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MODERN GENETICS WHO DISCOVERED THE STRUCTURE OF DNA? EVERYONE SEEMS TO KNOW WATSON AND CRICK, BUT WHO IS THIS?

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MODERN GENETICS T.H. MORGAN OFFERED FIRST EVIDENCE OF WHAT SUBSTANCE INSIDE LIVING THINGS CONTROLS THEIR TRAITS LIKE MENDEL, THE TRICK TO BEING SUCCESSFUL LIED IN WORKING WITH AN ORGANISM THAT COULD GIVE MANY GENERATIONS QUICKLY!! HENCE, FRUIT FLIES

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MODERN GENETICS T.H. MORGANS WORK LED TO THE FOLLOWING UNDERSTANDING: CHROMOSOMES CONTROL SEX (GENDER) SEX-LINKED TRAITS GENE LINKAGE

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MODERN GENETICS SEX DETERMINATION AND CHROMOSOMES A SPECIFIC PAIR OF CHROMOSOMES, KNOWN AS THE SEX CHROMOSOMES, DETERMINES THE GENDER OF ANY INDIVIDUAL

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MODERN GENETICS SEX-LINKED TRAITS OBSERVE THE PEDIGREE CHART WHAT PATTERN DO YOU NOTICE?

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MODERN GENETICS SEX-LINKED TRAITS WHEN A TRAIT APPEARS TO BE DISPLAYED IN ONE GENDER MORE FREQUENTLY THEN ANOTHER, AND THE ONLY DIFFERENCE BETWEEN EACH GENDER IS THE SEX CHROMOSOMES; THE TRAIT MUST BE ASSOCIATED/LINKED TO THE SEX CHROMOSOMES X-LINKAGE VS. Y-LINKAGE

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MODERN GENETICS EXAMPLES OF X-LINKED TRAITS: RED-GREEN COLORBLINDNESS HEMOPHILIA

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MODERN GENETICS GENE LINKAGE IT WAS DISCOVERED THAT GENDER AND TRAITS ARENT THE ONLY THINGS THAT CAN BE LINKED ANY PAIR OF TRAITS FOUND ON THE SAME CHROMOSOME ARE CONSIDERED LINKED WHAT DATA WOULD SUGGEST THAT TRAITS ARE LINKED? *HERES A HINT

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MODERN GENETICS IF GENES ARE LINKED, HOW CAN THEIR BE PEOPLE WITH BROWN HAIR AND BLUE EYES? CROSSING OVER!! EXCHANGE BETWEEN HOMOLOGOUS CHROMOSOMES DURING SYNAPSIS OF MEIOSIS

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MODERN GENETICS RANDOM QUESTION IN HUMANS, DOES HEIGHT OCCUR IN JUST TWO FORMS; TALL VERSUS SHORT? HOW CAN WE EXPLAIN THE LARGE RANGE OF PHENOTYPES FOR HUMAN HEIGHT? POLYGENIC INHERITANCE MORE THAN ONE GENE CONTROLS THE SAME TRAIT, CREATING A LARGE NUMBER OF POSSIBLE PHENOTYPES

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MODERN GENETICS AFTER UNDERSTANDING ABOUT THE DIFFERENT PATTERNS OF INHERITANCE, THIS STILL LEFT AN UNANSWERED QUESTION WHAT WAS THE ACTUAL SUBSTANCE THAT CONTROLLED THESE TRAITS TO BEGIN WITH?

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MODERN GENETICS THE GREAT DEBATE PROTEIN VS. DNA BY THE EARLY 1900S, SCIENCE HAD ALREADY LEARNED OF THE EXISTENCE OF CHROMOSOMES AND THAT THESE CHROMOSOMES WERE COMPOSED OF BOTH PROTEINS AND NUCLEIC ACIDS LITTLE WAS KNOWN ABOUT NUCLEIC ACIDS, AND PROTEINS WERE WELL UNDERSTOOD AT THAT TIME AS PROTEINS WERE FOUND TO EXIST IN EVERY SUBSTANCE INVOLVED IN TRAITS, THEY WERE THE FRONT-RUNNER FOR THE ACTUAL SUBSTANCE THAT CONTROLLED TRAITS

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MODERN GENETICS ENTER THE MOUSE-KILLER SIR FREDERICK GRIFFITH

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MODERN GENETICS GRIFFITHS EXPERIMENTS WERENT ENOUGH FOR THE SKEPTICSBUT EVEN THE SKEPTICS COULDNT DENY THE FINDINGS OF

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MODERN GENETICS HERSHEY AND CHASE EXPERIMENT

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MODERN GENETICS ONCE IT WAS ESTABLISHED THAT DNA CONTROLLED TRAITS, THERE WAS A MAD RUSH TO FIND OUT THE STRUCTURE OF DNA WHY IN THE WORLD WOULD SCIENTISTS CARE SO MUCH ABOUT THE STRUCTURE OF DNA? STRUCTURE DENOTES FUNCTION

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MODERN GENETICS WHILE SCIENTISTS FIGURED OUT THE BUILDING BLOCKS OF DNA, HOW THOSE BUILDING BLOCKS GOT PUT TOGETHER ELUDED THEM

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MODERN GENETICS ENTER OUR HEROS WATSON AND CRICK CREDITED WITH IDENTIFYING / DISCOVERING THE STRUCTURE OF DNA!!!

