Exploring Mendelian Genetics

Exploring Mendelian Genetics

http://www.eslkidstuff.com/images/tallshort.gif

http://sps.k12.ar.us/massengale/genetics%20tutorial.htm

Must know terms

Trait—specific characteristic varies from one individual to another example height

Hybrid—offspring of crosses between parents with different traits

Dominant—expressed trait

Recessive—non expressed trait: present only in the absence of the dominant

Must know terms

• Homozygous—individuals with two identical alleles for a particular trait –true breeding

• Heterozygous—individuals with two different alleles for a particular trait—hybrid

• Phenotype—Physical characteristics• Genotype—Genetic makeup

Must know terms

• Allele—Different forms of a gene• P generation—Parental generation• F1 generation—first generation after P

• F2 generation—second generation after P

• Probability—is the likelihood that a particular event will occur

GENES are more complicated than Mendel thought

____________________________ the ________________________.

= ________________________

Genes ________ the ______ for development, but how plan unfolds also _______ on ______________conditions.

“Nature vs Nurture”

ENVIRONMENT influences

expression of genes

provide plan

depends environmental

GENES are more complicated than Mendel thought

Some traits have ____________ allele __________

= ____________________

EX: blood type

Allele choices ___ ___ ___

MULTIPLE ALLELE TRAIT

A B O

MORE than 2 choices

GENES are more complicated than MENDEL thought

Some traits are determined by ____________________________= __________________

EX: human height. intelligence,

skin & eye color

http://www.bcps.org/offices/lis/models/life/images/grow.JPG

POLYGENIC TRAITMORE THAN ONE GENE


Traits determined by ____________ _________ have _____“___________” phenotypes

http://www.newtonswindow.com/problem-solving.htm

There aren’t just SMART people and DUMB people…. there is a ________________of intelligences in-between

MORE thanONE gene many

in-between

whole range


KINDS OF DOMINANCE

____________________

____________________

____________________

COMPLETE DOMINANCEINCOMPLETE DOMINANCECO-DOMINANCE

COMPLETE DOMINANCE

__________ allele _______ the ___________ one

PATTERN ?____________ allele ________

in a _____ratio in the ____ generation

Dominant masks recessive

Recessivereturns

3:1F2

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

INCOMPLETE DOMINANCE

__________ expected

_____ ratio in

F2 generation

_____________ organisms with one dominant and one recessive allele show a _________ in-between traitBLENDED

DON’T SEE

3:1

Heterozygous

Image modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

CO-DOMINANCE_______ traits are expressed at ___________

(_____________________) in heterozygote

A ________HORSE has ______________ hair and __________ hair side by side

BOTH SAME TIME

ROAN

BOTH RED WHITE

NO BLENDING

CO-DOMINANCEBoth 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= _________________________

The pattern of sugars that is attached is determined by genes

Allele choices are:

_____ ____ ____ A B O

MULTIPLE ALLELE TRAIT

BLOOD TYPES & ALLELES

GENOTYPEPHENOTYPE

(BLOOD TYPE)AA

AO

BB

BO

OO

AB

A

A

B

B

O

AB

BLOOD TYPES

Body images modified from: http://www.new-fitness.com/images/body_shapes.jpg

YOU DON’T HAVE ANYTHING I DON’T HAVE!

____ can donate to EVERY BLOOD TYPE = _____________________

Nothing on surface to recognize as “NOT SELF”

UNIVERSAL DONOR

O

BLOOD TYPES

Body image modified from: http://www.new-fitness.com/images/body_shapes.jpg

______ can RECEIVE FROM EVERY BLOOD TYPE = ________________________UNIVERSAL RECIPIENT

AB

BLOOD TYPE FREQUENCY IN USA

http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/BldTyping.html

A 40%B 10%

AB 4%O 46%

MENDEL’S PEA EXPERIMENTS

Mendel started his experiments with peas that were _________________

= if allowed to _________________ they would produce ____________________ to themselves.

http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif

true breeding

self pollinate

offspring identical

A _____________________ is called a ____________

Mendel ______________ in peas.

specific characteristic

trait

Pearson Education Inc,; Publishing as Pearson Prentice Hall

studied 7 traits

MENDEL’S EXPERIMENTS

____ generation (_________)

____ generation

(______= offspring)

___ generation

P1

F1

F2

parental

filial

P Generation F1 Generation F2 Generation

Tall Short Tall TallTall Tall Tall Short

Section 11-1

Principles of Dominance

When Mendel ______________ PLANTS with 2 ______________ traits:(EX: Tall crossed with short)

He always found same pattern: 1. ONLY ______ trait ____________

in the ____ generation BUT . . .

