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BILL PUNNETT PRACTICE. Kelly Riedell Brookings Biology. Image from: https://biologydictionary.net/wp-content/uploads/2016/11/Punnett-Square.png. Image from: https://blissbiology.files.wordpress.com/2015/04/10-04.gif. MENDELIAN GENETICS. Y. Y. y. Y y Y y Y y Y y. Y y. Yellow.
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BILL PUNNETT PRACTICE Kelly RiedellBrookings Biology Image from: https://biologydictionary.net/wp-content/uploads/2016/11/Punnett-Square.png
Image from: https://blissbiology.files.wordpress.com/2015/04/10-04.gif MENDELIAN GENETICS
Y Y y Yy Yy Yy Yy Yy Yellow y HOMOZYGOUS MONOHYBRID (1 gene) CROSSES: PURE-BREEDING YELLOW SEED parent X PURE-BREEDING GREEN SEED parent POSSIBLE OFFSPRING GENOTYPEPHENOTYPE_______ _____________ What is the probability an offspring will show the DOMINANT TRAIT (YELLOW SEEDS)? ________ What is the probability an offspring will show the RECESSIVE TRAIT (GREEN SEEDS)? ________ 100% ; 4/4; 4:0 0% ; 0/4; 0:4
P P p Pp Pp Pp Pp Pp Purple flower p HOMOZYGOUS PURPLE FLOWER plant X HOMOZYGOUS WHITE FLOWER plant POSSIBLE OFFSPRING GENOTYPEPHENOTYPE_______ _____________ What is the probability an offspring will show the DOMINANT TRAIT (PURPLE FLOWERS)? ________ What is the probability an offspring will show the RECESSIVE TRAIT (WHITE FLOWERS)? ________ 100% ; 4/4; 4:0 0% ; 0/4; 0:4
T T t Tt Tt Tt Tt Tall Tt t HOMOZYGOUS TALL plant X PURE-BREEDING SHORT plant POSSIBLE OFFSPRING GENOTYPEPHENOTYPE_______ _____________ What is the probability an offspring will show the DOMINANT TRAIT (TALL)? ________ What is the probability an offspring will show the RECESSIVE TRAIT (SHORT)? ________ 100%; 4/4; 4:0 0% ; 0/4; 0:4
100 RECESSIVE SEE A PATTERN FOR HOMOZYGOUS MONOHYBRID CROSSESIf you cross plants that are HOMOZYGOUS DOMINANT with plants that are HOMOZYGOUS RECESSIVE for a trait, _______ % of the offspring will show the DOMINANT trait and the ______________ trait will not show at all. ***************************************************************** USE THE PATTERN ABOVE TO MAKE A PREDICTION ABOUT A CROSS WITHOUT A PUNNETT: If you cross a HOMOZYGOUS ROUND SEED plant with a PURE WRINKLED SEED plant 100% of the offspring will look _________ 0% of the offspring will look ____________ The offspring will have 100% probability of having the_______ genotype. ROUND WRINKLED Rr
b B B BB Bb Bb bb BB Black b Bb Black bb Brown HETEROZYGOUS MONOHYBRID CROSSES A black coat (B) is DOMINANT in guinea pigs. A brown coat (b) is RECESSIVE. Make a cross between TWO HETEROZYGOUS BLACK guinea pigs. POSSIBLE OFFSPRING GENOTYPEPHENOTYPE _________ _________________ _________ _________________ __________ ___________________ What is the probability that an offspring will be: black? _________ brown? _________ a HYBRID? ________ HOMOZYGOUS DOMINANT ? _________ HOMOZYGOUS RECESSIVE? ___________ 75%; ¾; 3:1 25%; ¼ ; 1:3 50%; ½ ; 2:2 25%; ¼ ; 1:3 25%; ¼ ; 1:3
