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Hypothesis vs. Theory. Hypothesis: Theory:. An educated guess. A hypothesis that has been tested many times and has a lot of data supporting it. Ex the theory of evolution. DNA - double helix shape -like a winding staircase. Adenine. Composed of 4 bases 1. 2. 3. 4.
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Hypothesis vs. Theory • Hypothesis: • Theory: An educated guess. A hypothesis that has been tested many times and has a lot of data supporting it. Ex the theory of evolution.
DNA -double helix shape -like a winding staircase
Adenine • Composed of 4 bases 1. 2. 3. 4. • Always bond together • A nucleotide is made up of a ______ ________ • and _______. Thymine Guanine Cytosine A-T, C-G Sugar Phosphate base
DNA is complementary • The sequence of bases on one strand determines the sequence of bases on the other. What is the complement to this single strand of DNA? Watson and Crick – 2 scientists that figured out the double helix shape of DNA. -(although they actually used the work of other scientists to figure it out-Rosalind Franklin)
DNA Replication • When cells Replicate DNA makes an exact _______ of itself. • DNA serves as a template (the parent). • Each DNA molecule has 1 _______ and 1 _______ strand. This is called _____________ Copy Old New Semi-conservative replication
RNA Structure • Serves as a messenger between the DNA and the Protein. • Carries information in order to make Protein in the Ribosomes.
RNA Structure Vs DNA Structure • Name the 3 difference between DNA and RNA 1. 2. 3. DNA=double stranded, RNA=single stranded DNA has Thymine RNA has Uracil DNA has Deoxyribose sugar RNA has Ribose sugar
Transcription Pre-
Central Dogma • DNA -> ___________->_____________ mRNA Protein
DNA • Information stored in the ___ is transferred out of the nucleus using ______ and taken to the _________ where proteins are made. • AAUGGCUGUAUU • Every 3 bases is called a ________(think code) • How many codons are shown above? mRNA Ribosome Codon 4
2nd letter of codon 3rd letter of codon 1st letter of codon
Start codon = AUG • Translation always starts at this codon • Stop codons = UAA, UGA, UAG • Translation stops when ribosome comes across stop codon • A protein is a string of amino acids connected and ___________ Folded
Mutations • Changes in an organism’s (DNA) structure. • Different types: Deletion Frameshift Insertion Inversion Substitution
Substitution Insertion
Genetics The study of heredity
Remember alleles are different versions of the same ________. • Homozygous: • Heterozygous: • Trait: Gene Same Alleles, DD or dd Different Alleles, Dd Observed expression of a gene, the physical appearance
Allele Symbols Dominant allele = Capital letters, T=tall Recessive allele = Lowercase letters, t=short
Genotype vs. Phenotype Question: Can two organisms have the same phenotype but have different genotypes? Explain.
Punnet Squares • Used to predict possible genotypes and phenotypes of a genetic cross • What are possible combinations of these P1 alleles? (remember, 2 alleles for each trait) • Mom = TT Dad = TT • Mom = tt Dad = tt • Mom = Tt Dad = Tt • Mom = TT Dad = Tt • Mom = tt Dad = Tt 100% TT 100% tt 25%TT, 50%Tt 25%tt 50% TT, 50% Tt 50% Tt, 50% tt
Try this one out: Genotype Phenotype TT = Tall Tt = ___ tt = short What is the phenotypic ratio? These are called monohybrid crosses Tall 75% tall: 25% short
Mitosis vs. Meiosis • Mitosis makes _________ cells which are ___n or _____________. • Meiosis makes_________ cells which are ___n or _____________. • n+n=2n This is called ___________. • ____________ is when pieces of homologous chromosomes break off and switch places. Body 2 diploid Gamete 1 haploid fertilization Crossing over
Cell Theory • 1. All living things are composed of one or more cells. • 2. Cells are the smallest, basic unit of life. • 3. New Cells come only from other living cells.
