Heredity (B) -2013 Heredity (B) -2013

KAREN LANCOURKAREN LANCOUR HEREDITY HEREDITY

NATIONAL SUPERVISORNATIONAL SUPERVISORkarenlancour@charter.net

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