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GENETICS UNIT
GENETICS ......................................................................................................................... 1
Lesson 1: Introduction to Genetics ................................................................................. 2
Rationale: .................................................................................................................... 2
Objectives: .................................................................................................................. 2
Materials: .................................................................................................................... 3
Procedure: ................................................................................................................... 3
Extensions: .................................................................................................................. 4
Feedback: .................................................................................................................... 4
Lesson 2: Punnett Squares, Genotypes and Phenotypes ................................................. 4
Rationale: .................................................................................................................... 4
Objectives: .................................................................................................................. 4
Materials: .................................................................................................................... 4
Procedure: ................................................................................................................... 4
Questions: ................................................................................................................... 5
Lesson 3: Two Traits ...................................................................................................... 5
Rationale: .................................................................................................................... 5
Objectives: .................................................................................................................. 5
Materials: .................................................................................................................... 5
Procedure: ................................................................................................................... 5
Questions: ................................................................................................................... 6
Extensions: .................................................................................................................. 6
Feedback: .................................................................................................................... 6
Lesson 4: Probability and Genetics................................................................................. 6
Rationale: .................................................................................................................... 6
Objectives: .................................................................................................................. 6
Materials: .................................................................................................................... 6
Procedure: ................................................................................................................... 7
Questions: ................................................................................................................... 7
Lesson 5: Multiple alleles ............................................................................................... 7
Rationale: .................................................................................................................... 7
Objectives: .................................................................................................................. 7
Materials: .................................................................................................................... 7
Procedure: ................................................................................................................... 7
Extension: ................................................................................................................... 8
Questions: ................................................................................................................... 8
Feedback: .................................................................................................................... 8
Lesson 6: Genetics Brainteaser ....................................................................................... 9
Rationale: .................................................................................................................... 9
Objectives: .................................................................................................................. 9
Materials: .................................................................................................................... 9
Procedure: ................................................................................................................... 9
Questions: ................................................................................................................... 9
Lesson 7: Chromosome Theory of Heredity................................................................... 9
Rationale: .................................................................................................................... 9
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Objectives: .................................................................................................................. 9
Materials: .................................................................................................................. 10
Procedure: ................................................................................................................. 10
Questions: ................................................................................................................. 11
Feedback: .................................................................................................................. 11
Lesson 8: Many Genes One Effect ............................................................................... 11
Rationale: .................................................................................................................. 11
Objectives: ................................................................................................................ 11
Materials: .................................................................................................................. 11
Procedure: ................................................................................................................. 11
Questions: ................................................................................................................. 11
Lesson 9: Predicting Genotypes.................................................................................... 12
Rationale: .................................................................................................................. 12
Materials: .................................................................................................................. 12
Procedure: ................................................................................................................. 12
Questions: ................................................................................................................. 13
Feedback: .................................................................................................................. 13
Extensions: ................................................................................................................ 13
Lesson 10: Expression of Genes ................................................................................... 13
Rationale: .................................................................................................................. 13
Objectives: ................................................................................................................ 13
Materials: .................................................................................................................. 13
Procedure: ................................................................................................................. 13
Extensions: ................................................................................................................ 14
Questions: ................................................................................................................. 14
Feedback: .................................................................................................................. 14
Lesson 11: Heredity and Genetics Exam ...................................................................... 14
Multiple Choice (2 pts each) ..................................................................................... 14
Short Answer (5 pts each) ......................................................................................... 17
Comprehension (10 pts each).................................................................................... 17
Lesson 1: Introduction to Genetics
Rationale:
This lesson will give the students a basic introduction to genetics. This introduction will
serve as the backbone for this unit and will give the students a basic idea of what they can
expect.
Objectives:
To explain the differences between five different species of fish. (comprehension)
To recognize the connection between these fish and genetics. (analysis)
To identify Gregor Mendel as the founder of genetics and his accomplishments.