p P P PP Pp Pp pp Purple PP p Purple Pp Yellow pp HETEROZYGOUS MONOHYBRID CROSSES Purple fur (P) is DOMINANT in monsters. Yellow fur (p) is RECESSIVE. Make a cross between TWO HETEROZYGOUS PURPLE MONSTERS. . POSSIBLE OFFSPRING GENOTYPEPHENOTYPE _________ _________________ _________ _________________ __________ ___________________ What is the probability that an offspring will be: PURPLE? _________ YELLOW ? _________ a HYBRID? ________ HOMOZYGOUS DOMINANT ? _________ HOMOZYGOUS RECESSIVE? ___________ 75%; ¾; 3:1 25%; ¼ ; 1:3 50%; ½ ; 2:2 25%; ¼ ; 1:3 25%; ¼ ; 1:3
t T TT Tall T Tt Tall TT Tt Tt tt short tt t HETEROZYGOUS MONOHYBRID CROSSESMake a cross between TWO HETEROZYGOUS TALL pea plants POSSIBLE OFFSPRING GENOTYPEPHENOTYPE _________ _________________ _________ _________________ __________ ___________________ What is the probability that an offspring will be: TALL? _________ SHORT? _________ a HYBRID? ________ HOMOZYGOUS DOMINANT ? _________ HOMOZYGOUS RECESSIVE? ___________ 75%; ¾; 3:1 25%; ¼ ; 1:3 50%; ½ ; 2:2 25%; ¼ ; 1:3 25%; ¼ ; 1:3
3 1 75 25 DOMINANT RECESSIVE DOMINANT RECESSIVE SEE A PATTERN FOR HETEROZYGOUS MONOHYBRID CROSSES: If you cross 2 parent plants that are BOTH HETEROZYGOUS for a trait the offspring will show a __ : __ phenotypic ratio (DOMINANT:RECESSIVE)_____ % of the offspring will show the DOMINANT trait and____ % of the offspring will show the RECESSIVE trait. USE DOMINANT OR RECESSIVE TO FILL IN THE BLANKS BELOW:¼ of the offspring will have two _____________ alleles, ½ will be hybrids with one ______________ and one ______________ allele, and ¼ will have two _______________ alleles. *****************************************************************u
ROUND WRINKLED RR Rr rr USE THE PATTERN ABOVE TO MAKE A PREDICTION ABOUT A CROSS WITHOUT A PUNNETT: If you cross two HETEROZYGOUS ROUND SEED plants 75% will LOOK ________ 25% will LOOK _________ The probability is:¼ will have the genotype ______ ½ will have the genotype _____ ¼ will have the genotype _____
ry ry ry ry RY RY RY RY MAKING HOMOZYGOUS TWO GENE CROSSES:HOMOZYGOUS ROUND & YELLOW X PURE-BREEDING WRINKLED & GREEN Parent genotype _____________ ____________ Possible gametes ____ ____ ____ ____ ____ ____ ____ ____ RRYY rryy RY RY RY RY ry ry ry ry RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy RrYy
16/16 0/16 0/16 0/16 WHAT IS THE PROBABILITY AN OFFSPRING WILL BE: _______ ROUND & YELLOW _______ WRINKLED & YELLOW _______ ROUND & GREEN _______ WRINKLED & GREEN ********************************************************* SEE A PATTERN FOR HOMOZYGOUS TWO GENE CROSSES: If you cross plants that are PURE DOMINANT for TWO TRAITS with plants that are PURE RECESSIVE for TWO TRAITS, ________ % of the offspring will look DOMINANT for BOTH traits and the TWO ______________ traits will not show at all. 100 RECESSIVE
RrYy __________________ RY Ry ry rY
RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green RRYY RRYy RrYY RrYy RRYy RRyy RrYy RryyRrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy
RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RRYY RRYyRrYYRrYy RRYyRRyyRrYyRryyRrYYRrYyrrYYrrYy RrYyRryyrrYyrryy .
RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RRYY RRYyRrYYRrYy RRYyRRyyRrYyRryyRrYYRrYyrrYYrrYy RrYyRryyrrYyrryy 3
RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RRYY RRYyRrYYRrYy RRYyRRyyRrYyRryyRrYYRrYyrrYYrrYy RrYyRryyrrYyrryy 3 3
RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RRYY RRYy RrYY RrYy RRYyRRyy RrYy RryyRrYY RrYy rrYY rrYy RrYy Rryy rrYyrryy 3 3 1
9 ____ ____________ TRAIT 1 ; ____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 dominant dominant 3 dominant recessive 3 recessive dominant 1 recessive recessive __________ratio is a clue that it’s a ____________________________cross 9:3:3:1 HETEROZYGOUS TWO gene
USE THE PATTERN TO MAKE A CROSS WITHOUT A PUNNETT CROSS TWO HETEROZYGOUS ROUND & PURPLE parents The probability is :9/16 will be _________________ & _________________3/16 will be _________________ & _________________3/16 will be _________________ & _________________1/16 will be _________________ & _________________ round purple round white wrinkled purple wrinkled white
Image from: https://biologydictionary.net/wp-content/uploads/2016/11/Punnett-Square.png NON-MENDELIAN GENETICS - Sex-linked traits
COMPLETE DOMINANCE Dominant allele completely masks the recessive one. PATTERN ?F1- All show ___________ phenotype F2- __________ trait returns In a _____ratio Dominant Recessive 3:1 http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
INCOMPLETE DOMINANCE Heterozygous EX: SNAPDRAGONS _______________ organisms with one dominant and one recessive allele show a ____________ in-between trait BLENDED Image modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
W R R RR RW RW WW RR Red flowers 25% W 50% RW Pink flowers White flowers 25% WW HETEROZYGOUS INCOMPLETELY DOMINANT SNAPDRAGON PLANTS In snapdragons, red flowers (R) is INCOMPLETELY DOMINANT to white flowers (W)Make a cross between TWO HETEROZYGOUS snapdragon plants. POSSIBLE OFFSPRING PROBABILITY GENOTYPEPHENOTYPE _________ ______ _______________ _________ ________ __________________ __________ __________ ___________________
CODOMINANCENO ____________. BOTH ALLELES show together at the ____________ at the same time. BLENDING SIDE BY SIDE. In chickens, alleles for BLACK (B) and WHITE (W) color are CODOMINANT. Heterozygous chickens with BWshow a speckled (ERMINETTE) phenotype. BB WW BW
W B B BB BW BW WW BB Black 25% W Erminette (black & white) BW 50% 25% WW HETEROZYGOUS INCOMPLETELY DOMINANT Black chickens (B) is INCOMPLETELY DOMINANT TO white chickens (W)Make a cross between TWO HETEROZYGOUS ERMINETTE chickens. POSSIBLE OFFSPRING PROBABILITY GENOTYPEPHENOTYPE _________ ______ _______________ _________ ________ __________________ __________ __________ ___________________ White
CO-DOMINANCE Both traits are expressed together (NO BLENDING) in heterozygote Persons with an IA alleleAND a IB allele have blood type AB
http://www.mannanw.com/super-sugars.htm GLYCOPROTEINS Membrane proteins with sugars attached that help cells recognize self = ____________________ Responsible for blood type Multiple allele trait =more than 2 choices_____ _____ _____ A B O i IA IB
BLOOD TYPES & ALLELES A B AB O IA i _____ allele is dominant to _____ allele._____ allele is dominant to _____ allele._____ and _____ are CODOMINANT BOTH SHOW TOGETHER i IB IA IB
i IB IA IB IA i IB i i i IA i POSSIBLE OFFSPRING PROBABILITY GENOTYPEPHENOTYPE (BLOOD TYPE) _________ ________ _______ _________ _________ _______ __________ _________ _______ __________ _________ ________ MOM with IA i genotype X DAD with IB i genotype AB 25% IA IB A IA i 25% 25% B IB i 25% O i i
IB IB IA IB IA IB IB i IB i IA i POSSIBLE OFFSPRING PROBABILITY GENOTYPEPHENOTYPE (BLOOD TYPE) _________ ________ _______ _________ _________ _______ MOM with IAi genotype X DAD with IB IB genotype AB 50% IA IB B IB i 50%
IA IA IB IA i IB IA IB IA i IB i i i IA IB IA IB IB i IB i i i Wanda thinks either Ralph or Fred could be the father of her baby. Wanda’s genotype is IAi. Wanda’s baby has type O blood. Ralph’s genotype is IAIB. Fred’s genotype is IB i. Ralph X Wanda Fred X Wanda IS IT POSSIBLE RALPH IS THE FATHER? YES NO IS IT POSSIBLE FRED IS THE FATHER? YES NO DOES IT PROVE IT’S FRED? YES NO ANYONE WITH AN i ALLELE COULD BE THE DAD
Image from: https://biologydictionary.net/wp-content/uploads/2016/11/Punnett-Square.png NON-MENDELIAN GENETICS - Sex-linked traits
