the genetic makeup of an organism

listings of alleles an individual cares for a specific gene

a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA

most of the genes of a eukaryote are located in its chromosomal DNA, a few are carried by the DNA of mitocondria and chloroplast

determines the organisms apperance (phenotype) of a gene when the individual is heterozygous for that gene

ex.: freckles, free earlobes, widows peak, polydactyly, huntington's disease

has no noticable effect of the phenotype of a gene when the individual is heterozygous for that gene

a diagram used in the study of inheritance to show the results of random fertalization

shows 4 possible combinations of gametes

1. prevented self fertilization by removing immature stamens of a purple flower before they produced pollen

2. cross-fertilized the stamen less purple flower: he transferred pollen from stamens of a white flower to the carpel of the purple flower

3. pollinated carpel matured into pod

4. the planted seed from the pod

deduced the fundemental principles of genetics by breeding garden peas

-p for parental

true-breeding parent plants (PP,pp)

deduced the 3D (secondary) structure of DNA w/ x-ray crystallagraphy from rosalind franklin and maurise wilkins

genes in DNA provide instruction for making a protein

chain of command is from DNA in the nucleus

carries instructions of DNA in the nucleus that are used by ribosomes to create protien in the cytoplasm

bridge from DNA to protien

the transfer of genetic information from DNA into a messenger RNA (mRNA)

takes place in the nucleus

gene is transcribed ;RNA is made). mRNA is single stranded; RNA polymerase is the enzyme which carries out transcription

mRNA is used by ribosomes to insert te correct amino acids in the correct sequence to form the protien coded for that gene

the sequence of nucleotides in the mRNA determines the sequence of amino acids in the protein

takes place in the ribosomes and cytoplasm

3steps :

1.initiation

2.elongation

3. termination

seperates DNA molecules based on size

-DNA sample is placed at 1 end of a porous gel, current is applied and DNA molecules move from 1 negative electrode toward the positive electrode

- shorter DNA fragments mover quicker and further through the porous gel

DNA fragments appear as bands, visualed through staining/detecting radioactivity/ fluorescence

- each band is a collection of molecules of the same length

special bacterial enzymes that cut DNA

proteins that bacteria use to prevent the invasion of foreign DNA such as viruses that attack bacteria

these enzymes act as scissors, cutting foreign DNA into non-functioning pieces

they recognize and cut at specific sites along the DNA molecule

each restriction enzyme has a secific restriction site, usually a 4- or 6-base pair sequence that is a palidrome

a change in the nucleotide sequence of DNA

-can be spontaneous (due to erroes in DNA replication or recombination), inherited, or induced by mutagens (high energy radiation/chemicals)

replacement of one nucleotide w/ another

- effect depends on whether there is an amino acid changes that alters the function of the protein

tRNA structure allows it to convert 1 language to the the other (the nucleic acid language to protein language)

multiple different types, each type of tRNA molecule can bind to 1 specific type of amino acid on 1 end, on the other end tRNA has 3 nucleotides that form a anti-codon

brings together

codon marks the start of an mRNA message

2 steps:

1. mRNA binds to a smalll ribosomal subunit and the 1st tRNA binds to mRNA at the start codon

2. a large ribosomal subunit joins the small subunit, allowing the ribosome to function

addition of amino acids to the polypeptide chain

3 steps:

1. codon recognition

2. peptide bond formation

3. translocation

continues until the ribosome reaches a stop codon

alters the reading frame of mRNA so that nucleotides are grouped into different codons

leads to significant changes in amino acid sequences down stream of mutation

causes a non-functional polypeptide to be produced

cell specialization

cells become specialized in structure and function

controled by turning specific sets of genes on or off

as cells divide the mRNA is translated and the protein direct the differentiation of cells resulting in the subdivision of embryos into different levels/tissue types

retain a complete set of their genes just dont express all of them

-each cell has the same DNA as every other cell in the body

the overall process of information flow from genes to protiens

-if a gene is being expressed it is usually being transcribed

- a gene that is "turned on" is being transcribed to produc mRNA that is translated to make it corresponding protein

- packing and unpacking of chromosomal DNA provide a course adjustment for eurkaryotic gene expression by makeing a region of DNA either more or less avialable for transcription

-a gene which can cause cancer when present in a single copy in the cell

-can be viral (genes inserted into host chromosomes

- can be mutated versions of proto-oncogenes

- a cell can aquire an oncogene either from a virus or the mutation of one of its own genes

