Transcript Genotypic ratio

• 91. Cell Reproduction Notebook Check (stamped)
• 92. Karyotype Lab (graded)
• 93. Intro to Genetics Reading Guide (stamped)
• 94. Genetics Notes
• 95. Punnett Squares
• 96. More Punnett Square Practice
• 97. Exceptions to Mendel’s Rules
• 98. Oompah Loompa’s (stamped?)
• 99. Progress Report #6 (stamped)
• 100. POP QUIZ!
• 101. Pedigrees (a & b)
• 102. Ugly Baby Lab
• 103. Genetic Disorders (stamped)
• 104. Genetic Technology (a. notes & b. activity sheet)
• 105. Progress Report #7 (stamped)
• 106. Biotechnology Review
• 107. Genetics Practice
• 108. Genetics Notebook Check – starts on 3/31/11
• 3/31 & 4/4 Genetics Unit TEST and
Notebook Checks!
• 4/1 Teacher Workday!
• Castle Learning Practice/Extra Credit
closes on 3/30 at midnight!
a medical procedure used to
diagnose chromosomal disorders in a
developing fetus. A small amount of
amniotic fluid, which contains fetal
tissues, is extracted from the
amniotic sac surrounding a
developing fetus, and the DNA is
examined.
• Gregor Mendel = father of heredity
–Mid 1800s
–Studied garden pea plants (because they
could produce purebred individuals)
–Studied how traits were passed from one
generation to the next
–Mendel came up with several important
concepts
1. Parents pass on genes
2. For each trait, an organism has 2 genes (1
allele from Mom and 1 from Dad)
3. Alleles can be dominant and recessive
• Tall plants could equal TT or Tt, short = tt
• Genotype = genetic make-up for trait (TT)
• Phenotype = physical look of trait (tall)
• If organisms contain two identical
alleles for a trait, it shows that trait.
Curly hair = HH
Straight hair = hh
• If organisms contain two different
alleles for a trait, it shows the
dominant trait.
Curly hair = Hh
Used to
predict the
possible
combinations
of dominant
and recessive
alleles in the
offspring.
Genotypic ratio = 1 RR : 2 Rr : 1 rr
Phenotypic ratio = 3 pink : 1 yellow
• Dad = XY, some
sperm have X, some
have Y
• Mom = XX, all eggs
have X because
that’s all Mom has
to donate
• Who determines
gender of baby –
Mom or Dad?
The genes for traits found on different
chromosomes separate independently when
gametes are made.
A deliberate genetic
cross with a
homozygous
recessive individual
that can be used to
determine whether
an organism is
homozygous or
heterozygous
dominant for a trait.
Phenotype is a mix of genetics
and environment
Mostly
Environment
Language
Religion
Mix
Height
Weight
Intelligence
Mostly
Genetic
Blood type
Eye color
#96 More Punnett Square Practice
(make Punnett Squares & describe offspring using genotypic and phenotypic ratios)
1.
2.
3.
4.
5.
6.
Green pea plant (GG) X Green pea plant (Gg)
Tall plant (TT) X short plant (tt)
Two tall plants (Tt)
Two white flowers (white = recessive)
Homozygous red flower X white flower
Homozygous dominant brown mouse X
heterozygous brown mouse (tan = recessive)
7. Heterozygous white rabbit X black rabbit.
8. Two heterozygous white rabbits. (black = rec)
9. How would you figure out if a purple plant
(dominant) is heterozygous vs. homozygous?
GENOTYPIC RATIO
PHENOTYPIC RATIO
Sometimes genetics isn’t
always as simple as Mendel’s
Law of Dominance
• Heterozygote is a BLEND of the 2
homozygotes
• RR = red flowers
• rr = white flowers
• Rr = PINK flowers
• Cross two pink flowers.
• Genotypic ratio 1:2:1
• Phenotypic ratio 1 red: 2 pink: 1 white
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Heterozygote show BOTH traits
BB = black cows
WW = white cows
BW = black & white
BB X WW
All BW offspring
Genotypic ratio = 0:4:0
Phenotypic ratio = 0:4:0
• Traits that have more than two alleles.