(analysis)
To explain Mendel's experiments with pea plants. (comprehension)
Know how sample size affects data and give examples. (knowledge)
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To state the definitions of dominant and recessive genes and hereditary traits.
(knowledge)
Materials:
5 different species of fish (any kind will do), five plastic containers, overhead
transparency of Mendel's experimental traits chart
Procedure:
1. Set up 5 different plastic containers each containing a different fish. Have
students observe the fish and ask them what similar features they share (eyes,
scales, fins, etc.). What are the differences among them (size and color of scales,
size, shape, and number of fins). When this is completed, discuss with them their
observations. Ask them why they think fish have different characteristics? Why
do some have large scales and others don't? Explain that they have described
some inherited traits found in fish. Some of these traits are similar because they
are defining characteristics of all fish. Tell them that they will learn more about
how they inherit these traits in this unit. (10 min.)
2. Origin of Genetics (5 min)
The basis of what we know came from the work of Gregor Mendel (1822-1884).
He was a monk in a monastery who later went to Vienna to study science and
mathematics and become a teacher. He returned to the monastery after only two
years which is when he started to tend the monastery garden and experiment with
plants. He published his results in 1866 after many years of experimenting and
analyzing. This work was ignored until 1900 when it was finally recognized as a
major development in biology.
3. Mendel's Experiments (20 min)
Mendel worked with the pea plant because they are grown easily and produce a
large number of offspring in a short time. He found that certain pea plants had
characteristics that remained unchanged from one generation to the next. Ask the
students to hypothesize about why they think this is. An example would be that
pea flowers are either purple or white.
hereditary: characteristics that are passed from generation to generation
His work was devoted to how these traits were transmitted from parent to
offspring. He chose traits of the peas that were easy to test and also studied the
offspring of two generations instead of one. Mendel also worked with a large
number of plants to increase the chances of his results. The seven traits he chose
were seed shape, seed color, flower color, flower position, pod color, pod shape,
and plant height. (display on overhead) What do they notice about the chart? Point
out how some traits are dominant and others are recessive.
dominant trait: this will be expressed because it dominates or prevents the
recessive trait from being expressed. Ex. If you cross purple (W, dominant trait)
flower with a white flower (w, recessive trait), you will get all purple flowers.
recessive trait: The trait will not be expressed unless crossed with another
recessive trait
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4. How does sample size affect results? (15 min)
Have the students count up the number of males and females in the classroom.
What is the ratio of males to females? (total males/total students in the class x
100%). Explain to them that the ratio of males to females born in a population
should be 50/50. If the class does not display this it is because it is a very small
sample size. Have them redo this count but now count the number of brothers and
sisters each classmate has also. How does this compare to the first sample?
Explain that as sample size increases, observed data will come closer to the 50:50
ratio. That is why Mendel used large sample sizes when studying the pea plants.
5. Read pages 198-205
Extensions:
If time permits, introduce a blank Punnett square with a WW (purple) and ww (white)
cross.
Feedback:
The feedback for this lesson would be obtained through the questioning process during
lecture.
Lesson 2: Punnett Squares, Genotypes and Phenotypes
Rationale:
Punnett squares are used to determine specific outcomes of genotype crosses. The
Predicting Plant Genotypes lab will help them to use their powers of observation and
their knowledge of punnett squares to predict the plant genotypes.
Objectives:
Solve punnett square problems in F1 and F2 generations. (synthesis)
List the definitions of punnett squares, allele, genotype, phenotype, homozygous, and
heterozygous. (knowledge)
After the lab is completed:
Students will observe and record colors of offspring from three different parental
genotypes. (application)
Determine parental genotypes based on ratios of observed phenotypes. (synthesis)
Materials:
Overheads of punnett squares, petri dishes, small pots or milk cartons, small paper cups,
soil, sand, tobacco seeds, vermiculite or Readi-Earth, labels, marking pens, paper towels,
and scissors.
Procedure:
1. Definitions (10 min)
Punnett Square, allele, genotype, phenotype, homozygous and heterozygous traits.
