9-1 How come you look like you? http://www.jic.bbsrc.ac.uk/germplas/pisum/zgs4f.htm It’s in your genes!

Transmission of characteristics from parents to offspring is called ___________________. The STUDY of how those characteristics are passed on from one generation to the next is called ___________________ heredity Genetics

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

Mendel designed experiments using _________________________. He looked at different observable CHARACTERISTICS or ______________ Pea plants TRAITS

Pea Characteristics http://mac122.icu.ac.jp/BIOBK/BioBookgenintro.html

A plant that ALWAYS produces offspring with a certain trait are called ___________ for that trait. PURE

Remember all body cells have 2 copies of every gene, so to breed pure the 2 parent gene choices must be the_________. SAME red flower alleles TWO

PURE white flowered plants have ______ WHITE flower alleles TWO

Mendel combined genes from 2 PURE parent plants and recorded the kinds of ___________ produced. In his experiments the 1st plants crossed were called the ____ generation. ( P is for parental) offspring P1

GENETIC EXPERIMENTS P1 ____ generation (parental) ____ generation (filial=offspring) ___ generation F1 F2

GENETIC EXPERIMENTS Image modified from: http://www.laskerfoundation.org/rprimers/gnn/timeline/1866.html http://www.accessexcellence.org/AB/GG/mendel.html

When Mendel crossed PURE PLANTS with 2 choices for a trait: He found 1. ___________________________________ BUT 2. ___________________________________ Only one trait showed in the F1 generation Missing trait reappeared in the F2 generation in a 3 to 1 ratio

Mendel decided that there must be a_______ of “factors” controlling each trait and that one factor must be able to _______ the other. pair hide

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

_______________ are different gene choices for a trait. ALLELES

DOMINANT __________________ = An allele that MASKS the presence of another allele __________________ = An allele that IS MASKED BY the presence of another allele RECESSIVE

WHAT DOES MEIOSIS HAVE TO DO WITH IT?

MENDEL’S LAWS SEGREGATION LAW OF ____________________ The pair of factors is segregated (or separated) during the formation of gametes. SEGREGATION Image modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif

LAW OF __________________________ the factors are distributed to gametes independently of other factors INDEPENDENT ASSORTMENT Image modified from: http://anthro.palomar.edu/mendel/mendel_1.htm

MEIOSIS MENDEL’s LAWS of SEGREGATION & INDEPENDENT ASSORTMENT happen because of the way the chromosomes move during __________________ MEIOSIS http://www.tokyo-med.ac.jp/genet/anm/mimov.gif

GENETIC CROSSES 9-2

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

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

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

Animation from: http://www.people.virginia.edu/~rjh9u/monohyb.html PUNNETT SQUARES are used to show possible offspring of a cross between 2 parents Parent genes go at top and on left side Boxes show possible combinations

PROBABILITY ____________________ is the likelihood that a specific event will occur It can be written as a: Fraction 1/4 Percent 25% Ratio 1:3

IN PEA PLANTS Tall is dominant over short TALL = ____ SHORT = ____ T t

PURE TALL parent What genes can it give? T T _________ HOMOZYGOUS   T T

T T

PURE SHORT parent What genes can it give? t t _________ HOMOZYGOUS   t t

T T t t T t T t T t T t ALL of the offspring 4/4 100% will be Tt TALL GENOTYPE _____ PHENOTYPE _______

HYBRID TALL parent What genes can it give? T t _________ HETEROZYGOUS   T t

T t

T t T t T t T T T t t t GENOTYPES ¼ = _____ TT ½ = _____ Tt tt 3/4 1/4 TALL PHENOTYPES _______ ____________ _______ ____________ 1/4 SHORT

MAKING A CROSS with only ONE gene trait = ____________________ MONOHYBRID CROSS A Punnett square for a MONOHYBRID CROSS looks like this:

TESTCROSS used to tell what genes an organism has Cross an UNKNOWN parent with a ____________________________ and see results Offspring give a clue about the unknown parent’s genes HOMOZYGOUS RECESSIVE

TESTCROSS used to tell what genes an organism has Example: The genes of a TALL PARENT are UNKNOWN - COULD HAVE _____ TT Tt http://mac122.icu.ac.jp/BIOBK/BioBookgenintro.html

TESTCROSS Tt tt t Tt Tt 50% will be TALL All offspring will 50% will be SHORT All offspring will be TALL

DEAF DOGS Deafness in dogs is caused by a recessive allele. Deaf dogs have the genotype dd. A HEARING dog could have 2 possible GENOTYPES ______ ______ How do we tell which one it is? Dd DD

TESTCROSS DEAF PARENT WITH PURE HEARING PARENT D D D d d Hear Hear Hear Deaf Hear Deaf d If you get some deaf puppies, you know parent was Dd.

