PASS Objectives Content Standard 2.2 A sorting and recombination of genes in reproduction results in...

PASS Objectives Content Standard 2.2

A sorting and recombination of genes in reproduction resultsin a great variety of possible gene combinations from the offspring of any two parents.

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Gregor Mendel - 8 min

Mendel studied 7 characteristics

A segment of DNA controlling a trait

Any of severalalternative formsof a gene

A gene that masksthe effects of another

A gene whose effectis masked by the dominant gene

A trait for which thegenes of the pairare identical

A trait for which thegenes of the pairare different

The genetic makeupof an organism

The external appearance of an organism

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An offspring from parentswith different traits.

The traits of the offspringare a combination of the

traits of the parents.





DIFFERENT

SAME



DIFFERENT

SAME

genes are different -what kind of trait?



DIFFERENT

SAME



DIFFERENT

SAME

genes are alike -what kind of trait?



DIFFERENT

SAME

The 64 words of the language of genetics

Which color is dominant - Red or White?

pink is a BLENDof red & white

Probability - 7 min

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Humans reproduce in

relatively small numbers.

Most plantsand animalsreproduce in LARGE numbers.

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If you flip a coinonly 4 times - you may getfour heads.

heads - 100%tails - 0%

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If you flip a coin400 times - you WILL getvery close to:

heads - 50%tails - 50%

A Punnett Squareis a tool usedto predict thepossible offspringof a genetic cross.

Use a capital case first letter of the dominant trait torepresent the dominant gene

Use a small case of theSAME letter to represent the recessive gene

Heterozygous Red Parent

The possible genesfrom one parentgo here.

The possible genes from theother parent go here.

Drawthe

squares.

Fill inthe

letters.

These arethe genes

(genotypes)

possiblein the

offspring.

1 out of 4are RR

2 out of 4are Rr

1 out of 4are rr

Gametes

GameteCombinations

1/4 are RR

1/2 are Rr

1/4 are rr

3/4 are Red

1/4 are white

3/4 are Red

1/4 are white

Remember, it only takes ONE dominant gene for that trait to show...

3/4 are Red

1/4 are white

but BOTH genes must be recessive for thattrait to show.

In certain trees, smooth barkis dominant over wrinkled.

Cross two trees that are heterozygous for smooth bark.

If there are 100 offspring produced, how many will have wrinkled bark?

What are the genotypes of the parents?





S s X S s

How do we begin to draw the Punnettsquare?

S s

S

s

S s

S

s

SS Ss

Ss ss

S s

S

s

SS Ss

Ss ss

This is the Punnett squarefor the cross.

S s

S

s

SS Ss

Ss ss

What do we need to know?

S s

S

s

SS Ss

Ss ss

Which square is wrinkled bark?

S s

S

s

SS Ss

Ss ss1/4

wrinkled

How do we use this to answer the question?

S s

S

s

SS Ss

Ss ss1/4

wrinkled

25 out of 100 will havewrinkled bark.

In flying purple people eaters, one-horn is dominant and no-horn is recessive.

Draw a Punnett square showing the cross between two heterozygous one-horn flying purple people eaters.

Use H for one-horn and h for no-horn.

What are the genotypesof the parents?


H h X H hNow draw the Punnett square.

H h

H

h

HH Hh

Hh hh

H = one-horn h = no-horn

In flying purple people eaters, one-eye is dominant and no-eye is recessive.

Draw a Punnett square showing the cross between two heterozygousone-eye flying purple people eaters.

Use E for one-eye and e for no-eye.


E e X E eNow draw the Punnett square.

E e

E

e

EE Ee

Ee ee

E = one-eye e = no-eye

The probability of independent events occurring together is the PRODUCT of the probabilities of the individual events.

If two heterozygous one-eye, one-horn flying purple people eaters are crossed, what fraction of the offspring will be no-horn, no-eye flying purple people eaters?

If two heterozygous one-eye, one-horn flying purple people eaters are crossed, what fraction of the offspring will be no-horn, no-eye flying purple people eaters?

