heredity (b) -2013
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Heredity (B) -2013. KAREN LANCOUR HEREDITY NATIONAL SUPERVISOR [email protected]. Event Rules – 2013. DISCLAIMER - PowerPoint PPT PresentationTRANSCRIPT
Heredity (B) -2013 Heredity (B) -2013
KAREN LANCOURKAREN LANCOUR HEREDITY HEREDITY
NATIONAL SUPERVISORNATIONAL [email protected]
Event Rules – 2013 Event Rules – 2013
DISCLAIMERThis presentation was prepared using draft rules. There may be some changes in the final copy of the rules. The rules which will be in your Coaches Manual and Student Manuals will be the official rules.
Event Rules – 2013 Event Rules – 2013
BE SURE TO CHECK THE 2013 EVENT RULES FOR EVENT PARAMETERS AND TOPICS FOR EACH COMPETITION LEVEL
TRAINING MATERIALSTRAINING MATERIALS Training Power Point – content overview Training Handout - content information Sample Tournament – sample problems with key Event Supervisor Guide – prep tips, event needs,
and scoring tips Internet Resource & Training CD’s – on the
Science Olympiad website at www.soinc.org under Event Information
Biology-Earth Science CD, Genetics CD (new) Genetics CD (new) for Heredity and Designer Genes as well as the Division B and Division C Test Packets are available from SO store at www.soinc.org
Heredity (B) ContentContent
Basic principles of genetics Some possible areas – dominant,
recessive, incomplete dominance, co-dominance, monohybrid & dihybrid crosses, test cross, multiple alleles, sex-linkage, genotype, phenotype, epistasis, mutations, multifactorial traits, pedigrees, karyotypes, mitosis, meiosis, nondisjunction, genetic disorders, DNA structure and replication, transcription, translation, common genetic disorders
Process SkillsProcess Skills – data analysis, predictions, calculations, inferences, observations
Possible Topics for Various Levels
Regional & State Regional & State National (all topics)
Monohybrid cross Dihybrid cross Pedigree construction and analysis
Dominant and recessive alleles
Sex-linked traits Production of gametes with Abnormal #’s of chromosomes
Genotype vs. phenotype Pedigree analysis Trihybrid cross (probability analysis)
Human sex determination Multiple alleles Analysis of karyotypes for deletion,
addition, translocation
Gene: protein relationship DNA structure & replication
Transcription and translation
Mitosis Meiosis and gamete formation
Multifactorial traits
Human karyotypes analysis for nondisjunction disorders
Co-dominance &Incomplete Dominance
Epistasis
PRINCIPLES OF PRINCIPLES OF GENETICS GENETICS GENESGENES – come in pairs
Section of DNA – codes protein or part of protein
One from each parent
ALLELEALLELE – different forms of a gene MULTIPLE ALLELES MULTIPLE ALLELES – more than 2 forms
of a gene HOMOZYGOUSHOMOZYGOUS – same alleles HETEROZYGOUSHETEROZYGOUS – different alleles
Dominant vs. Recessive Dominant vs. Recessive DominantDominant – always
expressed Capital letters – N Homozygous - NN Heterozygous - Nn
RecessiveRecessive – prevented by dominant
Lower case letters – n Homozygous – nn
Punnett Square – Box showingallele combinations
Dominant and Dominant and RecessiveRecessive Autosomal DominantAutosomal Dominant
Dominant gene on an autosomeDominant gene on an autosome Autosomal RecessiveAutosomal Recessive
Recessive gene on an autosome Recessive gene on an autosome Sex-linked DominantSex-linked Dominant
Dominant gene on a sex chromosomeDominant gene on a sex chromosome Sex-linked RecessiveSex-linked Recessive
Recessive gene on a sex chromosomeRecessive gene on a sex chromosome
Monohybrid Cross Monohybrid Cross
HybridHybrid – Ss X Ss
One TraitOne Trait – Smooth vs wrinkled
Two gametes per Two gametes per parentparentS and s
Punnett SquarePunnett Square with 4 boxes – 4 offspring
Genotype & Phenotype Genotype & Phenotype
GenotypeGenotype PhenotypePhenotype SS or Ss Round ss Wrinkled
Genotype frequencyGenotype frequency 1:2:1
Phenotype frequencyPhenotype frequency 3:1
DihybridDihybrid Cross Cross
DihybridDihybrid – 2 traits
Gametes per parentGametes per parent = 4
Punnett SquarePunnett Square – 16 boxes
Genotype ratioGenotype ratio 1:2:1:2:4:2:1:2:1
Phenotype ratioPhenotype ratio 9:3:3:1
Incomplete DominanceIncomplete Dominance HybridHybrid is a blend of
two traits Genotype Genotype
frequencyfrequency1:2:1
Phenotype Phenotype frequencyfrequency
1:2:1 ExamplesExamples:
Flowers, Animal fur
Co-dominance Co-dominance More than one dominant More than one dominant