2. ___________ trait ____________ in the ____ generation

in a _________ ratio

ONE showedF1

F2

3:1

crossed PURE contrasting

Missing returned

PATTERNS ARE THE KEY

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

Mendel decided that there must be a __________________ that ________each trait and that

__________ must be able to _______ the other.

pair of FACTORS

one factor

control

HIDE

DIHYBRID CROSSES(2 traits)

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

Mendel also asked the question?

Does the gene that determines if a seedis round or wrinkled have anything todo with the gene for seed shape?

Must a seed that is yellow also be round?

MAKING A CROSS with ___________________=____________________

A Punnett square for a DIHYBRID CROSS looks like this:

DIHYBRID CROSSTWO gene traits

Go to Section:

Section 11-3

Figure 11-10 Independent Assortment in Peas

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

1. ___________ what _________________ are2. ________correct__________ square __________3. ______ possible_______________________4. ______ boxes with _____________________5. Determine ____________of_____________& ____________

LET’S MAKE A DIHYBRID CROSSHOMOZYGOUS

YELLOW ROUND

rryy

HOMOZYGOUSGREEN WRINKLED

Figure out parent allelesChoose Punnett sizePut in parent gametesFill in offspring combinations probabilities phenotypes

genotypes

RRYY

R R Y Y

HOMOZYGOUS ROUND YELLOW

PRACTICE MAKING GAMETESWHAT ARE THE POSSIBLE GAMETES THIS PARENT CAN MAKE?

Each gamete shouldget one of each kindof gene

___________ ____________ _____________ _____________R Y R Y R Y R Y

r r y y

HOMOZYGOUS WRINKLED GREEN



___________ ____________ _____________ _____________r y r y r y r y

R r Y y

HETEROZYGOUSROUND YELLOW



___________ ____________ _____________ _____________R Y r y r Y R y

ry ry ry ry

RY

RY

RY

RY

100% of offspring = _______ genotype _______________________ phenotype

RrYyROUND YELLOW

RrYy RrYy RrYy RrYy

RrYy RrYy RrYy RrYy

RrYy RrYy RrYy RrYy

RrYy RrYy RrYy RrYy

R r Y y R r Y y



MAKE ANOTHER CROSS

X

POSSIBLE PARENT GAMETES?

RY ry RyrY

RY Ry rY ry

RY

Ry

rY

ry

Sign of a ______________________ cross is a_____________ ratio in offspring.9:3:3:1

____ Round & Yellow

____ Round & green

____ Wrinkled & yellow

____ wrinkled & green

9

3

3

1

RRYY RRYy RrYY RrYy

RRYy RRyy RrYy Rryy

RrYY RrYy rrYY rrYy

RrYy Rryy rrYy rryy

heterozygous dihybrid

__________ratio is a clue that it’s a ____________________________cross

____ ____________ TRAIT 1 ; ____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2

____ ____________ TRAIT 1; _____________ TRAIT 2

____ ____________ TRAIT 1; _____________ TRAIT 2

9

3

3

1

9:3:3:1

HETEROZYGOUS TWO gene

dominant dominant

dominant recessive

recessive dominant

recessive recessive

PRACTICE MAKING GAMETESfor DIHYBRID CROSSES

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

pure round & pure tall = __________

____ ____ _____ ______

What gametes can it produce?

What are the possible gametes?

R R T T

R T R T

R T R T

Heterozygous Tall = __________

& pure round

____ ____ _____ ______



T t R R

T R T R

t R t R

Hybrid tall = __________

& pure wrinkled

____ ____ _____ ______



T t r r

T r T r

t r t r

Heterozygous tall = __________

& hybrid round

____ ____ _____ ______



T t R r

T R T r

t r t R

Exploring Mendelian Genetics

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