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2. Punnett Squares (15 min)
Draw Crosses of WW x ww, WW x Ww, and Ww x Ww
Step by step process of Mendel's test of segregation
Are their any questions about any of this.
3. Lab
Predicting Plant Genotypes
Explain purpose of lab (pg 204-205)
Give instructions
Divide them into groups of four
Plant seeds
Questions:
What is your hypothesis going to be for your plant seeds?
What are the possible ways you might test your hypothesis?
How are you going to test it?
What data are you going to collect?
How long are you going to collect data for?
Have you designed a table to record data?
What are your groups responsibilities?
Lesson 3: Two Traits
Rationale:
After Mendel's first experiments, he studied the inheritance of two traits at once. The
students will use punnett squares to determine the outcomes of such crosses.
Objectives:
Predict the phenotypic and genotypic ratios of a two trait cross. (application)
Design a concept map for this first section of material relating concepts together.
(synthesis)
Students will have their choice as to what they will do for assessment. (affective
responding)
Materials:
Blank overhead transparencies
Procedure:
1. Explain that a two trait cross involves something such as a parent plant that
produced peas that were round and yellow (RRYY) and a parent plant that
produced peas that were wrinkled and green (rryy). Ask students what they
believe will be the outcome of this cross? In the F1 generation, all offspring will
be RrYy. However what would happen if you crossed an RrYy with an RrYy?
Display this on a punnett square on the overhead. What is the phenotypic ratio
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2.
3.
4.
5.
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(9:3:3:1)? What are the genotypes of these plants? These are nine different
genotypes and four phenotypes. (20 minutes)
Give the students a dyhibrid problem to see if they are able to determine the
gametes. Give them a cross of PPTt x PpTT where P=purple, p=white, T=Tall,
and t=short. Why don't you get a 9:3:3:1 ratio? Give several more problems for
them to complete and ask for volunteers to displat their results on the overhead.
(20 minutes)
The students will be assigned the questions at the end of the section on page 206.
They can either answer those questions or compose a concept map using terms
from this section and present them to the class. (5 min)
Have students check their seeds. (5 min)
Read pages 207-211
Questions:
Explain how two black mice when mated, can produce some offspring that are white?
Apply the law of segregation to explain the kinds of gametes produced by an animal that
has the genotype Aa.
One parent is homozygous for a certain trait, and the other is heterozygous, What fraction
of their offspring would you expect to be heterozygous?
The offspring of a cross between two red-flowered plants show a ratio of three redflowered plants to one white-flowered plant. Which trait is dominant? What must the
genotypes of the parents be?
In pea plants, tall is dominant over short. Suppose you have a tall plant but dont know
whether it is homozygous or heterozygous. How could you find out?
Extensions:
Instead of letting the class choose, have them all turn in concept maps and do a
presentation on them.
Feedback:
The concept maps and questions would be collected to give me an idea of how much the
students comprehend.
Lesson 4: Probability and Genetics
Rationale:
Students will relate how probability is used to solve genetics problems.
Objectives:
Apply the rules of probability to solve genetics problems. (application)
Demonstrate the inheritance of traits resulting from incomplete dominance, codominance,
and multiple alleles. (analysis)
Materials:
paper bags, kidney beans, pinto beans, coins and plain transparencies
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Procedure:
1. Probability and Genetics
Coin Toss Activity
Kidney Activity (p 207)
2. Definitions
Incomplete dominance, multiple alleles
3. Punnett Squares
Fruit flies
Male Heterozygous straight=Ss
Female Heterozygous straight=Ss
Punnett squares display probability
4. Incomplete Dominance Punnett Square
5. Check on seeds
Questions:
What ratio of head and tail combinations might you expect if you toss two coins
together?
What are the ratios of phenotypes in the offspring of the fruit flies?
What genotypic and phenotypic ratios could you expect if you cross a red four o'clock
and a pink four o'clock?
