Dominant/Recessive - Lake Worth Community High School

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School District of Palm Beach County
K-12 Curriculum
‘TIS THE SEASON FOR SCIENCE
Science Winter Packet 2011-2012
Natural Selection & Genetics | Biology I
Teacher Introduction
The usage and implementation of the activities contained in the winter packets are optional and
voluntary. The activities were selected based on traditionally difficult areas of student mastery
while at the same time providing highly engaging and fun discovery.
Suggested ways to implement the winter packet:

Extra Credit

Team projects

Mini science project
Suggested alternatives to winter break activities:

FCAT Explorer
http://www.fcatexplorer.com

FCAT FOCUS Benchmark Mini-Assessments
http://focus.florida-achieves.com

Gizmos (Title 1 Schools and Schools that have purchased)
http://www.explorelearning.com/
Suggestions for checking for comprehension:




Review assessment questions attached to each winter packet
Discuss student findings after students return to school
Provide students an extension to the packet (Research paper, project, FCAT
Explorer, Gizmos, etc…)
Utilize FCAT FOCUS mini-assessments when students return to school
Introduction
Who would have ever guessed that science could be so much fun! Hands-on
experiments, discovery of cause and effect relationships, and engaging activities
have captured students’ interests in classrooms for years. However, classrooms and
laboratories aren’t the only places to experience the joys of science. This winter
packet has been provided with just that in mind. Students, you have the
opportunity to share the fun of scientific experiments and discoveries at home with
family and friends!
What is Science?
The study of science is designed to help discover information about the natural
world in which we live. Although it is a means of collecting facts (data) through an
organized and reproducible manner, science includes observations, predictions,
questions, trials and errors. In other words, it is a method for providing
understanding to an ever changing world.
Science does not provide all the answers. However, answers gathered through
inquiry using the scientific method explain daily events. Therefore, the great thing
about science is that anyone who studies it is exposed to new discoveries all the
time.
Purpose of the Winter Packet
The activities in the winter packet were selected to allow students to
experience science fun over the winter break while simultaneously
supporting the traditionally difficult areas of student mastery. This method
of home-school academic connection is a great means to maintaining
acquired skills while students are enjoying their winter break.
Activities in this packet are identified by Next Generation Sunshine State
Standards specifically targeted to grade level expectations for the students.
Each activity has been selected due to its high level of engagement and
interest. Background information is included for each activity in order to
provide students with a supportive platform to complete the contents of the
packet.
Biology Winter Packet
Name: ______________________________________________________
Section: ________
Part 1
SC.912.L.15.13 AA Describe the conditions required for natural selection, including: overproduction of
offspring, inherited variation, and the struggle to survive, which result in differential reproductive
success.
Part 2
SC.912.L.16.1 AA Use Mendel’s laws of segregation and independent assortment to analyze patterns of
inheritance.
SC.912.L.16.2 as AA Discuss observed inheritance patterns caused by various modes of inheritance,
including dominant, recessive, co-dominant, sex-linked, polygenic, and multiple alleles.
Part I - Natural Selection Evolution Lab
General Overview:
Charles Darwin is universally associated with evolutionary theory. His major contribution was to
describe the primary mechanism by which it worked: natural selection. Darwin said that it is the forces
of nature that select species to survive that are best adapted to the environment. These species in turn
produce offspring and their numbers increase. Darwin proposed four tenets by which natural selection
operates:
1. Genetic variation.
2. Overproduction of offspring.
3. Struggle for existence.
4. Differential survival and reproduction.
In this lab, you will complete two exercises that illustrate natural selection.
I. Mimicking Natural Selection
Introduction:
We infer from the fossil record that species evolve over time. Darwin argued that the primary
mechanism of evolutionary change is the process of natural selection. Natural selection occurs because
individuals with certain traits or adaptations have greater survival and reproduction than individuals
who lack those traits or adaptations. Selection that favors one extreme characteristic over the other is
known as directional selection. When selection favors an intermediate characteristic rather than one of
the extremes, it is known as stabilizing selection. Selection that operates against the intermediate
characteristic and favors the extremes is called disruptive selection.