Types of Cells • Prokaryotes • Eukaryotes Unicellular, bacteria, lack membrane bound organelles and nucleus Have membrane bound organelles and nuclei. Eukaryotes like YOU
All cells have… • 1. • 2. • 3. • 4. DNA Ribosomes Cell membrane Cytoplasm
Plasma Membrane • Phospholipid bilayer • Polar outsides • Likes water • Nonpolar insides (fatty acids – like oil in vinegar) • Hates water! • Helps maintain equilibrium • Numerous proteins throughout • Mainly for transport in and out of cell http://home.earthlink.net/~shalpine/anim/Life/memb.htm
Mitochondria Where energy in the form of ATP is made. - The kreb cycle occurs in the mitochondria. The kreb cycle is a process the mitochondria uses to make energy.
Chloroplasts Only found in ___________ cells plant photosynthesis Where ________________ takes place CO2 + H2o = sun energy C6H12O6 + O2
Proteins Amino acids • Chains of_____________ • Provide structure for tissues and organs and help w/ metabolism • Made in the ___________ • Enzymes – proteins found in living things that _________ Reactions • Proteins can be denatured by ___________________ ribosomes Speed up Heat, salt, extreme pH
Carbohydrates • Composed of carbon, hydrogen and oxygen bonded covalently. • Monosaccharide – single sugar (glucose or fructose) • Disaccharide – 2 sugar molecules bonded • Ie. ________ (table sugar!) • Polysaccharide – multiple _________ bonded together. • Ie. Starch, Glycogen, Cellulose (plant sugar!)
Natural Selection phenotype PAST PRESENT genotype • Natural selection acts on ________ rather than _________. • Those best suited for their environment will ________ (taller giraffes). • Those least suited for their environment ___ faster and leave ________ offspring (short giraffes). survive die fewer Tt tt tt TT Tt tt tt tt
Genetic variation is essential! • _________ promote genetic variation, which helps ensure a species survival • Reproduction(CO) promotes genetic variation which helps to ensure a species survival Mutations
Charles Darwin • 1st credited with theory of Evolution by natural selection • Wrote the Origin of Species • Book based on his observations during trip
Genetic drift • Change in a population due to ________ • Examples are___________ and ________ • ______ populations are susceptible • Can ______ genetic variation • Genetic variation is important because_________ Chance Founder effect Bottle necks Small decrease Some can survive in case of an environmental change
Reproductive Isolation X Cannot make a fertile baby= different species mule Geographic isolation= Physically separated
Mrs. Workman,do you have evidence of Evolution? 1. 2. 3. 4. 5. 6. Fossil evidence-level in strata and carbon dating Homologous structures-same structures for different functions because common ancestor, whale flipper and human arm Vestigial Structures-no longer has the use it had in an ancestor. Ex human tail bone, pelvis in snakes Comparative embryology-comparing development DNA or RNA homology-comparing DNA, more similar=more recent common ancestor Biogeography- where organisms located because developed in isolation
Biodiversity • The variety of species living within an ecosystem
Ecosystems • Ecosystems consist of a given area’s physical features (__________ ) and organisms (__________) • Organisms that live together in an ecosystem are called a __________ • Abiotic factors • Biotic factors • community
Population • A group of organisms that all belong to the same species and • live in a given area • What is a population?
When you alter an environment in any way, you alter everything that is somehow attached. Everything in an ecosystem is connected!
Producers & Consumers Sheep Shrimp
Decomposers • Which one is a decomposer? Why are decomposers important for a healthy ecosystem? The Earth would be one big pile of dead things!
Food Pyramid (Food Chain) • Identify: • The producers • The consumers • The autotrophs
Food Webs • Nature really more like a web, not a chain.
Predation One species eats the other species (predator-prey)
1% 10% 10% 10% Energy Pyramid Energy • A consumer eats another organism to obtain ________. • It gets only ________ by doing this. 10% 90% Given off 90% Given off 90% Given off 99% Given off