Lesson 5: Multiple alleles
Rationale:
Students have learned that two alleles act together to produce a phenotype. Although each
organism normally has just two alleles for a trait, more that two alleles may be possible
for that trait in the population.
Objectives:
Students will list the definitions of codominance and multiple alleles.(knowledge)
Students will explain the difference between codominance and incomplete dominance
and examples of how these words relate to each other. (affective responding)
Will be able to solve questions regarding probability of ratios and other terms in this unit.
(synthesis)
Materials:
N/A
Procedure:
1. (Lecture 20 minutes) Draw two lines on the chalkboard to represent two
chromosomes. Place three different genes on each chromosome. Point out that
these are what we call multiple alleles because more than two alleles control the
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trait.
multiple allele: set of three or more different alleles controlling a trait.
In humans, three alleles determine blood type IA, IB, ad i. IA and IB are
dominant over i, but IA and IB are codominant.
codominance: results when one allele in not dominant over the other and both
alleles are expressed equally.
The four blood phenotypes are A B and O. The genotypes are IAIA or IAi for
blood type A. IBIB or IBi for blood type B. IAIB for blood type AB and ii for
blood type O. Solve this problem: A woman having blood type O blood married a
man having type AB blood. What are the expected genotypic and phenotypic
ratios among their children? Use a punnett square. (IAi, or IBi)
A woman who has type B blood marries a man who has type A blood. They have
five children, all with type AB blood. What are the most probable parental
genotypes? Mother could be IBIB or IBi. Father could be IAIA or IAi but if all
five children are IAIB then both parents must be homozygous.
Rabbit color is also determined by multiple alleles.
2. Students will then work on the section review questions for the remainder of the
class period.
3. Check on seeds.
Extension:
For students still having problems, take them off in a small group and work with them on
punnett squares or whatever else they may need help on.
Questions:
What are the chances of tossing four pennies at the same time and having them all come
up tails?
What genotypic ratio could you expect from a cross between an organism having the
genotype Dd and an organism with the genotype DD?
Watermelons with a round shape are crossed with those having a flatter shape. Some
offspring have an oval shape. Explain.
In guinea pigs, rough coat (R) is dominant over smooth coat (r), and black (B) is
dominant over albino (b). Make a pie graph showing the ratio of different genotypes
expected when a guinea pig having the genotype BbRr is crossed with one having the
genotype bbRr.
A man with blood type B marries a woman with blood type A. Their first child has blood
type O. Explain. What other blood types are possible for their future children?
Feedback:
The students will hand in the answers to these questions and I will also be able to assess
by the difficulty they have in answering these. Another useful thing will be for me to see
how many students come forward for individual help on this day.
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Lesson 6: Genetics Brainteaser
Rationale:
This crossword puzzle will give the students a chance to test their problem solving skills.
I have not given out all of the information needed on this worksheet so they will have to
use other resources to find the answers.
Objectives:
Students will use their problem solving skills to complete the worksheet. (analysis)
Summarize the cloning of Dolly the sheep (comprehension)
Use judgment to evaluate the ethical value of cloning (evaluating)
Materials:
VCR and TV, video of Dolly the Sheep, Crossword puzzle, sample problems worksheets,
dictionaries, and textbooks
Procedure:
1. Hand out Worksheet
Explain the directions
2. Video on Dolly the Sheep
Discussion
3. Read pages 212-221
4. Hand out Two sheets of sample punnett square problems
Questions:
Do you like doing worksheets like this for a change?
How do you feel about cloning?
What do you think this means for our future?
How does this video pertain to what we are studying?
Do you think cloning should be done?
Lesson 7: Chromosome Theory of Heredity
Rationale:
Students will describe the chromosome theory of heredity and relate how it helped
biologists develop an understanding of sex determination in animals. They will compare
and contrast inheritance patterns in sex linked genes, multiple genes, and modifier genes
with patterns of inheritance according to Gregor Mendel.
Objectives:
Apply the laws of probability to solve genetic problems involving sex-linked traits.