-many proto-oncogenes code for growth factors-proteins that stimulate cell division

proto-oncogenes can be converted to oncogenes by:

-mutations causing increased protein activity

- increased number of gene copies causing more protein to be produced

-change in location putting the gene under control of new promoter for increased transcription

-normally inhibit cell division

mutations inactivate the genes and allow uncontrolled division to occur

4 or more somatic mutations usually required to produce a cancer cell

-colon cancer

1. increase in cell division and oncogene activated

2. growth of polypeptide and tumor-suppressor gene inactivated

3. growth of malignant tumor and 2nd tumor-suppressor gene inactivated

-genes act in sequential order w/ products of 1 set of genes influencing the activity of the next set of genes, to define and organize smaller and smaller reqions of the embryo, while the embryo in each cell begins to differentiate

each cell doesnt have the potential to become any cell in the body but still retains the ability to become many different cell types

produces embronic stem cells (cells that in the early animal embryo differentiate to give rise to all the cell types in the body) that can serve to replace nonreproducing specialized cells ass needed

-supplies cells for the repair of damaged/diseased organs

-controlled by complex series of proteins

-regulatory proteins bind to control sequences

-eukaryotic chromosomes undergo multile levels of folding and coiling called DNA packing

DNA packing can prevent transcription

a eukaryotic DNA sequence that helps stimulate the transcription of a gene at some distance from it

related gened located on different chromosomes can be controlled by similar enhancer sequences

small, circular DNA molecules that replicate sperately from the much larger bacterial chromosome

- can carry virtually any gene and are passed on from 1 generation of bacteria to the next

-key tools for gene cloning

often used as vectors (gene carriers)

1.plasmid DNA is isolated

2.DNA containing the gene of interest is isolated

3.plasmid DNA is treated w/ restriction enzyme that cutes 1 place, opening the circle

4.DNA w/ the target gene is treated w/ the same enzyme and many fragments are produced

5.plasmid and target DNA are mixing and associated w/ each other

6.recombinant DNA molecules are produced when DNA ligase joins plasmid and target segments together

7.the recombinant DNA is taken by bacterial cell

8. the bacterial cell reproduces to form clone of cells

the DNA sequence recognized by a particular restriction enzyme and to which it binds

-once recognized the restriction enzyme cuts both strands of DNA at specific points w/ in the sequence

-formed by complementary DNA sequence fragment's sticky ends accociating

2 different sources:1 source contains the gene that will be cloned and another source is a gene carrier called a vector

food that can deliver vaccines

more nutritious foods

faster growing fish, fruit and nut trees

drought resistant organisms

organisms resistant to herbicides and pests

mass produced protein such as insulin

clean up the enviornment

potential human health impact

potential enviornmental imact

domination of world food production by few companies

increasing dependance on industrialized nations by deceloping countries

violation of natural organisms intristic values

tampering with nature by mixing genes among species

objections to comsuming animal genes in plants and vice versa

stress for animal

labeling not require in some countries

analysis of DNA fragments to determine whether they come from a particular individual

compares genetic markers from noncoding regions that show variation between individuals

-involves amplification (copying) of markers for analysis

-size of amplified fragments are compared

genetic markers used in DNA profiling

STRs are short DNA sequences that are repeated many times in a row at the same location

number of repeating units can differe between individuals

an enzyme, essantial for DNA replication, that catalyzes the covalent bonding of adjacent DNA strands

-used in genetic engineering to paste a specific peice of DNA containing a gene of interest into a bacterial plasmid or other vector

the base unit of the genetic code

-a 3 nucleotide sequence in mRNA that specifies a particular amino acid or polypeptide signal

set of rules giving the correspondence between codons in RNA and amino acids in proteins

-redundant-more than 1 codon for some amino acids

-unambiguous- any codon for 1 amino acid does not code from any other animo acid

- molecules that match an amino acid to it corresponding mRNA codon

-type of RNA that functions as an interpreter in translation

- each tRNA has a specific anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA

begins at special sites called origins of replication, proceeds in both directions and creates replicatiosn bubbles

the parental DNA strands open up as dqughter strands elongate on both sides of each bubble

-enzymes use each parental strand to assemble new nucleotides into a complementary strand

-using the enzyme DNA polymerase, the cell synthesizes one daughter strand as a continuous peice, the other as a series of short peices, which are then connected by the DNA ligase