GENES are more complicated than MENDEL thought Some traits have more than two allele choices EX: eye color

GENES are more complicated than MENDEL thought Some traits are determined by more than one gene EX: Human height http://www.bcps.org/offices/lis/models/life/images/grow.JPG

GENES are more complicated than MENDEL thought Traits determined by more than one gene have lots of “in-between” phenotypes There aren’t just SMART people and DUMB people…. there is a whole range of intelligences in-between http://www.newtonswindow.com/problem-solving.htm

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

COMPLETE DOMINANCE Dominant allele masks the recessive one Recessive allele returns in a 3:1 ratio in the F2 generation

INCOMPLETE DOMINANCE Don’t see expected 3:1 ratio in F2 generation Organisms with one dominant and one recessive allele show a blended in-between trait

INCOMPLETE DOMINANCE ALLELES BLEND to produce an INTERMEDIATE PHENOTYPE Don’t see the expected 3:1 ratio in the F2 generation

CO-DOMINANCE Both traits are expressed at same time (NO BLENDING) in heterozygote Has BOTH RED hair and WHITE hair

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

BLOOD TYPES have more than 2 allele choices Proteins with SUGARS attached help cells recognize ___________ Called _______________ “self” GLYCOPROTEINS http://www.mannanw.com/super-sugars.htm

BLOOD TYPES have more than 2 allele choices The protein and sugar that is attached is determined by genes Allele choices are: _____ ____ ____ B A O

BLOOD TYPES An A gene tells the cell to put “A” glycoproteins on its surface

BLOOD TYPES An B gene tells the cell to put a different “B” glycoprotein on its surface

BLOOD TYPES An O gene tells the cell NOT to put anything on the surface

A and B are CO-DOMINANT A cell with an A and a B gene has BOTH glycoproteins on its surface

BLOOD TYPES & ALLELES ALLELE BLOOD TYPE AA A AO BB B BO OO O AB

BLOOD TYPES IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME! YOU ARE NOT ME! IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME! Body images modified from: http://www.new-fitness.com/images/body_shapes.jpg

BLOOD TYPES IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME! YOU ARE NOT ME! IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME! Body images modified from: http://www.new-fitness.com/images/body_shapes.jpg

BLOOD TYPES YOU’RE LIKE ME! IMMUNE SYSTEM ATTACKS! YOU ARE NOT ME! IMMUNE SYSTEM ATTACKS! YOU’RE LIKE ME! Body images modified from: http://www.new-fitness.com/images/body_shapes.jpg

BLOOD TYPES YOU’RE NOT DIFFERENT FROM ME! O can donate to EVERY BLOOD TYPE = UNIVERSAL DONOR! Nothing on surface to recognize as “NOT SELF” YOU’RE NOT DIFFERENT FROM ME! Body images modified from: http://www.new-fitness.com/images/body_shapes.jpg

BLOOD TYPES AB can RECEIVE FROM EVERY BLOOD TYPE = UNIVERSAL RECIPIENT Body image modified from: http://www.new-fitness.com/images/body_shapes.jpg

BLOOD TYPE FREQUENCY IN USA 40% B 10% AB 4% O 46% http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/BldTyping.html

OTHER BLOOD TYPES Rh+ Rh-

OTHER BLOOD TYPES NO PROBLEMS IF: MOM is + & BABY is - MOM & BABY are both + Imagea modified from: http://www.wsd1.org/lessonplans/images/Body.gif

OTHER BLOOD TYPES PROBLEMS IF: MOM is - & BABY is + 1st baby OK but few baby cells entering mom’s bloodstream put mom’s immune system on alert for + cells. Next + baby, mom’s immune system can attack baby as it is growing Shot after 1st birth prevents alert Imagea modified from: http://www.wsd1.org/lessonplans/images/Body.gif

DIHYBRID CROSSES (2 traits) http://mac122.icu.ac.jp/BIOBK/BioBookgenintro.html

MAKING A CROSS with TWO gene traits = ____________________ DIHYBRID CROSS A Punnett square for a DIHYBRID CROSS looks like this:

HOMOZYGOUS ROUND YELLOW HOMOZYGOUS WRINKLED GREEN X r r y y R R Y Y

POSSIBLE GAMETES?

POSSIBLE GAMETES?

RY RY RY RY RrYy ROUND YELLOW ry ry ry ry RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RY RY RY RrYy 100% of offspring = _______ genotype _______________________ phenotype ROUND YELLOW

HETEROZYGOUS ROUND YELLOW X R r Y y R r Y y

POSSIBLE GAMETES?

9:3:3:1 9 RY 3 ry 3 rY Ry Sign of a heterozygous dihybrid cross is a ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RY RRYY RrYy RrYY RRYy RrYy rryy rrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy RRyy 3 ry 3 rY 1 Ry Sign of a heterozygous dihybrid cross is a _____________ ratio in offspring. 9:3:3:1

9:3:3:1 9 3 3 1 ____ DOMINANT TRAIT 1 ; DOMINANT TRAIT 2 ____ DOMINANT TRAIT 1; RECESSIVE TRAIT 2 ____ RECESSIVE TRAIT 1; DOMINANT TRAIT 2 ____ RECESSIVE TRAIT 1; RECESSIVE TRAIT 2 3 3 1 9:3:3:1