(applying)
Explain sex-linked inheritance and sex determination when talking about crosses.
(comprehending)
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Materials:
N/A
Procedure:
1. Gregor Mendel explained simple patterns of inheritance without knowing of the
existence of chromosomes. Not until the early 1900s did scientists begin to
connect cellular processes and genetic principles to understand how genetic
information is transferred. I was now revealed through new techniques which
allowed scienteists to observe chromosomes in cells that each diploid cell has one
homologous pair of chromosomes of each type and that a zygote inherits both
homologous. Walter Sutton proposed that genes are carries on chromosomes. He
made this proposal after observing meiosis in grasshoppers.
Sutton saw that during meiosis, the chromosomes in each grasshopper cell lined
up in pairs and each pair was the same size and shape.
The homologous pairs of chromosomes segregate during meiosis so that each
gamete receives one chromosome form each pair.
When fertilization occurs, the resulting zygote has a full set of homologous
chromosomes.
Humans have 46 chromosomes but we have more than 46 inherited characteristics,
therefore he proposed that each chromosome must carry hundreds of genes. (15
min)
2. Drosophilae (fruit flies) have played a very important role in the study of genetics.
Thomas Hunt discovered that male and female Drosophila cells are slightly
different.
Sex Chromosomes: X and Y chromosomes that differ between the sexes
Autosomes: All other chromosomes
A female normally has three pairs of autosomes and two X chromosomes. A male
normally has three pairs of autosomes and a Y chromosome. (Illustration on
chalkboard). A cross between a female XX and a male XY will give you half
female and half male organisms. (15 minutes)
3. In 1910, Morgan also discovered that the sex of an organism can be related to
inheritance of a trait. He made this discovery studying eye color in fruit flies. He
then crossed a white-eyed male with a red-eyed female. In the F1 generation he
got three red-eyed flies to one white-eyed fly. But, in the F2 generation, he noted
that white-eyed flies in this generation were all male. Therefore aye color must be
a sex-linked trait.
Punnett square of White-eyed male (XrY) to Red-eyed female (XRXR). In the F1
you will get red-eyed males and red-eyed females. In the F2 generation will be
red-eyed males, white-eyed females, and white eyed males which explained his
previous data by showing how all white-eyed flies in the F2 generation had to be
males. (10 min)
4. Check on your seeds (5 min)
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Questions:
What do you think are some sex linked traits among other organisms?
Do you understand everything that I covered today?
Is there something that you want me to go over again from a previous day?
Feedback:
This would definitely be a day to watch expressions because of the difficulty of the
material. Confused looks will give it away. The questions asked will also help to get
more feedback about the lesson.
Lesson 8: Many Genes One Effect
Rationale:
This lesson will describe what happens when two pairs of genes determine a trait, that
many different phenotypes are possible in the F2 generation.
Objectives:
Students will solve a Punnett square cross between AaBb and AaBb and be able to
explain what is happening. (synthesis & comprehension)
Students will be able to distinguish between a gene cross and the previous crosses in this
unit. (analysis)
Materials:
transparencies
Procedure:
1. Punnett Square
Cross between AaBb and AaBb
What are the Phenotypic Ratios?
What are the Genotypic Ratios?
Give the Students Four more sample problems
2. Work on Seed Lab
Questions:
What are the phenotypic and genotypic ratios of a AaBb x AABb?
Why is this?
Can you explain this data?
Are you ready for your final recordings of your seeds?
How did you like predicting the phenotypes of the seeds?
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Lesson 9: Predicting Genotypes
Rationale:
This lesson is mainly for the students to b e able to understand their data acquired
throughout their investigation.
Materials:
The students will need their data tables
Procedure:
Give them the class period to work on these reports. Ask the students what they found in
their observations? Were their hypotheses correct? Have them get into their groups and
report answers on paper for the following questions.
Why was it necessary to grow the seeds into plants in order to read the seed's
phenotypes?
