Define:

Character

Trait

Hybridization

Testcross

Law of Independent Assortment

Character- A heritable feature that varies among individuals such as flower color

Trait- one of the variety of possibilities for a character.

Hybridization: The mating or crossing of two true breeding varieties.

Testcross- Breeding an organism of unknown genotype with a recessive homozygote to reveal the genotype of the first gamete.

Law of Independent Assortment- states that each pair of alleles segregates independently of the other pair during gamete formation.

Heredity

Who was the first person to study genetics? How did he do it?

Experimental Design?

Heredity- The tendency for traits to be passed from parent to offspring

Gregor Mendel was the first person to study genetics, he's an Austrian Monk who worked w/ garden peas because they are easy to breed, produce a lot of offspring, and reproduce often.

Experimental Design-

 Mendel had 7 characteristics, each of which has two distinguishable traits, he let each variety self- fertilize first to ensure true- breeding.

First Law- Alternative versions of genes account for variations in inheirited characteristics.

        Alleles= alternative forms of genes

Second Law- For each character the individual receives two alleles, one from each parent.

Third Law- When the two alleles differ for the same gene the dominant trait is displayed over the recessive one.

Law of Segregation- Two alleles for a heritable trait character seperate during gamete formation.

What carries genes?

Where are the two identical genes found on this thing?

Principle of Segregation

Chromosomes

the locus

Principe of segregation- Each gamete carries only one allele for seed shape, because alleles have separated during meiosis.

Law of Independent Assortment

Dihybrid  Cross Generalities

- Each pair of alleles for one gene segregates into its gametes independently of the alleles from the parent's gene.

- In a cross between two dihybrinds ( two individuals heterozygous for two genes), the offspring will have four phenotypes in a 9:3:3:1 ratio.

How Genes Influence Traits

Primary Transcript- What are the genes encoded with?

How many genes does a chromosome carry?

Human Genome- how many nucleotides, form how many chromosomes.

How many different Chromosomes are their Total?

Primary Transcript- Each gene is encoded for the amino acid sequence for the protein it's designed to make

Each chromosome carries around 1,000 genes.

the Human Genome is composed of 3 billion nucleotides arranged to form 23 chromosomes, every person has 2 sets.

- There is 24 types of chromosomes, 22 autosomes, and 2 sex chromosomes, X and Y.

Genotype vs Phenotype

Frequency of traits appearance, is it relevant to anything?

Genotype= an organism's alleles

Phenotype= Manifestation of genotype, or how the genotype is expressed in the organism

- No relevance to occurance of traits in population, recessive traits are sometimes more frequently seen.

Human Genetics

- What can you use to study the passing down of traits?

Sickle Cell Anemia

Cystic Fibrosis

Huntington Disease

Sickle Cell Anemia- Recessive-  Problem with the cell's ability to carry oxygen. The frequency of this is 1/12 in the African- American Population.

Cystic Fibrosis- Affects mostly White people of European descent.  This occurs from a defective Ion channel. It's recessive. occurs in 1/30

Results in descreased osmosis, and thick mucus forms in lungs and other organs.

Huntington Disease- Neurons die and you do too within 10 years. It's a dominant trait, but only 1/10,000 humans have it.

Multiple Alleles, Incomplete Dominance and Co- Dominance,

Blood Types

Incomplete Dominance- Neither allele is completely dominant.

Co- dominant- occurs when a gene has several allels and some are co- dominant to each other, like blood types.

In blood their is iA, iB, iAB, or ii, only ii is recessive, all the other traits are co- dominant to each other.

Sex linked Alleles

- The chromosomal basis of Sex.

- The inheritance of Sex- Linked Genes.

- X inactivation in Female Mammals.

- Sex- Linked Alleles pattern

- Are disorder with sex chromosomes more likely to be associated with men?

The chromosomal basis- The sex of an individual is derived by which sex chromosomes are present.  Humans sex system works with X-Y, but other animals use different systems.