• Blood types –
3 alleles
A and B are co-dominant
O is recessive to A and B
4 phenotypes
1)Type A
blood contains “A” proteins
genotype: AA or AO
 2) Type B
blood contains “B” proteins
(genotype: BB or BO)
3)Type AB
blood contains both proteins
genotype: AB
4) Type O
neither protein present in blood
Genotype: OO
• AB is an example of ________________.
• Several genes are inherited from
each parent for 1 trait.
• Many possible phenotypes.
• Examples: skin color, eye color,
height, weight
ABC, ABc, AbC, aBC = dark
abc, abC, Abc, aBc = light
ABC
ABC
ABc
AbC
Abc
aBC
aBc
abC
abc
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5
5
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3
ABc AbC Abc aBC aBc abC abc
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0
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Located on X chromosome
Females are only carriers
Mostly males are affected
Colorblindness, hemophilia, baldness
XBXB = normal female
XBXb = carrier female
XbXb = colorblind female
XBY = normal male
XbY = colorblind male
Cross a carrier female with a normal male.
Explain the possible offspring.
Human Genome - identifying the 30,000+
genes in human DNA and the order of the
bases A, C, T, and G.
• Discovering new ways to diagnose, treat &
prevent genetic disorders
• Trying to identify the location of all genes on
chromosomes
• To sequence DNA, scientists use restriction
enzymes and gel electrophoresis
Applications of Biotechnology
1. DNA fingerprints
–Analyzing the sequences of DNA to
determine similarities or differences
between different samples of DNA
2. Restriction enzymes
–Cut fragments of DNA so that scientists
can place them on gel electrophoresis
–Steps of gel electrophoresis:
1. Blood/cell sample is isolated
2. Extract DNA
3. Cut DNA using restriction enzymes
4. Place fragments on gel
5. Fragments separated by electrical
current
6. DNA bands can be matched/compared
3. Transgenic organisms
–Have DNA from another species inserted
into their own DNA
–Restriction enzymes cut plasmid DNA
(circular, not chromosomal) and foreign
DNA
–“Stick” them together – makes recombinant
DNA
4. Amniocentesis (see karyotype lab)
5. Cloning - making genetically identical
organisms
–4 steps: (see page 333)
WHAT ARE THESE THINGS??
Gel electrophoresis video
WHAT PROCESS?
# THE STEPS!
1. Refers to an individual’s observable traits.
2. Which of the following describes a phenotype?
a. Gg
b. homozygous
c. dimples
d. heterozygous
3. What term describes an organism in which two alleles
for a trait are different?
4. Crossing a purebred, purple-flowered plant with a
purebred, white-flowered plant can be symbolized by
which of the following genotype crosses?
a. Ff X ff b. FF X ff c. Ff X Ff d. FF X FF
5. Two pea plants are crossed, TT X tt. Make a Punnett
Square. Write the genotypic ratio.
6. AB blood is a result of what type of inheritance?
7. Know how to determine genotypic & phenotypic
ratios…
8. Know how to analyze pedigrees…
9. White short-horned cattle and Black Angus cattle have been
crossed to produce offspring with superior beef and rapid
growth qualities. The process of choosing organisms with
the most desirable traits for mating is…
10. Non-disjunction involving the X chromosome occurs during
oogenesis and produces XX eggs and 0 eggs. If normal Y
sperm fertilize the eggs, which genotypes are possible?
a. XX &XY b. XXY &YOc. XYY & X0 d. XYY & X0
11. Huntington’s disease is what type of disease?
12. What is the job of a restriction enzyme?
13. A male with IAIB blood has a wife with O blood. What are
the possible blood types of any children they may have?
14. Scientists have cloned sheep, but not yet a human. Why
not, do you think?
15. What is a transgenic organism?
I, II, III, IV
a) Individual showing the
trait being tracked
b) Male
c) Generation #
d) Offspring with birth
order left to right
e) Female
f) Marriage/mating
g) Sex undetermined
Words To Know
10. Karyotype
1. Pleiotropy
11. Cloning
2. Codominance
12. Test cross
3. Incomplete
dominance
13. Sex-linked vs.
4. Polygenic Inheritance autosomal
5. Homozygous vs.
14. mRNA vs. tRNA
heterozygous
15. Synapsis
6. Plasmid
16.
Crossing
Over
7. Alleles
17. Non-disjunction
8. Replication,
Transcription &
18. Diploid vs. haploid
Translation
19. DNA fingerprint
9. Recombinant DNA
20. Trisomy