Using the information provided in the introduction regarding genotype and phenotypes,
describe the difference between the inheritance pattern of the green gene C and the green
gene G.
What were some of the variables that you had to consider in this experiment? Explain
how they could have influenced your data if not taken into account.
For the batch of seeds that provided all green plants, are you able to predict exactly the
genotypes of (a) the parents that formed these seeds? Explain. (b) Each plant observed?
Explain.
For the batch of seeds that provided some albino plants, are you able to predict exactly
the genotypes of (a) the parents that formed these seeds? Explain. (b) Of each plant
observed? Explain.
Answers
Seeds contain the genetic instructions for traits in an adult plant. Growing the seeds
allows these gene traits to be expressed.
The gene C is inherited as a completely dominant trait. The gene GG is inherited with a
pattern of incomplete dominance.
All plants had to receive the same amount of water. All plants would be placed in the
same type of soil. Nutrients in one soil type could influence or retard the growth of one
batch.
(a) No-parent plants may have been CC and CC or CC and Cc
(b) No-plants may be green with a Cc or CC genotype
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(a) Yes-the parents must have been Cc and Cc. These are the only possible parental
genotypes that will yield a 3:1 green to albino ratio of offspring.
(b) No for the green plants. They may have been CC or Cc. Yes for the albino plants.
They are all cc.
(a) Yes-parents both had to be GY. This is the only genotype combination that will yield
offspring with a 1:2:1 green to yellow green to yellow ratio of offspring.
(b) Yes-with incomplete dominance, each genotype has a corresponding phenotype.
Questions:
See above and there may be a wide variety of questions that come up during the hour.
Feedback:
I will get feedback in the form of their reports. This will tell me if they understand the
material or not.
Extensions:
Each group would do a report on their findings
Lesson 10: Expression of Genes
Rationale:
Students can now observe themselves and understand how their genes are expressed.
Objectives:
Students will apply their knowledge of heredity to their expression of their genes.
(application)
Students will give examples of genes they express. (comprehension)
Students will illustrate their knowledge of this topic by answering the section review
questions. (analysis)
Materials:
N/A
Procedure:
1. Lab
Students will give phenotypes and genotypes in themselves
Use these traits to wrap up the Unit
2. Section Review Questions
Discuss the with the class instead of assigning them
Ask questions
Help those who are still struggling
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Extensions:
For those students who understand, have them help their fellow classmates with sample
problems that you have given them.
Questions:
The questions at the end of the section and other questions on this day would be very
random and I would reserve this for them to ask me questions.
Feedback:
This discussion should give me a feel for how much they understand this unit. By
discussing the questions with them, I will be able to tell who comprehends the material.
Lesson 11: Heredity and Genetics Exam
Multiple Choice (2 pts each)
1. The basis of what we know about genetics came from the work of?
A. Walter Sutton
b. Gregor Mendel
c. Thomas Hunt Morgan
d. Joseph Monarch
2. Characteristics that are passed from generation to generation are?
A. dominant
b. recessive
c. hereditary
d. homologous
3. Gregor Mendel worked with what kind or plant?
A. corn
b. wheat
c. beans
d. peas
4. If you have the gene Ww where W represents purple flowers and w represents white
flowers, which one is the dominant trait?
a. W, or purple flowers
b. w, or white flowers
c. both a and b
d. neither a nor b
5. Each alternative form of a gene for a certain trait is called a(n)?
A. allele
b. genotype
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c. phenotype
d. recessive trait
6. The appearance of a trait as determined by a given genotype is called the?
A. genotype
b. phenotype
c. allele
d. dominant trait
7. The combination of alleles for a given trait is referred to as the?
A. genotype
b. phenotype
c. allele
d. gamete
8. When each cell of an organism contains two different alleles for a given trait the
organism is?