Inheritance of Sex- Linked Genes- The sex chromosomes carry genes for some traits that are unrelated to sex characteristics.  For example color blindness with males.  Fathers can give color blindness as a recessive trait to his daughters, but a son can only catch color blindness if his mother has or carries it.

- Sex linked genes have different patterns of inheritance than autosomal genes.  The Y chromosome is blank for these genes.

- Yes, but the disorder needs to be from a recessive gene.

 The Sex of a child is determined by what?

Polygenic Phenotypes

- A child's sex is determined by the sex chromosome that the father gives to his sperm.

Polygenic Phenotypes- Phenotypes determined by more than several genes, with each gene possibly having several different alleles.

- The alleles of each gene together determine the phenotype, so their is no discrete phenotype. and Continuous Variation occurs.

(Example Human Height)

Linked Genes

what's different if genes are on same chromosome

what importance does distance between two genes on the same chromosomes have

Crossing Over

linked genes- two or more genes on a single chromosome, the genes are often inherited together

If the genes are on the same chromosome they are linked, This means that assortment is NOT INDEPENDENT, and you have less possible genotypes in offspring ( two 1/2's, instead of four 1/4's)

-These genes since they are on the same chromosome travel together during meiosis.

- The closer two genes are on the same chromosome the less likely they are to cross- over, the further aparty they are on the same chromosome the more likely they are to cross over.

Crossing Over- the separating of linked genes found at ends of chromosomes.

DNA

def

what is it composed of

bonds

RNA

DNA- Deoxyribonucleic Acid

- polymer of nucleotides joined by phosphodiester bonds that consists of a Nitrogenous Base (either T,A,C,G), The sugar ( Deoxyribose), and a Phosphate Group.

A= adenine

T= Thymine

G= Guanine

C= Cytosine

Double Helix of Antiparallel strands, strands are held together by H- Bonds

RNA= Ribonucleic Acid

Who was DNA's structure found by? how?

What are the Purine Pyrimidine pairs?

When predicting opposite DNA or RNA strand make sure to flip the 5' to 3', or vice versa!!

- DNA was found by Rosalind Franklin using X-Ray crystallography.

- the purine pyrimidine pairs are: A-T, and G-C, they are called complementary bases.

Three Requirements:

1. Single Stranded DNA (ssDNA)

2. Enzyme and nucleotides

3. Primer to provide a starting point.

DNA Synthesis (6 Steps)

Single Strand Binding Proteins

What relieves the stress from the twisted DNA Helix?

What direction is the new DNA molecule synthesized in?

1. orgins of replication are found by a primer, which will open the double helix at the orgin site.

2. Once DNA helix is open Helicase helps open it further, creating a replication fork, which is essentially a bubble that grows.

3. At the beginning of the template strands primers are formed from RNA primase, this is necessary for DNA Polymerase to work.  The leading strand receives only one Primer, but the lagging strand receives several (Okazaki.)

4. After the primer DNA Polymerase 3 adds nucleotides to the 3' ends of the two strands.  The leading strand is built upon in one motion, but the lagging strand is formed in bits and pieces because of the several RNA fragments.

5. DNA Polymerase then goes in and removes all the RNA fragments, replacing them with DNA.

6. But there are still several nicks in the lagging strand and one in the leading strand, they are taken care of by DNA Ligase.

Notes

Single Strand Binding Proteins from on the newly split DNA's strands, stabilizing them while keeping the DNA from re- closing.

Topoisomerase- relieves the stress from the unwound portion of the DNA Helix.

- Afterwards the DNA Polymerase checks for errors, if any are found too late then it's up to enzymes to remove them.

- The new DNA molecule is synthesized in a 5' to 3' motion.

Transcription= (Basic Meaning)

2 requirements of Transcription

Differences between DNA Replication and Transcription

Transcription= RNA synthesis

Requirements

1. Single Stranded DNA

2. Enzyme and nucleotides

Differences:

Transcription used U instead of T

- uses nucleotides containing ribose instead of deoxyribose

RNA Transcription

Initiation

the Enzyme RNA Polymerase must find and bond with w/ a core promoter and with Transcription Factors (Proteins) to form the Transcription Elongation Complex.

