Transcript Genetic Traits Environment

TAKS Objective 2 – The
student will demonstrate an
understanding of living
systems and the
environment
TEKS 8.11 A
Identify that change in
environmental conditions
can affect the survival of
individuals and of species
TEKS 8.11 B
Distinguish between
inherited traits and other
characteristics that result
from interactions with the
environment
Lesson Objectives:
Describe environmental
conditions that can have
significant impact on the
survival of individuals and
species
Using a digital camera, the
Internet, or other resource,
create a picture portfolio that
demonstrates understanding
of the differences between
genetic and environmental
traits
Write a research paper
about a birth defect
Communicate scientific
experimentation by recording
hypotheses, illustrations of the
experimental setup, data
collection instruments and
conclusions for an experiment
True or False
Biodiversity is unrelated to
survival
False
Biodiversity is important to
survival. A loss of homozygosity
such as inbreeding, susceptibility
to disease, can lead to
threatened/endangered status
and extinction.
True or False
With intervention any
species can be saved from
extinction
False
It is not always possible to remove
threat or endangerment to a species.
Once a species drops past a critical
number of individuals, it will molst likely
go extinct regardless of what we do.
True or False
Enviromental dangers are
usually visible.
False
UV radiation, CFCs, microscopic
organisms/viruses, and many forms
of pollution cannot be seen or
detected without special equipment.
Prior Knowledge
TEKS 7.10 – role of sexual reproduction in
diversity
TEKS 7.10B inherited traits are contained in the
DNA of cells and expressed by genes
TEKS 6.11 B&C – changes in DNA at the
phenotypic level can occur through mutation and
selective breeding
Background
Extinction is one of
the avenue, which
allows evolution to
occur
http://www.pbs.org/wgbh/evolution/library/03/2/image_pop/l_032_03.html
Changes in the
environment can have
significant impact on the
survival of individuals and
species
Changes in the
environment that
impact survival of
individuals and
species
•UV light
•Exposure to radiation such as
uranium mining, atomic bombs,
medical work with radiation
•Human activity involving
chemical released in soil, air, and
water
• Legal and illegal drugs
• Availability of resources such as food,
clean water, space, and shelter
• Climatic changes
• Human activity (habitat destruction and
pollution)
• Natural disasters (flood and volcano
• Parasites, bacteria, and viruses
• Distinguishing between characteristics that
result from interactions with the
environment (drug use HIV*) and inherited
traits (Down’s syndrom, Turner’s
syndrome)
ENGAGE
Initiate a discussion about what
might cause malformed frogs
Explore
Select students read aloud
the introduction to “Don’t
Leap to Conclusions:
Deformed Frogs in
Minnesota.”
 Explain
Think about at least one more hypotheses
about why these frogs were malformed?
Write an If…then hypothesis statement for
each possible cause of malformation.
Now let’s test each of the hypothesis
statements you have written. How
would you go about setting up an
experimental design for each of
these hypotheses?
Let’s see what a group
of researchers found
out
Which of the hypothesis does
the research support?
Elaborate
Students may learn more information about
the possible causes of malformed frogs
from the following websites:
http://www.pca.state.mn.us/hot/frog-bg.html
http://cgee.hamline.edu/frogs/science/malfor
m.html
Evaluate
• After completing the learning experience, “Don’t
Leap to Conclusions: The Case of the
Malformed Frogs, the student will be able to
describe in their journal at least seven
environmental conditions that can have
significant impact on the survival of individuals
and species.
• Teacher will monitor student progress during
the activity and provide assistance as needed.
Peer tutoring arrangements are used for ESL
students.
Killer Rays
 Engage
Visit this website:
http://www.epa.gov/sunwise/uvindex.html
UV Index
0-2 minimal
3-4 low
5-6 moderate
7-9 high
10+ very high
Explore
• Place UV beads in a plastic Ziploc® bag. Rub one
side of the baggie with a very thin layer of sunscreen
and let dry. Expose to direct sunlight and see if the
beads turn colors. Try different types of sunscreen.
• Place some beads under a sunglass lens in an area
that is exposed to direct sunlight. If the beads remain
white, then your sunglasses are blocking harmful
ultraviolet rays. Test different pairs of sunglasses.
Explain
The UV beads contain a pigment that changes
color in the presence of ultraviolet radiation from
the sun
ozone layer reflects or absorbs 99% of damaging
UV rays from the sun
There are a number of activities and events
that cause ozone destruction:
• Hydrogen bomb testing
• CFCs (chlorofluorocarbons) in aerosols
and refrigerants
• Exhaust gases from supersonic aircraft
• Fertilizers and
• Volcanic eruptions.
Elaborate
MD Anderson Sun Safety
Place some beads under the different colors
and types of fabric in an area that is
exposed to direct sunlight. Which colors
and types of fabrics best protect the beads
from the UV rays.