In this exercise, you will use a simulation to study how natural selection works by looking at the survival
rate of differently colored “prey” in a pond. The prey will be represented by different colored beads.
Dark green and clear colored beads (different colored beans from a mixed bean soup dry mix could be
substituted) represent the two extreme characteristics, while light green colored beads represent the
intermediate characteristic. The “predator” will be represented by forceps used to catch the prey.
Materials:
- dishpan
- dark green/light green/clear beads (starter bean soup mixture as replacement, select
comparable colored beans)
- blue, red, and green food coloring,
- forceps (pliers or tongs may substitute as replacement)
- stopwatch or watch with second hand and someone to help record time.
Procedure:
1. You will establish the initial population by placing 10 dark green, 10 light green, and 10 clear beads
into a dishpan filled ¾ full of water that has been darkened with blue, red, and green food coloring. The
water should appear dark brown.
2. You will play the role of the predator. The predator searches the pond and removes as many prey as
possible in 30 seconds. In order to more closely model the handling time required by real predators, you
must search for and remove beads with forceps.
3. Count the number of each prey color removed and record it in Table 1. Calculate the number of
surviving prey for each color. Also calculate the prey’s reproductive success by adding 1 offspring for
each surviving prey. Add the offspring to the surviving population of prey in the pond. This will be your
new population in the next generation.
4. Repeat steps 2 – 3 six more times for a total of seven generations. Note – do not add any new
offspring after the 2nd generation.
5. Record your data in the tables present in the Mimicking Natural Selection Worksheet and complete
the packet.
Mimicking Natural Selection Worksheet
1. Record your results in the tables provided.
Table 1. First Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Dark bean/bead
10
Medium bean/bead
10
Light bean/bead
10
Dark bean/bead
Medium bean/bead
Light bean/bead
Dark bean/bead
Medium bean/bead
Light bean/bead
Dark bean/bead
Medium bean/bead
Light bean/bead
Table 2. Second Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Table 3. Third Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Table 4. Fourth Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Table 5. Fifth Generation
Dark bean/bead
Medium bean/bead
Light bean/bead
Dark bean/bead
Medium bean/bead
Light bean/bead
Dark bean/bead
Medium bean/bead
Light bean/bead
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Table 6. Sixth Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
Table 7. Seventh Generation
Initial population
Killed prey
Surviving prey
Number of Offspring
Next generation total
number
2. Make a bar graph showing the initial population of the first generation and the final
population size of the seventh generation for each color. Attach the graph to this
worksheet.
3. Which “prey” did you first hypothesize would survive and reproduce? Why? Provide
a rationale for your hypothesis.
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4. What type of selection—directional, stabilizing, or disruptive—did you observe? Did
your results support your hypothesis? If the water had been clear, would your
results have been different? Explain why or why not.
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5. Apply what you’ve learned: Research “predator/prey relationships” on the Internet
and find an example of how this exercise might apply to real organisms. Describe
how your results illustrate the example you have chosen. Provide the reference(s)
of the Internet source(s) that you used at the bottom of your description. _________________________
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Part IIA - Mendelian Genetics
INTRODUCTION:
Gregor Mendel discovered that many inherited physical traits are determined by a single pair of alleles,
or alternative forms of the same gene. An allele may be dominant, where the characteristic is exhibited
with a single copy, or recessive, where two copies of the same allele are required for the trait to be
seen. A dominant allele is usually designated with a capital letter and a recessive allele designated with
a lower case letter. If both alleles for a trait are the same (both dominant or both recessive), the
condition is called homozygous (pure). If the alleles for a trait are different (one dominant and the other
recessive), the condition is called heterozygous (hybrid). This set of alleles belonging to an individual
refers to an individual’s genotype. The resulting set of traits that an individual shows is called their
phenotype.