alleleallele Blood types – Blood types – A,B,O allelesA,B,O alleles Phenotypes GenotypesPhenotypes Genotypes
A I AI A or I Ai B IBIB or IBiAB I AIB
O ii
Co-dominance
co-dominanceco-dominance – both dominant alleles (genes) in an individual are expressed as blood types
A and B genes are co-dominant and both dominant over the O gene which is recessive
ABO Blood System ABO Blood System
Independent Independent Assortment Assortment vs. vs. Linkage Linkage
Independent AssortmentIndependent Assortment – genes on different chromosomes separate independently during meiosis
LinkageLinkage – genes on the same chromosome are inherited as a group Autosomal linkageAutosomal linkage – on – on
autosomesautosomes Sex-linkedSex-linked – on sex – on sex
chromosomeschromosomes
Linkage – Sex LinkageLinkage – Sex Linkage
LinkageLinkage – genes on the same chromosome inherited as a group
Sex-linkageSex-linkage – genes on sex chromosomes (esp. X)
Y-chromosome shorterY-chromosome shorter – some genes from X missing
X-linked traitsX-linked traits more common in men
Men get X-chromosome from mom Red-green colorblindness,
hemophilia
Environmental Environmental influence on genes influence on genes expression expression Gene function is influenced by
environment as with identical twins
Genes have blueprint for proteins or parts of proteins
Proteins can be structural proteins (parts of body) or functional proteins (hormones/enzymes)
Epistasis and Epistasis and Multifactorial Multifactorial Inheritance Inheritance
Epistasis - the interaction between two or more genes to control a single phenotype
Multifactorial inheritance - many factors (multifactorial) both genetic and environmental are involved in producing the trait or condition. Examples: height, weight, cleft palate, spina bifida
Pedigree Symbols Pedigree Symbols
GenerationsGenerations = I – Original Parents, II- F1 (children), III – F2 (grandchildren)
Pedigree – Curly vs Pedigree – Curly vs Straight Hair Straight Hair
Types of AnalysisTypes of Analysis Relationships Relationships Dominant GeneDominant Gene – H – H
CurlyCurly Recessive GeneRecessive Gene – h – h
Straight Straight Genotypes Genotypes PhenotypesPhenotypes
KaryotypesKaryotypes Pairs 1-22Pairs 1-22
=Autosomes XYXY = Sex chromosomes MaleMale = X & Y FemaleFemale = only X NondisjunctionNondisjunction Extra chromosomesExtra chromosomes
(Trisomy)(Trisomy) Missing Missing
chromosomeschromosomes(Monosomy)(Monosomy)
Cell Cycle Cell Cycle
InterphaseInterphase G1G1 S – DNA S – DNA
replicatesreplicates G2G2
MitosisMitosis ProphaseProphase MetaphaseMetaphase AnaphaseAnaphase Telophase Telophase
Mitosis vs Meiosis Mitosis vs Meiosis
MitosisMitosis Growth and Asexual Reproduction One division – 2 diploid cells Genetically same as original
MeiosisMeiosis Gametes for Sexual Reproduction 2 divisions – 4 haploid cells
DNA Structure DNA Structure Double helixDouble helix Antiparallel Antiparallel – 3’ to
5’ NucleotideNucleotide
Deoxyribose sugar Phosphate Nitrogen bases
Adenine Thymine Guanine Cytosine
DNA DNA Replication Replication
ReplicationReplication (in nucleus)
DNADNA uncoils & splits
ReadsReads 3’ to 5’ AssemblesAssembles 5’ to 3’ 4 types4 types of
nucleotides OkazakiOkazaki fragments
Types of RNA Types of RNA
Differences between DNA & RNADifferences between DNA & RNA Single strand Ribose instead of Deoxyribose Uracil instead of Thymine
Messenger RNAMessenger RNA – carries blueprint Transfer RNATransfer RNA – brings amino acids Ribosomal RNARibosomal RNA – reads code
Transcription & Transcription & TranslationTranslation
TranscriptionTranscription – makes RNA (in nucleus)
Translation (protein synthesis) Translation (protein synthesis) -Reads blueprint and makes protein or part of protein (in cytoplasm at the ribosome)
Transcription of RNA Transcription of RNA from DNAfrom DNA
Transcription: Synthesis of RNA from a DNA Template. Requires DNA-dependent RNA polymerase plus the
four nucleotides (ATP, GTP. CTP and UTP). Synthesis begins at a the initiation site on DNA The template strand is read 3' to 5' and the mRNA is
synthesized 5' to 3'
Translation – Protein Translation – Protein Synthesis Synthesis
Mutations Mutations
MutationMutation – any change in the DNA
Gene mutationGene mutation Chromosomal mutationChromosomal mutation Agents causing mutationsAgents causing mutations –
radiation, chemicals, excess heat