catalyst catalyst: complete a dihybrid cross for a heterozygous tall person and a homozygous short...

CATALYSTCATALYST

Catalyst: Complete a dihybrid Catalyst: Complete a dihybrid cross for a Heterozygous Tall cross for a Heterozygous Tall person and a Homozygous Short person and a Homozygous Short Person. T = Tall, t = ShortPerson. T = Tall, t = Short

Mr. Gibney will start this on board Mr. Gibney will start this on board promptly when bell ringspromptly when bell rings

CURRENT EVENT BY FRIDAY!!!!CURRENT EVENT BY FRIDAY!!!!

HOMEWORK REVIEWCURRENT EVENTS (I will give

you till Wednesday)

-HELP US See Science in everyday life

“Very nice résumé. Leave a sample of your DNA with my

secretary.”

Gibney Bucks Review!!!

How do mitosis and meiosis differ? How are people either male or female? What is DNA? What is replication? What is transcription? What is translation? When is Reading day this week?

STUDY

ROCK THIS CLASS

YOU CAN BRING YOUR GRADE UP IF YOU TRY!

Think for a second about the most crazy thing you have ever

seen…

when something like THIS could be

possible…

Imagine in the future…

The future is now…

WELCOME TO

GENETICS!!!

Follow Along

• In Book Ch 10

• Fill in guided notes as we go along and if you miss something… check out the book!

•WHY THIS IS IMPORTANT!!!!!!

GENETICSthe study of how

traits are passed from one generation to the

next

TRAITa characteristic

Examples:Plant size, seed color, pod shape

TRAITS YOU TRAITS YOU MIGHT MIGHT HAVE…HAVE…

Can you curl Can you curl your tongue?your tongue?

Can you wiggle Can you wiggle your ears?your ears?

Can you raise Can you raise just one just one eyebrow?eyebrow?

USA: 82% YesUSA: 82% Yes

USA: 27% YesUSA: 27% Yes

USA: 64% YesUSA: 64% Yes

GENESGENESEach feature of the pea plants is controlled by a Each feature of the pea plants is controlled by a

genegene. It may have a gene that controls its color, . It may have a gene that controls its color, another for size and another for shape.another for size and another for shape.

GENEthe factors that control traits

(found in the DNA)

Above you see chromosomes. The circled area is a gene on chromosome #22. The

absence of this gene causes velo-cardio-facial syndrome (VCFS) which may

cause ADD and mental illness

ALLELESALLELESEach gene comes in different forms called Each gene comes in different forms called allelesalleles, ,

so the gene that controls flower color may come so the gene that controls flower color may come in two alleles: purple and white.in two alleles: purple and white.

ALLELESdifferent forms

of a gene

PURPLE MAN EATER PLANT PURPLE MAN EATER PLANT EXAMPLEEXAMPLE

Traits: 6ft tall, purple, eats peopleTraits: 6ft tall, purple, eats people Genes that control these traits are on Genes that control these traits are on

Chromosome 17Chromosome 17 Each of the three genes has different Each of the three genes has different

alleles: Can be 6ft tall or 3 ft tall, purple or alleles: Can be 6ft tall or 3 ft tall, purple or orange, eat people or vegetarianorange, eat people or vegetarian

GREGOR MENDEL The “father” of genetics Lived from 1822-1884 Austrian Monk Published his work in

1866, but no one took him seriously until 1900.

Studied Pea Plants!

MENDEL’S EXPERIMENTS

Mendel experimented with 7 different characteristics

Mendel Got Lucky for 2 Big Reasons1. First, he had a lot of time…he

was a monk. This let him do LOTS of experiments with the peas!

2. Each trait had 2 options. This was key because he could tell if it was one way or the other.

VOCABULARY

• "Think! How the hell are you gonna think and hit at the same time?"

