Everything there is to know about DNA Mitosis Meiosis RNA synthesis Genetic engineering Mendelian genetics

Mitosis = cell cycle a. Process through which a body cell replicates itself. b. Process produces two NEW body cells. c. Cells must be identical to each other. d. Process takes place continuously, at the rate of once every 24 hours

Mitosis is controlled by the codes found on DNA. DNA is found on chromosomes. There are many interchangeable terms that are used to talk about genetic codes.

DNA = DEOXYRIBOSE NUCLEIC ACID CHROMOSOMES = GENERIC TERM TO MEAN THE CODES FOUND ON DNA. CHROMATID = A PAIR OF CHROMOSOMES: CHROMATIN= A PAIR OF CHROMATID CENTROMERE CHROMATID

MITOSIS involves 6 steps. 1.Interphase – longest phase “resting” phase cell matures organelles develop process begins: nuclear membrane breaks down DNA duplicates organelles replicate

DNA DUPLICATION DNA is composed of: phosphate groups –PO 3 ribose group nitrogen bases: thiamine adenine guanine cytosine thiamine always bonds with adenine guanine always bonds with cytosine

C G T A A T G C C G A T T A PHOSPHATE RIBOSE

T A GCGC C A T A T C G G T A

T A GCGC C A T A T C G G T A A T C G G T A TA GCGC C A T

2.Prophase – chromatin become visible centrioles appear spindle fibers appear chromatin begin to move 3.Metaphase – chromatin line up along equator of cell prepare to separate 4.Anaphase – chromatin separate to become individual chromatid.

2.Prophase – chromatin become visible centrioles appear spindle fibers appear chromatin begin to move 3.Metaphase – chromatin line up along equator of cell prepare to separate 4.Anaphase – chromatin separate to become individual chromatid.

2.Prophase – chromatin become visible centrioles appear spindle fibers appear chromatin begin to move 3.Metaphase – chromatin line up along equator of cell prepare to separate 4.Anaphase – chromatin separate to become individual chromatid.

2.Prophase – chromatin become visible centrioles appear spindle fibers appear chromatin begin to move 3.Metaphase – chromatin line up along equator of cell prepare to separate 4.Anaphase – chromatin separate to become individual chromatid.

There are now two new cells that are identical to each other. They contain the ribosomes and mitochondria made during interphase. The cells will now begin the process of producing the organelles that are not yet present in the cell, like … When all the organelles are present, the cell will enter interphase and the process will begin all over again.

Meiosis Reduction Division

Meiosis is the process by which gametes are coded with inheritable traits. Remember: for every genetic trait, an organism must inherit 2 alleles - one from the father and one from the mother. In sexual reproduction, an offspring is the result of the union of two cells - an egg and a sperm. These two cells are called gametes. Each gamete contains one allele for each inheritable trait.

Mitosis: production of body cells one duplication of DNA one cell division resulting cell contains all the DNA of the parent cell - diploid resulting cell contains both alleles for each trait human cell: 46 chromosomes 23 pairs = 2 alleles for each trait diploid number

Meiosis: production of gametes one duplication of DNA two cell divisions resulting cell contains half the DNA of the parent – haploid resulting cell contains one allele for each trait. Gamete = sperm/egg 23 chromosomes 1 allele for each trait haploid number

23 46 Egg sperm offspring Haploid # haploid # diploid # One allele one allele two alleles

4 gametes each with the haploid number

B R d R w B R W d b R d w Egg - haploid Sperm - haploid Diploid Eye color Bb heterozygoous Hair color RR homozygous dominant Dimples dd homozygous recessive Widow’s peak Ww heterozygous W d b

B R W d b R d w B r D W B r D W B R W d b R d w B r D W B r D W Offspring B b BBBB BB Bb R rrrr Rr

RNA and PROTEIN SYNTHESIS

There are two types of nucleic acids: 1.DNA 2. RNA

Let’s review a few terms: Protein: structure: long chain of C,H, O, N, and S Amino acid: building blocks of proteins structure: made up of 3 nitrogen bases function: necessary for cellular growth and repair large covalent molecules produced in the ribosomes enzymes-speed up chemical reactions.