http://www.angelbabygifts.com/ Sex chromosomes autosomes Chromosomes that determine the sex of an organism = _________________ All other chromosomes = _________________ Humans have two sex chromosomes ___ and ___ and _____ autosomes Females = _____ Males = _____ X y 44 XX Xy
Who decides sex of baby?Mom can only give X Dad can give X or y X X X XXX X y X y X y Dad SO ____ determines sex of the baby. If dad gives X with mom’s X =______If dad give y with mom’s X = ______ girl boy
SEX-LINKED GENES Y-linked genes:▪ Hairy pinna ▪ SRY- master gene that turns on other genesActivation cascade makes developing embryo MALE X-linked genes (X-linked recessive disorders) ▪ Blood clotting factors (Hemophilia)▪ Eye color receptors (Color blindness)▪ Muscle proteins (Duchenne Muscular Dystrophy) MALES X-linked traits show up more frequently in ________ No backup X to cover for the “broken” gene Pass mutation to __________ Females can show trait if they inherit _____ mutant X’s Can be _________ for X-linked traits. _______ get mutation from MOM DAUGHTERS TWO CARRIERS SONS
X-LINKED RECESSIVE CROSS Colorblind male X normal vision (non-carrier) female Xc Y Pattern depends on whichparent has the mutation! XCXc XCY XCXc XCY XC XC % GENOTYPE PHENOTYPE_____ __________ ___________________ _____ __________ ___________________ XCXc 50% Normal females XCY Normal males 50%
X-LINKED RECESSIVE CROSS Normal male X Color Blind female XC Y Pattern depends on whichparent has the mutation! XCXc XcY XCXc XcY Xc Xc % GENOTYPE PHENOTYPE_____ __________ ___________________ _____ __________ ___________________ XCXc 50% Normal females XcY Color blind males 50%
X-LINKED RECESSIVE Hemophilia male X Normal carrier Female Xh Y XHXh XHY XhXh XhY XH Xh % PHENOTYPE ____ _________________ ____ _____________ ____ ___________________ _______________ 25% normal females (carrier) 25% normal males 25% hemophilia females 25% hemophilia males
X-LINKED RECESSIVE Normal male X Female (carrier) XD Y DuchenneMuscular Dystrophy XDXD XDY XDXd XdY XD Xd % PHENOTYPE ____ _________________ ____ _________________ ____ _________________ ____ _________________ 25% normal female (carrier) 50% 25% normal female 25% normal male ALL __________ normal ALL DMD’s are _________ females 25% DMD male male
X-LINKED DOMINANT XLH male X normal female XH Y X-linked Hypophosphatemia (XLH) (Vitamin D-resistant rickets) X-LINKED DOMINANT disorderBone deformities & short stature XHXh XhY XHXh XhY Xh Xh % PHENOTYPE ____ _________________ ____ _________________ 50% XLH female 50% normal male males ALL __________ normal ALL XLH’s are _________ female
X-LINKED DOMINANT Normal male X XLH female (mom didn’t have XLH) Xh Y X-linked Hypophosphatemia (XLH) (Vitamin D-resistant rickets) X-LINKED DOMINANT disorderBone deformities & short stature XHXh XHY XhXh XhY XH Xh % PHENOTYPE ____ _________________ ____ _________________ ____ _________________ ____ _________________ 25% XLH female 25% normal female 25% XLH male 25% normal male
TEST CROSSESA DOMINANT looking organism could have either of these genotypes: __________ OR __________ Can’t tell which by looking. A test cross is used to determine which it is.ALWAYS TESTCROSS WITH A ____________________________ organismOffspring provide clue about genotype of unknown parent. Tt TT HOMOZYGOUS RECESSIVE T T T t Tt Tt Tt Tt Tt tt Tt tt t t t t 100% of offspring will be TALL 50% probability offspring will be TALL 50% probability offspring will be SHORT
T T T t Tt tt Tt tt Tt Tt Tt Tt If ANY offspring show the recessive trait . . . unknown parent genotype was _____. If ALL offspring show the dominant trait . . . still don’t know. BOTH genotypes could produce offspring that look dominant! DO ANOTHER TEST CROSS FOR MORE DATA! Tt t t t t
Fire breathing (F) is dominant in dragons.NON-firebreathing (f) is recessive. You have a fire-breathing dragon. What are its possible genotypes? ______ OR _____ Show the results of test crossing BOTH of the possible parent genotypes. FF Ff F f F F Ff ff Ff ff Ff Ff Ff Ff f f f f
An actual test cross results in a litter with: 6 firebreathing dragons 2 NON-firebreathers What can you conclude about the unknown parent’s genotype? Since test cross produced offspring with recessive phenotype unknown parent genotype must be Ff FF parent can’t make NON-firebreathingoffspring.
Deafness in dogs is caused by a recessive allele.Deaf dogs have the genotype dd. You have a hearing dog. What are its possible genotypes? _________ __________ Show the results of test crossing BOTH OF THE POSSIBLE PARENT GENOTYPES: Dd DD D D D d d Dd dd Dd dd d Dd Dd Dd Dd d d