Use the 2 squares you have and the product rule to answer the question.

How manyare no-horn?

1/4 will be no-horn

1/4 will be no-horn

How many areno-eye?

1/4 will be no-horn

1/4 will be no-eye

1/4 will be no-horn

1/4 will be no-eye

Using the product rule - 1/4 X 1/4 = 1/16

1 out of 16 will be no-horn, no-eyeflying purple people eaters.

r w

r

w

rr rw

rw ww

What's wrong with this Punnett square?

r w

r

w

rr rw

rw ww

A Punnett square with no capitalletters show incomplete dominance.

Dominance is incomplete in tulips.

What color are the offspringwhen a homozygous red tulipis crossed with a homozygous white tulip?

Use the small case firstletter of each trait torepresent the genes.

r = redw = white

r r

rr X ww w

w

rw rw

rw rw

All the offspring are PINK.

What color are the offspring when two pink tulips are crossed?

r w

rw X rw r

w

rr rw

rw ww

1/4 red1/2 pink1/4 white

Genes for sex-linkedGenes for sex-linked

traits are located on traits are located on

the the X chromosomeX chromosome..

Colorblindness is aColorblindness is a

sex-linked trait -sex-linked trait -

located on the Xlocated on the X

chromosome.chromosome.

The gene for normalThe gene for normal

color sight is Xcolor sight is XCC..

The recessive gene for The recessive gene for

colorblindness is Xcolorblindness is Xcc..

What would be theWhat would be the

genotype for a genotype for a

colorblind female?colorblind female?



colorblind female?colorblind female?XXccXXcc



colorblind male?colorblind male?



colorblind male?colorblind male?XXccYY

This female would haveThis female would have

normal vision but normal vision but

would be a "carrier"would be a "carrier"

of the colorblind gene.of the colorblind gene.

XXCCXXcc

A S e x - L i n k e d T r a i t

Traits are influenced Traits are influenced

by sex hormones...by sex hormones...

but located on abut located on a

chromosome otherchromosome other

than a sex than a sex

chromosome.chromosome.



"Male-pattern baldness"Male-pattern baldnessis a sex-influenced trait.is a sex-influenced trait.



Hair loss in women is usually aHair loss in women is usually ageneral thinning all over the scalp.general thinning all over the scalp.

Traits controlled by

the additive effect of

multiple alleles.

It IS even possible for

more than one pair of

genes to have an

effect on the same trait.

Bell Curve

Average Value

Extreme

Value

Extreme

Value

Average Height

Short Tall

Shorter LongerSame

short or long index finger

Fold your hands together by interlocking your fingers.

Which thumb is on top?

Dominant - L_ Recessive - ll

Dominant - S_ Recessive - ss

Dominant - T_ Recessive - tt

Dominant - W_ Recessive - ww

unattached attachedDominant - E Recessive - ee

Dominant - D_ Recessive - dd

Dominant - F_ Recessive - ff

Female

Marriage Line

Offspring Line

Sibling Line

Oldest child

Oldest child

Youngest child

Shows the trait in question

Does not show the trait in question

Carries the trait butdoes not show it

No Widow's Peak

No Tongue-rolling

Attached Ear Lobes

Hitch-hiker'sThumb

Pick a RECESSIVE trait that YOU have

Right-thumbed

Write your name and the trait you are using at the top of

the paper.

Color in YOUR square or circle on the chart

Take your pedigree chart home tonight and check the people on the

chart that you can actually see.

Put a question mark in the squares or circles for those you do not see.

Bring your completed pedigree chart to class tomorrow.

Does A food taste the same to everyone?





WHY?





1. Taste plain paper the control

2. Taste PTC paper describe the taste

Phenylthiocarbamide (PTC)is a chemical produced by plants like cabbage, broccoli,Brussel sprouts, turnips,and kale.

70% of the U.S. populationdetects at least some bitterness when they taste PTC.