Enzymes-specific for compounds they digest. Without these enzymes, the matching compounds will not be digested or broken down. Because these enzymes are specific there must be a code for their production. Lactase - lactose. Amylase - simple starches Pepsin - food proteins

RNA will provide the code for protein synthesis. Each protein performs a specific function and therefore requires a specific code. This code will come from DNA.

DNA: A T C G G C A T T A G C DNA code is found in the ….. Proteins are made in the ……

DNA: TGCTACTGCTAC ACGATGACGATG

TGCTACTGCTAC ACGATGACGATG mRNA ACGAUGACGAUG

DNA: ACGATGACGATG mRNA ACGAUGACGAUG tRNA U G C U A C

DNA: ACGATGACGATG mRNA ACGAUGACGAUG tRNA U G C U A C rRNA A C G A U G

rRNA A C G A U G Ribosomal RNA or rRNA now has the Code it needs to make specific Proteins needed by the organism. The code for this rRNA is ACGAUG. Each Letter stands for a nitrogen base. The Ribosome will ‘read’ the nitrogen bases In groups of three. Every three nitrogen Bases = an amino acid. Several amino Acids grouped together = a protein. ACG = amino acid = threonine AUG = amino acid = methionine

Mendellian genetics Gregor Mendel The father of genetics Monk Gardener

Heredity - process through which traits are passed on from one generation to another. Trait – any visible or invisible characteristic, function, or process that is a necessary part of an organism. Gene –structure that contains the code for every trait. DNA Allele – particular form of a trait. There are at least two alleles for every trait: one dominant one recessive

Dominant – the allele for a trait that is ALWAYS seen in the organism. Recessive – the allele for a trait that can be masked by the dominant trait. Every chromosome (2 chromatids) will be composed Of two alleles! chromatid Allele 1Allele 2 Allele 1 and allele 2 are carrying the codes for the same trait. One allele comes from the mother, the other from the father.

Dominant – the allele for a trait that is ALWAYS seen in the organism. Recessive – the allele for a trait that can be masked by the dominant trait. Every chromosome (2 chromatids) will be composed Of two alleles! chromatid Allele 1Allele 2 Allele 1 and allele 2 are carrying the codes for the same trait. One allele comes from the mother, the other from the father.

Combinations of alleles result in what an offspring inherits. And what an offspring inherits determines what the offspring looks like and how that offspring functions. POSSIBLE COMBINATIONS: HOMOZYGOUS HETEROZYGOUS bB bb BB

COMBINATIONS OF ALLELES WILL DETERMINE WHAT THE OFFSPRING LOOKS LIKE = PHENOTYPE. COMBINATIONS OF ALLELES WILL DETERMINE THE WAY AN OFFSPRING FUNCTIONS, I.E. ITS CODE= GENOTYPE. THERE ARE THREE TYPES OF GENOTYPE: HOMOZYGOUS DOMINANT HOMOZYGOUS RECESSIVE HETEROZYGOUS

Homozygous dominant Gene carries two dominant alleles for any trait Phenotype: red flower Genotype: RR (purebred)

Homozygous recessive Gene carries two recessive alleles for any trait. Phenotype: white flower Genotype: rr (purebred)

Heterozygous Gene carries one recessive allele and one dominant allele Phenotype: red flower Genotype: Rr (hybrid)

Heredity and genetics are processes that involve chance=probability-the chance of something happening. Traits are inherited by the passing on of two alleles-either dominant or recessive or both. This inheritance and chance are predicted by using punnett squares.

Punnet square--used to predict possible genotype of an offspring when the genotype of the parents is known. Once genotype is known, the phenotype will be decided. father mother 25% Chance of an offspring 25% Chance of an offspring 25% Chance of an offspring 25% Chance of an offspring

R rrrr Mother : Phenotype white Genotype homozygous recessive Father: Phenotype red Genotype homozygous dominant Rr 25% Rr 25% Rr 25% Rr 25% Offspring: 100% heterozygous - genotype 100% red - phenotype mother father

Mother: Father: Phenotype: short Phenotype: tall Genotype: homozygous recessive Genotype: heterozygous T t tttt Tt tt 25% Tt tt 25% Offspring: 50% tall 50% short - phenotype 50% heterozygous - genotype 50% homozygous recessive - genotype

Red sweet pea White sweet pea Pink sweet pea Homozygous Homozygous Heterozygous Dominant recessive