LABORATORY SET-UP:
For each trait, you will determine if you show the trait or not (phenotype), and then you will determine
what your genetic make-up is for that trait is (genotype). Next, determine whether each of your parents
show the trait and what their genotypes are. Even if you don’t know whether they show a particular
trait, you may be able to figure it out based on your genotype. Set up some Punnett squares to help you
do this. You can learn a lot about you and your family’s genetic make-up through this exercise. If you
don’t feel comfortable examining your family history an alternative family traits worksheet will be
provided. You will then practice using the Punnett square to determine some hypothetical genetic
family outcomes. Finally, you will get some additional practice using Punnett squares to set up
monohybrid and dihybrid crosses.
DESCRIPTIONS OF TRAITS:
1.
Widow’s peak: When the hairline dips down to a point in the center of the forehead. This is a
dominant trait (W). A continuous hairline is recessive (w).
2.
Dimpled chin: Depression or dimple in the chin is dominant (C). Its absence is recessive (c).
3.
Dimpled cheeks: Presence of dimples in one or both cheeks is dominant (D). Absence of
dimples is recessive (d).
4.
Rolling the Tongue into a “U”: The ability to roll the tongue into a “U” is dominant (U). The
inability to roll the tongue is recessive (u).
5.
Roman nose: A high convex bridge (Roman nose) is dominant (R) and a flat or concave nose is
recessive (r).
6.
Interlocking fingers: When clasping your hands together, your left thumb on top is dominant
(G). Right thumb on top is recessive (g).
7.
Ear lobes: Free (unattached) ear lobes are dominant (A), attached lobes are recessive (a).
8.
Pigmented irises: The absence of pigment in the inner lining of the eye results in blue or gray
eyes, a recessive trait (e). Brown, hazel, or green eyes are dominant (E).
9.
Mid-section finger hair: The presence of hair on the middle section of your 3rd (middle) or 4th
(ring) finger is dominant (H). The absence of hair is recessive (h).
10.
Freckles: Copious amounts of freckles are dominant (K). Skin without freckles is recessive (k).
Name: _______________________________________________________ Section: ________________
Family History Worksheet
Trait
Widow’s
peak
Dimpled
chin
Dimpled
cheeks
U shaped
tongue
Roman nose
Interlocking
fingers
Attached
earlobes
Pigmented
irises
Mid-section
Finger hair
Freckles
Your
Phenotype
(Do you
have the
trait)
Your
Genotype
(AA, Aa, or
aa)
Mother’s
phenotype
Mother’s
genotype
Father’s
phenotype
Father’s
genotype
Name: ____________________________________________________________ Section: ___________
Alternative Family Traits Worksheet
Trait
Widow’s
peak
Dimpled
chin
Dimpled
cheeks
U shaped
tongue
Roman nose
Interlocking
fingers
Attached
earlobes
Pigmented
irises
Mid-section
Finger hair
Freckles
Your
Phenotype
(Do you
have the
trait)
No peak
No dimpled
chin
No dimpled
cheeks
Yes – can
roll into U
No Roman
nose
Left over
right
No – have
free lobes
Yes –
pigmented
No mid-digit
hair
No freckles
Your
Genotype
(AA, Aa, or
aa)
Mother’s
phenotype
Mother’s
genotype
Father’s
phenotype
No Peak
No peak
No dimpled
chin
No dimpled
cheeks
Yes – can
roll into U
No Roman
nose
Left over
right
No – have
free lobes
Yes –
pigmented
No mid-digit
hair
No freckles
No dimpled
chin
No dimpled
cheeks
No – can’t
roll into U
No Roman
nose
Left over
right
No – have
free lobes
Yes –
pigmented
No mid-digit
hair
No freckles
Father’s
genotype
Part IIB
NAME:__________________________________________________
SECTION:________
BACKGROUND: A long time ago, in a galaxy far, far away, a great race of beings lived on a planet called ZORK.