TT - very bitter

Tt - slightly bitter

tt - non-taster

Tasters show a greatersensitivity to a widerange of tastes...



including bitter, sweet,and oral irritants such as capsaicin in chili pepper

Non-taster and tasterstatus has clearimplications for one'sperception of taste of a wide range of foods.

Genetic Engineering

Genetic Engineering

the application of molecular genetics for a practical purpose.

Recombinant DNA is a combination of DNA from two or more sources.

One of the best applicationsof recombinant DNA todayis the production of insulin.

The human gene forinsulin productionis isolated from a human cell.

The human gene isthen inserted intobacteria DNA.

The recombinant DNAis inserted into abacterial cell.

When the bacteria cellreproduces, all of itsoffspring will havethe human gene.

Eventually, Trillions of bacteria cells are producing human insulin.

Vats of bacteria producing insulin

You want another one just like HIM?!!

The nucleus (DNA) is removed froman egg cell.

The nucleus (DNA) from abody cell isinserted intothe empty egg cell.

A structuresimilar to a fertilized egg cell isproduced.

The cell beginsto divide and produce an embryo.

Eventually producinga complete organism.

Doctor,I believe your

cloning protocols are wrong!

Eugenics, altering gene pools to improve the traits in human populations, was a thriving science inthe 1930's.

Why isn't eugenicsaround today?

Who is the father of modern genetics?


Gregor Mendel

How many pea traits did he follow?

How many pea traits did he follow?

7

What theory did WalterSutton propose in 1903that supported Mendel'sideas about traits?

chromosome theory

What theory did WalterSutton propose in 1903that supported Mendel'sideas about traits?

A ___ is a segment ofDNA controlling a trait.

gene

A ___ is a segment ofDNA controlling a trait.

A gene that masks theeffect of another is ___

dominant gene

A gene that masks theeffect of another is ___

A gene whose effect ismasked is ___

recessive gene

A gene whose effect ismasked is ___

A trait for which thegenes of the pair areidentical

homozygous trait

A trait for which thegenes of the pair areidentical

A trait for which thegenes of the pair aredifferent

heterozygous trait

A trait for which thegenes of the pair aredifferent

genotype


The external appearanceof an organism

phenotype

The external appearanceof an organism

An offspring fromparents with different traits

hybrid

An offspring fromparents with different traits

Genes are combination of___ (a number) DNA basescalled codons.

3

Genes are combination of___ (a number) DNA basescalled codons.

The passing of traits fromone generation to the next

heredity

The passing of traits fromone generation to the next

A Punnett square is basedon mathematical ___

probability

A Punnett square is basedon mathematical ___

Capital letters on aPunnett square represent

dominant genes

Capital letters on aPunnett square represent

A Punnett square withno capital letters tells you

neither gene is dominant

A Punnett square withno capital letters tells you

What is the name of across involving onlyone trait?

monohybrid cross

What is the name of across involving onlyone trait?

What letters go here?

X

What letters go here?

rr

Genes for sex-linked traitsare located on the ___chromosome.

X

Genes for sex-linked traitsare located on the ___chromosome.

Sex-influenced traits aredifferent in each sexbecause of ___

sex hormones

Sex-influenced traits aredifferent in each sexbecause of ___

Traits controlled by theadditive effects ofmultiple alleles are called ___ traits.

polygenic

Traits controlled by theadditive effects ofmultiple alleles are called ___ traits.

A chart tracing the historyof a trait through severalgenerations.

pedigree chart

A chart tracing the historyof a trait through severalgenerations.

Males are represented by

females are represented by

Why is this square colored in?

He has the trait in question.

Why is this circle half-colored in?

She is a carrier.

Which is the oldest child?

The first one on the leftis always oldest.

The application ofmolecular genetics fora practical purpose.

genetic engineering

The application ofmolecular genetics fora practical purpose.

A combination of DNAfrom two or more sources.

recombinant DNA

A combination of DNAfrom two or more sources.


Gregor Mendel

PASS Objectives Content Standard 2.2 A sorting and recombination of genes in reproduction results in...

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