d.n.a objective: swbat define key terms used in genetics iot explain the process of biological...
TRANSCRIPT
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