The Work of Gregor Mendel

The Work of Gregor Mendel http://sps.k12.ar.us/massengale/genetics%20tutorial.htm http://www.jic.bbsrc.ac.uk/germplas/pisum/zgs4f.htm

parents to offspring heredity Transmission of characteristics from _______________________is called ___________________. The _________ that studies _____ those characteristics are _________ from one generation to the next is called ___________________ how SCIENCE passed on Genetics

http://www.jic.bbsrc.ac.uk/germplas/pisum/zgs4f.htm Father of Genetics The __________________ is _________________, a monk whose _________ of genetic traits was the beginning of our _________________ about _____________________. Gregor Mendel study understanding how genes work

pair of FACTORS control Mendel decided that there must be a __________________ that ________each trait and that __________ must be able to _______ the other. one factor HIDE

We now know that Mendel’s ________________ carried on the pair of________________ _________________ factors are genes homologous chromosomes http://www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif

DIFFERENT ________ gene _______ for a trait are called ___________. CHOICES ALLELES http://sps.k12.ar.us/massengale/genetics%20tutorial.htm

DOMINANT HIDES __________________ = An allele that ________ the presence of another allele __________________ = An allelethat __________________ the presence of another allele RECESSIVE is hidden by

PROBABILITY ____________________is the __________ that a particular _________________ likelihood event will occur It can be written as a: Fraction ____ Percent ____ Ratio ____ 1/4 25% 1:3

http://www.arborsci.com/CoolStuff/CoinFlip.jpg COIN FLIP There are 2 possible outcomes: HEADS TAILS The chance the coin will land on either one is: ____ ____ ____ Alleles segregate randomly just like a coin flip. . . So can use probability to predict outcomes of genetic crosses. 1/2 50% 1:1

PROBABILITIES PAST DON’T FUTURE If last coin flip was heads… there is still a 50/50 chance the next flip will be heads too. _____ outcomes ______ affect _________ones _____________works ______ in ___________ a ________ number of events. Probability predicting best large The more flips. . . The closer results will be to the expected 50:50 average.

DOMINANT/RECESSIVE Dominant capital _____________ allele is represented by a ____________ letter.(usually the first letter of the trait) ____________ allele is represented by the SAME _________________ letter. EX: Tall = ______ Short =______ Recessive lower-case T t NOT S for short

HOMOZYGOUSHETEROZYGOUS When both alleles in the pair are the _______, the organism is _______________ or __________ EX: ____ or ___ When both alleles in the pair are _____________, the organism is _________________ or _____________ Ex: ____ SAME HOMOZYGOUS PURE TT tt DIFFERENT HETEROZYGOUS HYBRID Tt

PHENOTYPE/GENOTYPE genetic makeup The ________________ of an organism is its _____________ The ____________of an organism is its _____________ GENOTYPE appearance PHENOTYPE

PUNNETT SQUARES are used to show possible offspring from a cross between 2 parents _______________ go at top and on left side Boxes show _______________________________ Parent alleles T T TT TT Tt Tt T t possible offspring combinations

GENES are more complicated than Mendel thought ENVIRONMENT influences ____________________________ the ________________________. = ________________________ Genes ________ the ______ for development, but how plan unfolds also _______ on ______________conditions. expression of genes “Nature vs Nurture” provide plan depends environmental

GENES are more complicated than Mendel thought Some traits have ____________ allele __________ = ____________________ EX: Eye color Allele choices ___ ___ ___ choices MORE than 2 MULTIPLE ALLELE TRAIT Blue Brown Green

GENES are more complicated than MENDEL thought Some traits are determined by ____________________________ = __________________ EX: human height. intelligence, skin & eye color MORE THAN ONE GENE POLYGENIC TRAIT http://www.bcps.org/offices/lis/models/life/images/grow.JPG

GENES are more complicated than MENDEL thought MORE than ONE gene Traits determined by ____________ _________ have _____“___________” phenotypes many in-between There aren’t just SMART people and DUMB people…. there is a ________________ of intelligences in-between whole range

GENES are more complicated than MENDEL thought KINDS OF DOMINANCE ____________________ ____________________ ____________________ COMPLETE DOMINANCE INCOMPLETE DOMINANCE CO-DOMINANCE

COMPLETE DOMINANCE Dominant masks recessive __________ allele _______ the ___________ one PATTERN ?____________ allele ________ in a _____ratio in the ____ generation Recessive returns 3:1 F2 http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

INCOMPLETE DOMINANCE DON’T SEE __________ expected _____ ratio in F2 generation _____________ organisms with one dominant and one recessive allele show a _________ in-between trait 3:1 Heterozygous BLENDED Image modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

CO-DOMINANCE BOTH SAME TIME NO BLENDING _______ traits are expressed at ___________ (_____________________) in heterozygote ROAN A ________HORSE has ______________ hair and __________ hair side by side BOTH RED WHITE

CO-DOMINANCE Both traits are expressed together (NO BLENDING) in heterozygote Persons with an A alleleAND a B allele have blood type AB

BLOOD TYPES have more than 2 allele choices= _________________________ MULTIPLE ALLELE TRAIT The pattern of sugars that is attached is determined by genes Allele choices are: _____ ____ ____ A B O

A and B are CO-DOMINANT A cell with BOTH an A and a B allele has BOTH “A” and “B”

The Work of Gregor Mendel