A. homozygous for that trait
b. heterozygous for that trait
c. dominant for that trait
d. recessive for that trait
9. A set of three or more different alleles controlling a trait are?
A. codominance
b. incomplete dominance
c. multiple alleles
d. none of the above
10. What results when one allele is not dominant over the other?
A. codominance
b. incomplete dominance
c. multiple alleles
d. heterozygous traits
11. A woman having blood type O (genotype ii) married a man having type AB blood
(genotype IAIB). What are the expected genotypic ratios among their children?
a. IAIA or IBIB
b. IAi or IBi
c. IA or IB
d. none of the above
12. A woman who has type B blood marries a man who has type A blood. They have five
children, all of which have type AB blood. What are the most probable parental
genotypes?
A. mother IBIB, father IAIA
b. mother IBi , father IAi
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c. mother IBIB, father IAi
d. mother IBi, father IAIA
13. Who proposed that genes are carried on chromosomes and also discovered that the
sex of an organism can be related to the inheritance of a trait?
A. Gregor Mendel
b. Walter Sutton
c. Thomas Hunt Morgan
d. Joseph Monarch
14. X and Y chromosomes are?
A. linked chromosomes
b. sex chromosomes
c. autosomes
d. none of the above
15. What genotypic ratio would you expect from a cross between an organism having the
genotype GG and an organism having the genotype Gg?
A. all GG
b. all Gg
c. half GG and half Gg
d. half GG and half gg
16. The probability of any one child being a boy is 1/2. What is the probability that five
children in a family will all be boys?
a. 1/64
b. 1/32
c. 1/16
d. 1/4
17. One parent is homozygous for a certain trait and the other is heterozygous. What
fraction of their offspring would you expect to be heterozygous?
a. 1/2
b. 1/4
c. 1/8
d. 3/4
18. A cross between a homozygous red horse and a homozygous white horse produces an
offspring with a coat coloring called roan. Examination of the roans coat reveals the
presence of both red and white hairs. How is this pattern of inheritance explained?
A. incomplete dominance
b. codominance
c. sex linked
d. homozygous traits
19. What is the probability that when tossing two coins, they will both end up heads?
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a. 1/4
b. 1/2
c. 1/8
d. 3/4
20. What are the phenotypes when crossing WW x Ww where W stands for purple
flowers and w stands for white flowers?
a. 1/2 purple, 1/2 white
b. all white
c. all purple
d. 1/2 WW and 1/2 Ww
Short Answer (5 pts each)
1. How does sample size affect results when sampling a population? Give an example.
2. Explain how two black cats, when mated, can produce some offspring that are white?
3. O is oriental eye shape
o is non-oriental eye shape
W is a widow's peak
w is no widow's peak
T is a tongue roller
t is no tongue rolling
Convert these three genotypes to phenotypes: OOwwTt, ooWwtt, and oowwTT.
Comprehension (10 pts each)
1. Draw a Punnett square for the following cross: AaBb x AaBb. Include the genotypic
ratios underneath the square.
2. Draw a Punnett square for the cross PPTt x PpTT where P=purple, p=white, T=tall,
and t=short. What are the phenotypic ratios?
For an alternative assessment besides the unit test, here are two ways that I would assess
my students.
1. Have them create a concept map either in the middle of the unit as described in my
lesson plans, or after the unit is finished. The criteria I would expect are the bold terms in
the chapter and the main points in each section. These concept maps would be graded as
pass fail (10 pts) because I would want to use them to see how much the students have
comprehended the unit. This would give me a chance to see who needs some extra help.
They would get ten points for handing a map in whether or not it is correct. However, it
must have one central idea and branch out from there with explanations between each
concept.
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WORLDISSQUARE
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2. The other alternative assessment would be to have the students turn a group report on
their findings from the predicting plant genotypes lab. These would include the group’s
initial hypothesis, data taken from each day the seeds were observed, their results and the
answers to the questions at the end of the lab on page 205. They would receive a group
grade (20pts total) depending upon if all of the components are included. They must also
be presented in a suitable manner, (neat, organized, typed (optional), etc. This would
show me how effective this lab was and what I could do to help the students understand
this concept.
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