HOMOZYGOUS organism with two identical alleles for

the same trait(TT or tt)

HETEROZYGOUS organism with two different alleles for

the same trait(Tt)

DOMINANTallele that is expressed when in the presence of a recessive allele

(TT or Tt = tall)

RECESSIVEallele that is expressed

only when homozygous(tt = short)

PHENOTYPEphysical

characteristics(Tall, Brown)

GENOTYPEthe genetic makeup

(TT, TtHh)

GENE = Height

ALLELE = Tall, Short

Gene is represented by the letter “t”

Dominant = TRecessive = t

Remember you need 2 copies of every gene!!!

How can we determine what the offspring are going to be?

PUNNETT SQUARES

Reginald C. Punnett

• Inventor of the Punnett Square

PUNNETT SQUARES

chart showing the possible combination

of alleles in a cross

Punnett Squares show the

probability of getting a certain type of offspring

THE PARENTSGENOTYPES• DAD = Tt (heterozygous)• MOM = Tt (heterozygous)

PHENOTYPES• DAD = Tall• MOM = Tall

PUNNETT SQUARES

THE OFFSPRING

• TT (homozygous dominant)

• Tt (heterozygous)

• Tt (heterozygous)

• tt (homozygous recessive)

GENOTYPES

1TT:2Tt:1tt (1:2:1)

THE OFFSPRING

• TT (tall)

• Tt (tall)

• Tt (tall)

• tt (short)

PHENOTYPES

3 Tall :1 Short (3:1)

STUDENT DEMOS UP FRONT

• Do student demonstration with genotypes

• Do bag demonstration with beans tomorrow

Cross a homozygous dominant with a recessive

(for height where T is dominant and tall).

Find the genotype and the phenotype

Cross a heterozygote with a recessive (for height where T

is dominant and tall).

Find the genotype and the phenotype

Cross a heterozygote with another heterozygote (for

skin color where Black is B, b = white).

Find the genotype and the phenotype

Cross a heterozygote with another heterozygote (for

nose size where big nose is N and small nose is n).

Find the genotype and the phenotype

• When you flip a quarter, what are the odds that a coin turns up heads? What about when you flip two coins at the same time, what are the odds that both turns up heads?

• Coin Flip Lab

• Coin 1 Coin 2 HeadsTailsHeadsTails    % Heads% Tails% Heads% Tails    

A cross between an unknown and a

homozygous recessive

Test Cross

Example of a Test Cross

Unknown

When a combination of the dominant and recessive creates a new phenotype. RR = red,

rr = white, and Rr = pink

Codominance

Codominance

RR Rr rr

Codominance Cross

Codominance Cross

a trait that is found on either the X or Y

chromosome

Sex Linked Trait

Hemophilia is an example of a sex

linked trait.

a disease where your blood doesn’t clot.

Hemophilia

Hemophilia only occurs when all of the

X chromosomes have a copy of the recessive

gene.

XHXh:female carrier XhXh:female hemophiliac

XHY:normal male XhY:hemophiliac male

SICKLE CELL ANEMIA

Difference between normal cells & sickle cells

Sickle Cell

ss = sickle cells

(lethal)

Ss = carrier (SC trait)

SS = normal

Sickle Cells tend to get stuck easily in the circulatory system.

Why would African American’s be so

much more likely to have Sickle Cell?

Regular red blood cells infected by malaria

chart that shows the relationships within a family

PEDIGREE

Pedigree Basics• Males are squares, females are circles, and

unborn babies are triangles or octagons

• Shaded figures represent individuals with the trait, a carrier could be 1/2 shaded

• Generations are numbered with roman numerals (I, II, II, IV) from top to bottom

• People within generations are numbered (1,2,3) from left to right

PEDIGREE HELP!!!!

200 B.C.Humans “clone” trees by cuttings

1950Humans clone frogs

1980’s Humans clone mice!

1997HUMANS CLONE SHEEP!!!