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MODERN GENETICS DNAS STRUCTURE

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MODERN GENETICS DNAS STRUCTURE DNA IS A DOUBLE HELIX (TWISTED LADDER) ADENINE ALWAYS PAIRS WITH THYMINE AND CYTOSINE ALWAYS PAIRS WITH GUANINE EXPLAINED THE IMMENSE COMPLEXITY OF TRAITS (HOW DOES IT LEAD TO COMPLEXITY?) UNEXPECTEDLY EXPLAINED WHY DNA CAN MAKE IDENTICAL COPIES OF ITSELF (IDENTICAL OFFSPRING)

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MODERN GENETICS DNA REPLICATION

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MODERN GENETICS LEARNING THE STRUCTURE OF DNA STILL LEFT AN UNANSWERED QUESTION HOW WAS DNA THE SUBSTANCE THAT CONTROLLED AN INDIVIDUALS TRAITS, IF PROTEINS WERE WHAT WERE PRESENT THAT ACTUALLY SEEMED TO CONTROL THE APPEARANCE OF THE TRAIT? SOMEHOW, DNA HAD TO BE CONTROLLING THE SYNTHESIS OF PROTEINS

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MODERN GENETICS WHERE IS DNA FOUND? WHERE DOES PROTEIN SYNTHESIS TAKE PLACE? DOES DNA EVER LEAVE THE NUCLEUS? NO!!! HOW CAN DNA BE USED TO MAKE PROTEINS IF IT NEVER GOES NEAR THE RIBOSOMES IN THE CYTOPLASM?

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MODERN GENETICS HOW CAN DNA BE USED TO MAKE PROTEINS IF IT NEVER GOES NEAR THE RIBOSOMES IN THE CYTOPLASM? (HINT - HOW CAN TWO PEOPLE COMMUNICATE WHO NEVER SEE EACH OTHER AND DONT HAVE TELEPHONES?) THEY CAN WRITE TO EACH OTHERWHICH IS EXACTLY WHAT DNA DOES, IT WRITES A MESSAGE TO BE SENT TO THE RIBOSOMES ENTER OUR MESSENGER RNA !!

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MODERN GENETICS RNA VS DNA

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MODERN GENETICS THE PROCESS OF DNA WRITING A MESSAGE IN THE FORM OF RNA IS CALLED: DNA TRANSCRIPTION DNA mRNA ALL WE HAVE IS A MESSAGE, WE HAVENT MADE A PROTEIN YETWHERE DO PROTEINS GET MADE? THE mRNA CAN GO VISIT THE RIBOSOME FACE TO FACE

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MODERN GENETICS THE RIBOSOME USES THE mRNA AS THE INSTRUCTIONS ON HOW TO MAKE A PROTEIN WHAT IS THIS PROCESS OF MAKING A PROTEIN CALLED? PROTEIN SYNTHESIS WHAT DOES A PROTEIN LOOK LIKE? A LONG CHAIN OF AMINO ACIDS HOW DOES PROTEIN SYNTHESIS WORK? THE mRNA TELLS THE RIBOSOME WHAT THE ORDER OF AMINO ACIDS SHOULD BE IN BUILDING A PROTEIN

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MODERN GENETICS PROTEINS ARE MADE UP OF AMINO ACIDS; STUDIES HAVE SHOWN THAT THERE ARE 20 DIFFERENT AMINO ACIDS THERE ARE ONLY 4 NITROGENOUS BASES IN mRNA; A, U, C, GHOW CAN 4 LETTERS = 20 DIFFERENT BASES?

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MODERN GENETICS

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I FORGOT TO TELL YOURIBOSOMES DONT SPEAK PROTEIN (IN OTHER WORDS THEY DONT KNOW WHAT AMINO ACID MATCHES A CODON) WE NEED A SPECIAL TRANSLATOR ENTER tRNA SPEAKS BOTH CODON AND PROTEIN, SO IT TRANSLATES AND TRANSFERS THE CORRECT AMINO ACID

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MODERN GENETICS LETS LOOK AT IT OVERALL PROTEIN SYNTHESIS TRANSCRIPTION TRANSLATION

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MODERN GENETICS REMEMBER, EVERY CELL IN YOUR BODY HAS THE EXACT SAME DNAWHY IS THAT? WE HAVE EXPLAINED HOW DNA ACTS AS THE INSTRUCTIONS FOR MAKING PROTEINSSO HOW COME EVERY CELL IN YOUR BODY DOESNT MAKE THE EXACT SAME PROTEINS DIFFERENT CELLS USE DIFFERENT PARTS OF DNA WE CONTROLS/DETERMINES WHAT PARTS OF DNA ARE USED? WE CALL THIS FIELD OF STUDY GENE EXPRESSION

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MODERN GENETICS GENE EXPRESSION IS ONE OF THE MOST COMPLICATED/LEAST UNDERSTOOD AREAS OF GENETICS/SCIENCE TODAY THE SIMPLE EXPLANATION IS THAT MOST GENES ARE LIKE LIGHT SWITCHES, THEY CAN BE ON OR OFFWHEN THEY ARE ON THEY ARE MAKING PROTEINS, WHEN THEY ARE OFF, THEY ARENT

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MODERN GENETICS WHAT CAN TURN THE SWITCHES ON OR OFF? OTHER GENES ENVIRONMENTAL FACTORS **MUST REMEMBER THE ENVIRONMENT CAN EFFECT GENE EXPRESSION

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MODERN GENETICS UNDERSTANDING GENE EXPRESSION MAY UNLOCK CURES TO DISEASES SUCH AS CANCER ONCOGENES

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MODERN GENETICS WHAT DO WE DO WITH ALL THIS INFORMATION ON GENES? APPLIED GENETICS IS NEXT!!