The inhabitants were known as Zorkonians. They are made up of 10 basic genes (unit) that code for their
appearance. Each one of these genes is made up 2 alleles (traits). With this in mind, there are 1,024 different
possible combinations for their appearance! This is called their phenotype or their physical appearance. If we look
at their genes, there are 59,049 different combinations of the alleles! This is called the genotype or genetic makeup.
Remember that we use letters for the alleles that control the genes and one letter or allele is inherited from each
parent. You will be using Zorks, who use the same genetic principles as a pea plant, to see how genes are passed
on and inherited. You will be using Punnett Squares to do this.
Here are some things to help you. You must understand these concepts and terms! I will use traits from the table on
the next page as examples.
Phenotype: The physical appearance or what the gene makes an organism look like. Examples would be two eyes,
yellow hair, and green lips from a zork.
1. Dominant: The trait that is shown the most. Example: Green hair is dominant over yellow hair.
2. Recessive: The trait that is hidden. In this example: yellow hair.
Genotype: The genetic makeup of an organism. We use letters for the genotype. Remember that you need to look
at the genotype to see what the phenotype will be.
Example: There is a Gene or unit for hair color in a zork. The alleles or traits (individual genes) for hair color would
be yellow and green. There are 2 alleles for each gene and we use letters for each allele. The capital letters are the
dominant alleles and the lower case letters are the recessive alleles.
Gene
Hair color
Allele
1. Green color = G
2. Yellow color = g
1. Heterozygous (Hybrid): The term used for different alleles. There is always one dominant and one recessive
allele. Example: Gg. There is only one possibility for this!
2. Homozygous (Pure): The term used for having the same alleles. This will be either 2 dominant alleles or 2
recessive alleles. Example: GG or gg. There are 2 possibilities for this!
Please refer back to this to help you as you work through this assignment. You will use the table on the next page to
complete the problems that follow. Everything you need is in the table! The following are the traits of a Zork, which
we will use to study genetics. You will be studying one family. Be sure to read each problem carefully, because in
each case the information is built upon the previous problem.
Allele
Trait
Tall
Dominant/Recessive
Dominant
Genotype
TT,Tt
Phenotype
Tall
t
Short
Recessive
Tt
Short
G
Green hair
Dominant
GG,Gg
Heterozygous
Tt
Homozygous
TT
tt
Green
Gg
GG
Hair
Yellow
g
Yellow hair
Recessive
gg
gg
Hair
E
One Eye
Dominant
EE,Ee
One Eye
e
Three Eyes
Recessive
ee
Three Eyes
F
One Fang
Dominant
FF,Ft
One Fang
f
Two Fangs
Recessive
ff
Two Fangs
H
Two Horns
Dominant
HH,Hh
Two Horns
h
One Horn
Recessive
hh
One Horn
L
Purple Lips
Dominant
LL,Ll
Purple Lips
l
Green Lips
Recessive
ll
Green Lips
W
Two Wings
Dominant
WW,Ww
Two Wings
w
No Wings
Recessive
ww
No Wings
N
One Leg
Dominant
NN,Nn
One Leg
n
Two Legs
Recessive
nn
Two Legs
R
Green Skin
Dominant
RR,Rr
Green Skin
r
Yellow Skin
Recessive
rr
Yellow Skin
B
Thick
Eyebrow
Dominant
BB,Bb
Thick Eyebrow
b
Thin
Eyebrow
Recessive
bb
Thin Eyebrow
Ee
EE
ee
Ff
FF
ff
Hh
HH
hh
Ll
LL
ll
Ww
WW
ww
Nn
NN
nn
Rr
RR
rr
Bb
BB
bb
SINGLE CROSS PROBLEMS
1. Cross a heterozygous green skinned zork with a yellow skinned zork.
A. What do the possible offspring look like?
2. Cross a homozygous two horned zork with a heterozygous two horned zork.
A. What are the genotypes of the possible offspring?
3. Cross a heterozygous green haired zork with a heterozygous green haired zork.
A. What are the genotypes and phenotypes of the possible offspring?
4. Cross a green lipped zork with a heterozygous purple lipped zork.
A. What are the number of phenotypes and genotypes of the offspring? Hint: Count what is in the
boxes!