Elongation- The template strand of DNA is traveled down by the RNA Polymerase which creates Bases to coordinate with the DNA strand, the new strand is build upon in the 5' to 3' direction.

The new copy has Uracil instead of thymine.

When finished three A's are added to the tail ceasing the RNA copying, this process is called Polyadenylation.

RNA Processing

how do the two modifications help?

RNA Splicing

RNA Processing: during this process both ends of the primary transcript are altered.

5' cap added composed of G

3' Tail added composed of 50-250 A's

Purposes:

1. Helps export mRNA from nucleus.

2. Protects mRNA from dehydration.

3. Helps ribosomes attach to the 5' end.

RNA Splicing

Introns= get removed from RNA Copy

Exons= pieces get spliced together once Introns are gone.

Translation

Initiation

Elongation

Termination

What's the Translation Initiation Complex?

3 Sites of a Ribosome.

Initiation: Small subunit of ribosome binds RNA
First tRNA (carrying f-Met) binds AUG start codon
Large subunit of ribosome binds to the small subunit

mRNA carries its genetic information as a ribonucleotide sequence as it travels towards the tRNA.

The mRNA has its codons read and is then matched with the appropriate Anti- Codon of a tRNA, which has an AA attached to its other side.

The tRNA then passes through the rRNA of the ribosome and releases its AA.

-The ribosome then strings the AA's together in the appropriate order, forming the polypeptide chain.

When a stop codon appears the codon binds with release factors which stop the forming of the polypeptide chain, and allows it to break lose.

Translation Initiation Complex: mRNA+tRNA+ 2 ribosome units.

Sites of Ribosome:

P Site= Polypeptide Chain

A Site= tRNA with AA yet to enter Ribosome

E Site= tRNA leave here after passing through Ribosome

- Reading Frames: Start one more nucleotide over for each row down when you begin reading the sequence.

-Remember to always start at the start codon and stop at the stop codon, if doing this by hand.

Mutations

Substitution

Frameshift

Substitution: Replacing one base with a different base.

Frameshift mutations: occurs when nucleotides are inserted or deleted.

Start= ATG, or AUG

Stop = TAA, TGA, TAG, or UAA, UGA, and UAG

- Enzymes that recognize specific sequences of nucleotides in DNA, and cut them.

- This helps determine possible mutations, because the mutation sequence will not get cut, like the wild type will.

Gene Expression

Monomers

Primary Transcript

Triplet Code

Gene Expression= process by which DNA directs the synthesis of proteins

Monomers= A,T,C,G

Primary Transcript= The original copy of mRNA before splicing and stuff.

Triplet Code= The genetic information to form AA's/ the polypetide chain is derived from sets of three nucleotides from the mRNA

Cellular Respiration

4 main steps

Total energy released per 1 ATP of glucose at end of Respiration is what?

Meiosis 1=

Meiosis 2=

Meiosis 1= Reductive division= seperates homologs

Meiosis 2= Separates sister chromatids

- There is no g2 in Meiosis

Prophase 1

- chromosomes condense in the nuclues and become visible. crossing over occurs here in the synapse.

- Centrosomes are formed mitotic spindle.

Metaphase 1

-Homologs line up in metaphase plate.

- Centrosomes are now completely on their sides

- Kinetochores attach to Centromeres of homolog pairs and to other kinechores.

Anaphase 1

- Homologs are pulled to each side by the microtubles of the mitotic spindle connected to the centrosomes.

- Un connected Kinetochores push the cell apart extending it.

- The two cells now contain one complete set of chromosomes

Telophase 1

The cell begins to pinch

Prophase 2

Cells become visible again and new centrosomes appear with mitotic spindle.

Metaphase 2

Cells line up again on metaphase plate with kinetochores connecting to their centromeres and the kinetocheres also connect to themselves.

Anaphase 2

The sister chromatids begin to get pulled to their respective sides from the kinetochore.