D.N.AObjective: SWBAT define key terms used in genetics IOT

explain the process of biological inheritance

QUESTION: How do we know which genes we will inherit from our parents, and which

genes will show up in our bodies?

-For example, if your mother has blue eyes, and your father has brown eyes, how do you know what color

eyes you will have?

ANNOUNCEMENTS!

• HOMEWORK: Genetics Worksheet

• RACE to the HSA for March begins next week– Maintain 10 points a class– The winning team will get a reward!

Think for a second about the most crazy thing you

have ever seen…

could be possible…

Imagine in the future when

something like THIS …

The future is now…

How did the

scientists do it?

Intro. To Genetics

Rock, Paper, Scissors – Dominant vs. Recessive Traits!

• When an offspring is formed, its traits are determined by a combo of genes from each parent

• Genes are either dominant or recessive

• 1. Find a partner and play, “Rock, Paper, Scissors”• 2. Play 5 times and record which partner won with

which type of hand

GENETICSthe study of how traits

are passed from one generation to the next

Gregor Mendel (Father of Genetics)

A scientist who studied geneticsHe did his

studies using normal garden peas

What He Studied

• Mendel looked at traits of the pea plants – A trait is a characteristic – Examples: seed color, height of the plant…

What are some traits of this person?

What Mendel Wanted to Know…

• He wanted to see if you crossed 2 plants with different traits, what would the offspring look like

From his experiments he concluded

• Inheritance is determined by factors that are passed from one generation to the next

GENE:the factors that control traits

(found in the DNA)example: color of a

flower

ALLELES• Each gene comes in different forms called alleles

• Each parent gives one allele to the offspring

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

CFUs• 1. Genes are found where?

• 2. What are the different forms of a gene called?

• 3. What would be an example of a gene and its alleles?

• 4. Where do the alleles come from?

DNADNA

ALLELESALLELES

Gene- Height, Alleles- tall and shortGene- Height, Alleles- tall and short

One from each parent!One from each parent!

Which one do you look like?

• Genes can either be dominant or recessive

Dominant Genes

• If a dominant gene is present, the trait is ALWAYS expressed

• Dominant alleles are written with a capital letter

• Example: Tall pea plant = dominant =T

Recessive Genes

• Recessive genes are ONLY expressed if there are 2 copies of the recessive allele

present – Recessive alleles are written with a lower

case letter

– Example: Short pea plant = recessive = t

Example…

• The gene for brown hair is dominant so….an individual just needs one B for the trait to be expressed

– BB = brown hair

– Bb = brown hair

Examples…

• The gene for blond hair is recessive and represented by a lower case b.

– bb = blond hair

You can’t express everything!

• Vocabulary –Genotype: Genetic makeup–Examples: TT, Tt, tt

–Phenotype: Physical characteristics–Examples: Tall, short, blue, long

Heterozygous vs. Homozygous

• Vocabulary: – Heterozygous: copies of different genes

• Hetero - different

• Example: Tt– Homozygous: copies of the same genes

• Homo - same

• Example: TT or tt

Let’s Practice

1. Circle one: “PP” is considered (homozygous/heterozygous)

1. Circle one: “Pp is considered (homozygous/heterozygous)

1. Circle one: “pp” is considered (homozygous dominant/homozygous recessive)

Let’s Practice

For each genotype, determine the phenotype

1. Tall (T) plant is dominant over short (t) • TT ______________• Tt ______________• tt _______________

TALL

TALL

SHORT

Let’s Practice

For each phenotype, list the genotype

1. White flowers are dominant to purple flowers• White flowers _________• White flowers _________• Purple flowers _________

Wwww

WW

CLASSWORK

• You will have 25 minutes to complete the Genetics Practice

Packet!

• Afterwards….we will have an EXIT TICKET!

How can we determine what the offspring are going

to be?

PUNNETT SQUARES

chart showing the possible combination

of alleles in a cross

THE PARENTSGENOTYPES• MOM = Bb (heterozygous brown hair)• DAD = bb (homozygous blond hair)

PHENOTYPES• MOM = brown hair• DAD = blond hair

b b

b

B B b B b

b b b b

THE OFFSPRING

• Tt (heterozygous)• Tt (heterozygous)• tt (homozygous recessive)• tt (homozygous recessive)

GENOTYPES

THE OFFSPRING

• 2 Bb (brown hair)• 2 bb (blond hair)

PHENOTYPES

You Try!PARENTS (T represents tall)

GENOTYPES• 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

THE OFFSPRING

• TT (tall)• Tt (tall)• Tt (tall)• tt (short)

PHENOTYPES

D.N.A

• Compare a plant with a multicellular green alga, paying particular attention to plant adaptations to life on land.

Algae Plant-supported by water -rigid supporting elements-lack supporting tissues -discrete organs (roots, stems, leaves)

-lack of covering -covered by cuticle

Algae Plant-supported by water -rigid supporting elements-lack supporting tissues -discrete organs (roots, stems, leaves)

-lack of covering -covered by cuticle