5. Tork, who is homozygous for tall meets Vorkina, who is short.
A. What are the phenotypes and genotypes if they were to have offspring?
6. Tork and Vorkina have two children. One is a boy named Torky and the other is a girl named Vorki. Many years
later, Torky meets and marries a girl named Morkalina who is short.
A. What are the possibilities for the height of their offspring?
Hint: Look at 5A for information on Torky.
7. Vorki the daughter meets a zork named Spork, who is heterozygous for tall.
A. How many will be tall? How many will be short? How many will be TT?
How many will be Tt? How many will be tt?
8. Torky has green hair and Morkalina has yellow hair. They have four children and all of them have green hair.
What phenotype and genotype must Torky be?
9. Spork and Vorki both have three eyes.
A. What would their offspring look like?
10. Using problems 5-9, give the phenotypes and genotypes of Tork, Vorkina, Torky, Morkalina, Spork and Vorki
based ONLY on the traits given in the problems.
Packet Questions
1. A species of mockingbird lives in the Apalachicola National Forest. One year, a few of the
mockingbirds were born with very long beaks. Over the next several years, the area experienced
particularly cold winters. The weather forced the insects in the area to burrow deeper into the
ground. Surveys of the mockingbird population showed that the number of long-beaked
mockingbirds had increased. What would account for this increase in the number of long-beaked
mockingbirds?
A.
B.
C.
D.
Short-beaked mockingbirds migrated to warmer climates.
Short-beaked mockingbirds became food for other animals.
Long-beaked mockingbirds were able to reach food and survived.
Long-beaked mockingbirds were able to stay warmer during the cold winters.
2. Under some conditions, such as a lack of natural predators, a species may experience an increase in
reproductive success and produce a very large number of offspring. Which of the following is the
most likely consequence?
A. The species will experience a decrease in its physical capability to reproduce in future
generations.
B. Some of the individuals will breed with closely related species, increasing the genetic diversity
within the population.
C. Individuals who are better able to compete for resources will survive and pass on the traits that
enabled survival to their offspring.
D. The species will be better equipped to defend its territory against other species, and its
population will increase even more.
3. Under some conditions, such as a lack of natural predators, a species may experience an increase in
reproductive success and produce a very large number of offspring. Which of the following is the
most likely consequence?
A. The species will experience a decrease in its physical capability to reproduce in future
generations.
B. Some of the individuals will breed with closely related species, increasing the genetic diversity
within the population.
C. Individuals who are better able to compete for resources will survive and pass on the traits that
enabled survival to their offspring.
D. The species will be better equipped to defend its territory against other species, and its
population will increase even more.
4. In human eye color, B represents the dominant brown eye gene and b represents the recessive blue
eye gene. If two parents have the genotypes Bb and BB, what is the likelihood that a child from
these parents would have blue eyes (genotype bb)?
A.
B.
C.
D.
0 percent
50 percent
75 percent
100 percent
5. Two parents are about to have a child. Both the mother and father have brown hair and are
heterozygous for brown hair color; their genotypes are both Bb, where B represents the dominant
brown hair allele and b represents the recessive blond hair allele. What are the possible genotypes
for their child's hair color?
A.
B.
C.
D.
BB, Bb, bb
BB only
Bb only
Bb and bb only
The three different activities were pulled from a variety of sources.
The Natural Selection Evolution Lab and Mendelian Genetics activities
were taken from www.tmcc/biology/downloads and administered by
Truckee Community College.
The Zork Genetics were taken in its entirety from www.ndark.net and
supplied by Roger Moore from Wooster High School in Reno, NV.
All credit for these activities belong to the above listed authors and
sources.
Packet questions were taken from FCAT Explorer Science Mission.
MISSION STATEMENT
The School Board of Palm Beach County is
committed to excellence in education and
preparation of all our students with the knowledge,
skills and ethics required for responsible citizenship
and productive employment.
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