1998 Humans clone 8 copies of a cow!!!

20??

moving genes from one chromosome of one

organism to the chromosome of another

GENETIC ENGINEERING

“Fat” Gene

making an exact copy of another cell

/ organism

CLONING

Dolly—the first cloned sheep

Ian Wilmut, the dude that

did it

Check out this short movie that talks about cloning…

A dividing cell

Read NYTimes Article "Despite Warnings, 3 Vow to Go Ahead on Human Cloning"

a. What did three proponents of human cloning announce on August 7, 2001?

b. Where did they make this announcement? c. Why did some scientists at the symposium object

to the proponents' announcement? d. Why did Dr. Alan Colman object to the research

by these proponents being done in secret? e. According to the article, what was the consensus

among the panel and most of those who testified before it?

Read NYTimes Article "Despite Warnings, 3 Vow to Go Ahead on Human Cloning" f. Who was "Dolly"?g. What animals have been successfully cloned? h. According to the article, what is involved in cloning a human? i. How did the three proponents say they would

address the possibility of genetic abnormalities? j. How did other experts at the symposium respond

to this statement? k. Why do the proponents need to conduct their

research secretly?

•http://www.biology.washington.edu/bsa/karyotypeS.html

•http://worms.zoology.wisc.edu/zooweb/Phelps/karyotype.html

•http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html

•http://www.pathology.washington.edu/galleries/Cytogallery/cytogallery.html

•http://www.biology.iupui.edu/biocourses/N100/2k2humancsomaldisorders.html

A technique used to determine the genetic traits of a baby before

it is born

AMNIOCENTESIS

Klinefelter Syndrome• Have male genitalia and internal ducts, but

underdeveloped testes

• Do not produce sperm

• Slight enlargement of the breasts

• 47,XXY

• 1 out of every 500 male births

Turner Syndrome• Has female external genitalia

• Underdeveloped ovaries

• Short (under 5 feed)

• Webbed Neck

• Broad, Shield-like chest

• 45,X

• 1 out of every 3000 female births

Cri-du-Chat Syndrome• Partial monosomy (part of 1 chromosome is lost)• Loss of about 1/3 of the short arm of chromosome

5• Anatomical malfomrations (gastrointestinal and

cardiac complications)• Mentally retarded• Abnormal development of the larynx which makes

the baby’s cry sound like a cat’s cry• 1 in 50,000 live births

Down Syndrome• BKA trisomy 21 (47, 21+); 3 copies of the 21st chromosome• Short• Small round heads• Protruding, furrowed tongues which cause mouth to remain partially

open• Retarded (IQ below 70)• Shortened life expectancy (<50)• Prone to reparatory disease and heart malformations• Have 15x higher chance of getting leukemia• Chance of having a baby with Down syndrome goes up as the mother

gets older

Guided Notes Mini-Clinical: 10ptsGuided Notes Mini-Clinical: 10pts I meant to start these backup again but got I meant to start these backup again but got

caught up in the excitement of getting a caught up in the excitement of getting a room.room.

On a clean sheet of paper answer the On a clean sheet of paper answer the following… you may use your notesfollowing… you may use your notes

1.1. How do the base pairs in DNA matchup?How do the base pairs in DNA matchup?

2.2. What is the difference between DNA and What is the difference between DNA and RNA?RNA?

3.3. How do transcription and translation differ?How do transcription and translation differ?

4.4. Name 2 scientists that we talked about who Name 2 scientists that we talked about who helped “discover” DNAhelped “discover” DNA

5.5. Draw the pathway from DNA to protein.Draw the pathway from DNA to protein.

TRADE N GRADETRADE N GRADE

How do the base pairs in DNA matchup?How do the base pairs in DNA matchup? A-T, G-CA-T, G-C

Pedigree Basics• Males are squares, females are circles, and

unborn babies are triangles or octagons

• Shaded figures represent individuals with the trait, a carrier could be 1/2 shaded

• Generations are numbered with roman numerals (I, II, II, IV) from top to bottom

• People within generations are numbered (1,2,3) from left to right