1. Cell Reproduction

2. Asexual reproduction: the cells reproduce on own, without contact with another.
Sexual reproduction: takes the genetics of two different individual to combine and form a new individual.

3. DNA (deoxyribonucleic Acid) : is a long molecule that stores genetic info. It is a double helix of nucleotides.
The pairs are: Adenine with Thymine
and Guanine with Cytosine
* These are the genetic codes found in chromosomes.

4. RNA (Ribonucleic Acid): is a single strand.
Instead of thymine, there is Uracil.
A-U
G-C
-copies code of DNA to direct protein sythesis.

5. ATP (adenosine triphosphate)
Energy transfer molecule
Formed when cell respiration releases energy form food molecules.
Used for energy requiring processes.

6. Chromosomes
Are made up of a single DNA and proteins. Are coiled up in nucleus.
Each half of a chromosome is called a chromatid.
When divide, each new cell will get 1 chromatid from each parent.
Chromatids are held together in the middle by a Centromere.

7. Sex Chromosome: determine the sex of the organism. X or Y.
Autosomes: all other chromosomes in the organism.
Human have 46 total chromosomes, or 23 pairs.

8. Each cell has 2 copies of each autosome
Each cell has 2 copies of each autosome. You receive 1 copy from each parent.
The 2 copies are called Homologous Chromosomes.
Karyotype: a picture of the chromosomes.

9. Diploid: have 2 sets of chromosomes (2N)
Haploid: 1 set of chromosomes (1N)
sex cells
Homologous Chromosomes: one of a pair of similar chromosomes. Each organism receives one copy from each parent. We have 22 pairs of homologous pairs, and one pair of sex cells.

10. Cell Divisions 2 different ways of Cell Division
1. Mitosis: which is for the body cells. Make new body and tissue cells. 1 cell will divide into 2 identical daughter cells with 46 chromosomes
2. Meiosis: is the division of the sex cells. The cells divide in half, with only 23 chromosomes and form the Gametes (egg and sperm)

13. Mitosis
1. Interphase: chromosomes make a copy

14. 2. Prophase: chromatids still attached at centromere
2. Prophase: chromatids still attached at centromere. Centrioles move to opposite poles and the spindle fiber start to appear.

15. 3. Metaphase: chromtids line up in middle
3. Metaphase: chromtids line up in middle. Center attaches to spindle fibers, and divide.

16. Anaphase: have 2 complete sets
Anaphase: have 2 complete sets. The spindle fibers pull toward the poles.

17. Telophase: DNA uncoils, membrane forms around chromosomes.

18. Cytokinesis: cytoplasm divides, a new cell is formed.

19. Meiosis
Has 2 stages. The first stage is the same as mitosis. The cell copies and divides. The those cells just divide again, and end with ½ the chromomes.
Result on formation of egg and sperm

21. Meiosis I
1. Prophase I: DNA coils up into chromosomes, spindle fibers appear, the chromosomes lime up next to its homologue called Synapsis. Each pair called a tetrad. The chromatids twist around allowing portion to break off and attach to adjacent chromatid, called Crossing-Over, which results in Genetic Recombination, a new mixture of genetic material.

23. Metaphase I: tetrads line up in middle
Metaphase I: tetrads line up in middle. Spindle fibers attach to centromere

24. Anaphase I : each homologous chromosome move to opposite pole, then have a random separation. Independent Assortment.

25. Telophase I: chromosomes reach opposite ends.
Now have 2 new cells with one chromosome from each homologous pair

26. Meiosis II
During Meiosis II, the DNA is not copied, the 2 cells go through the phases again and end in 4 cells , each has only ½ the original number of chromosomes.