and egg cell fuse together. In Asexual reproduction there is no fertilisation and no fusion of cells.
• Many differences in the individuals of a sexual reproducing population. Where as Asexual show a small amount of variation, mainly identical (clone).  

What is the process of Meiosis?