Gen Biology 3rd Quarter Unit 1 PDF

Unit 1: GENETICS Deoxyribonucleic acid (DNA) Made up of four subunits known as nucleotides Genes arranged in a twisted ladder or double helix Segments of the DNA,...

Unit 1: GENETICS Deoxyribonucleic acid (DNA) Made up of four subunits known as nucleotides Genes arranged in a twisted ladder or double helix Segments of the DNA, which give structure organisms their physical characteristics Determine which traits will appear in the Nucleotides – vary according to the type offspring Located in chromosomes which of base present Purines – the larger bases are found in the nucleus of most cells ✓Adenine (A) DNA ✓Guanine (G) The materials that exist in every cell in the Pyrimidine – the smaller bases body that holds its genetic code ✓Cytosine (C) Chromosomes ✓Thymine (T) Composed of two identical sister A=T chromatids that are densely packed and G=C constricted in a region termed as centromere Chargaff’s rules - The specific pairing of nitrogenous bases Deoxyribonucleic acid (DNA) – directs the cell to make proteins that determine the DNA REPLICATION The process by which a characteristics of the cell DNA molecule separates down the middle Proteins of the ladder in order to make a copy of Tools of heredity which are manufactured itself through protein synthesis Generates two daughter molecules, each consisting of one parental DNA strand and ✓The formation of proteins using the one complementary strand information coded on DNA and carried out by RNA Made up of one or more Deoxyribonucleic acid (DNA) – used as a polymers, called polypeptides, consisting of blueprint to make a similar molecule called a specific sequence of amino acids linked ribonucleic acid (RNA) together by peptide bonds Directs the formation of proteins Proteins = polypeptides GENE EXPRESSION a.k.a. protein Amino acid = building blocks synthesis The use of genetic information in DNA THE FLOW OF GENETIC INFORMATION to make proteins Messenger RNA (mRNA) Takes place in two stages: Takes the genetic information from transcription and translation. sections of the DNA from the nucleus out into the cytoplasm FIRST STAGE: TRANSCRIPTION  The process by which mRNA is sequence of three nitrogen bases located at synthesized from the gene within the DNA the other end of the molecule Messenger RNA (mRNA) Carry instructions to build thousands of Anticodon – the set of three nitrogen bases carried by the tRNA which are proteins the body needs complementary to the bases of the mRNA Produced during transcription Ribosomal RNA (rRNA) The site of protein synthesis during Codon translation ✓Nucleotide triplet in mRNA that specifies Located in the cytoplasm or rough a particular amino acid endoplasmic reticulum of the cell ✓Order of bases determines which amino acid will be added to a growing protein chain ✓Order of amino acids will determine the structure and function of a protein Start codon : (AUG) Stop codons :(UAG; UGA; UAA) THE GENETIC CODE Contains 20 essential amino acids SECOND STAGE: TRANSLATION MUTATION The process of assembling protein Occurs when there is a change in the molecules from information coded in mRNA order of the bases in an organism’s DNA Transfer RNA (tRNA) Deletion – a base is left out Transports amino acids floating freely in Insertion – an extra base is added the cytoplasm to the ribosomes Substitution – occurs when an incorrect Specifically constructed to carry amino base replaces a correct base acid molecules from the cytoplasm of the cell to binding sites located in ribosomes Usually inherited from parents when the Type of amino acid is determined by the damage occurs in sex cells  Can also happen because of Aims to clone a particular gene for analysis environmental factors or production of a medically useful protein Repair enzymes product in large quantities Continuously works to monitor the Can be used to treat diseases like diabetes DNA molecule for errors However, repairs may be inaccurate, Vector An organism, either a virus or a so the mistakes become part of the genetic bacterium, which acts a recipient of a message desired DNA fragment II. GENETIC ENGINEERING Plasmid A circular DNA that contains A process by which an individual’s genome about 3,500 base pairs that can replicate is deliberately modified. independently inside the body of a bacterium Genome – the complete set of DNA in an organism, which contains all the Restriction Enzymes Special "molecular information needed for it to function. scissors" used to cut DNA molecules in such a way that the cut portion would have Transgenic – any organism that has a sticky ends modified or inserted gene from another species DNA Ligase acts as a glue to cause strong bonds that form between two opposing SELECTIVE BREEDING ends A technique which involves choosing and breeding an organism with the desired Step 1: Polymerase Chain Reaction – done traits by recombining the DNA from different Used in transgenic plants to produce their species to produce millions of copies of a own insecticides or become resistant to single desirable piece of DNA that mimics weed killers DNA replication Allows crops to produce vitamins needed Step 2: Molecular Cloning – done by for human health inserting the desired DNA fragment (gene) into a vector HYBRIDIZATION Step 3: Regeneration of the new organism The process of crossing plants or animals with the desired trait with different variations of the same trait with the goal of creating offsprings having 1. PEST-RESISTANT CROPS the best traits of the parents Production of crops that are resistant to destructive insects such as locusts and RECOMBINANT DNA TECHNOLOGY other pests The resulting DNA when genes of one organism are put into another using genetic 2. DISEASE-RESISTANT CROPS engineering Application of genetic engineering A technique of combining two DNA techniques to some plants to make them sequences from different sources resistant to diseases caused by many viruses, fungi, and bacteria  Milk contains proteins present in human 3. PRODUCTIVE LIVESTOCK milk but lacking in cow milk Involves the injecting of growth hormones to livestock such as dairy cows to increase milk production GENE-EDITED CHICKS AT ROSLIN INSTITUTE 4. MASS-PRODUCED DRUGS Contain an extra gene that interrupts the Done by inserting genes that produced transmission of avian flu medically-important proteins into bacteria Unlike vaccination, modification still Genetically-engineered bacteria protects the bird even if the virus mutates Produce proteins that dissolve blood clots, helping to prevent heart attacks and GENETICALLY MODIFIED POTATOES strokes Resistant to bruising and may produce Produce proteins that prevent high less acrylamide, a cancer-causing chemical, blood pressure, and proteins that help when exposed to high heat regulate kidney function CONCERNS REGARDING GMOs Vaccines Include areas of safety testing and food Prepared by inserting genes from labeling disease-causing microbes into harmless Environmental Hazards bacteria Health Risks Harmless microbes can be used to Economic Issues stimulate the body to make disease- attacking antibodies 1. ENVIRONMENTAL HAZARDS Examples of GMO Has been reported to represent a risk because most hybrids express the Bt toxin FEATHERLESS CHICKENS in pollen which could further be deposited Produced through the selective crossing other near corn fields which may cause between a naturally bare neck and a regular harm to non-target organisms that consume broiler chicken this plant Recombinant chicken would be lower in Include speculations that GM plants could calories, faster-growing, environmentally be harmful to the environment by depleting friendly, and more likely to survive in soil microorganisms which are essential for warmer conditions soil fertility and/or influence the microenvironments of other organisms GENE-EDITED PIGS Genetically-modified pigs which have 2. HEALTH RISKS been made resistant to Porcine Include allegations of allergic reactions to Reproductive and Respiratory Syndrome drugs or food that are products of GMOs (PRRS) virus, a deadly pig disease 3. ECONOMIC ISSUES ROSITA ISA Biggest concern is the lengthy and costly A cow genetically-modified to produce process of bringing GM foods to the market human-like milk which demands a profitable return on the investment agribiotechnological companies  Results to patent infringement which is a big problem in agribusiness