Evaluate
During the learning activity, “Exploring the
Effect of UV Radiation, the student will
record hypotheses, illustrations of the
experimental setup, data collection
instruments and conclusions for each
experiment in the science journal. A
completion grade will be given.
TEKS 8.11C
Predict possible outcomes
of various genetic
combinations of inherited
characteristics
Lesson Objectives:
•Apply understanding of probability by making
predictions
•Complete monohybrid cross problems
•Apply knowledge of Punnett squares to realworld situations
•Communicate information about genetic
disorders by creating a brochure for publication.
Extended Background for You
• Exceptions to Mendels rules
Incomplete Dominance
• The phenotype of
the heterozygote is
intermediate
between those of
the two
homozygotes.
• Ex) Snap Dragon
Color
• Red, Pink, White
Co-dominance
• Phenotype of both
homozygotes are
produced in
heterozygotes
individuals.
• Both alleles are
expressed equally.
• Ex)Roan Cattle
White-feathered
birds are both
homozygotes for
both B and W
alleles
Multiple Alleles
• Ex )Blood type
• Blood type A and B are co-dominant,
while O is recessive.
• Forms possible blood types of A, B, AB,
and O.
Blood Also Shows
Codominance
Sex-Determination
• Chromosome pairs 1-22 are autosomes
• Chromosome pair 23 are sex
chromosomes
• They determine the sex of an individual
• XX = female
XY = male
Sex-Linked Inheritance
• Traits that are only found on the X
chromosome
• Colorblindness and Hemophilia are
examples of sex-linked traits.
• These genes are recessive and found only
on the X chromosome.
Polygenic Inheritance
• Inheritance pattern
of a trait that is
controlled by two or
more genes.
• Gene may be on
the same
chromosome or on
different
chromosomes.
• i.e., Skin color and
Height
True or False
Dominant traits are always
the most common trait
found in a population
False
Not always. Having six fingers is
a dominant trait for humans, but
most humans are recessive for
this trait and have only five
fingers.
True or False
Males have more dominant
traits than females
False
Males are NO more likely than females
to have dominant traits.
True or False
Dominant traits are good to
have.
False
Many genetic disorders are caused
by dominant traits
•Huntington’s Disease
•Marfan’s Syndrome
True or False
Some students think the
theoretical probability is
what happens in real life.
False
Students should remember that
everyone does not have four
children and even if they did, the
“experimental probability” can
vary greatly when the population
is small.
True or False
Each roll, spin, toss and/or
draw is dependent on the
ones that occurred before
it.
False
Students will often think that if the
first child is a boy, then the next child
will be a girl. Each probability
occurrence for each event is
independent of the events that
occurred before it.
True or False
Every genetic trait is
controlled by only two
alleles.
False
Simple dominance is actually one of
the most rare forms of genetic
inheritance
Prior Knowledge
TEKS 7.10 – role of sexual reproduction in diversity
TEKS 7.10B inherited traits are contained in the DNA of
cells and expressed by genes
TEKS 7.10C distinguish between dominant and recessive
TEKS 6.11 B&C – changes in DNA at the phenotypic level
can occur through mutation and selective breeding
PUNNETT SQUARES
• GENE – A segment of DNA on a
chromosome that codes for a specific
trait.
• ALLELES – the different forms of a gene.
• HYBRID – An organism that has two
different alleles for each trait.
• TRAIT – A characteristic an organism can
pass on to its offspring through its genes.
Bb X Bb
Phenotypic Ratio
3:1
Genotypic Ratio
1:2:1
B
B
BB
b
Bb
b
Bb
bb
Prior Knowledge
Review 6th and 7th grade TEKS
Use DRAGON GENETICS kit
Tongue Rolling
Earlobes
Earbump
• Often called Darwin’s Ear Bump
• Dominant - Having a small bump on the
ear
• Recessive - Not having the bump
Widow’s Peak
Hitchhiker’s Thumb
Polydactyly
Syndactyly Feet
Syndactyly Hands
Syndactyly Surgery
Cleft Chin
Clockwise Hair Whorl
Autosomal Dominant and
Recessive
• Huntington Disease – Dominant Disease
• Cystic Fibrosis – Recessive Disease
Sickle Cell Anemia
Tay-Sach’s
PKU
ENGAGE
Show GATACA movie outtake
Explore
Use various modes to explore
probability.
• Playing Cards
• Spinners
• Dice
• Coins
 Explain
Record results on a master data table.
Discuss the difference between
experimental probability and theoretical
probability. Compare for different
attempts. Answer and discuss questions.
Elaborate
• Interactive Dragon Genetics monohybrid cross
practice problems
Dragon Punnett Squares
• Homework – completion grade on activity sheet
“More Monohybrid Crosses”
• Out of class experiments (select one of two
activities)
• Create brochure about genetic disorders
Evaluate
• Different evaluation methods will be used
to evaluate the many different activities
performed for this TEKS.