GREGOR MENDEL
MEIOSIS
MENDEL, GENETICS, MEIOSIS
AND GENE TECHNOLOGY
Pre-AP PACKET - 2014
Name: ______________________
Period: ____
Teacher: ___________________
PUNNETT SQUARES
GENE TECHNOLOGY: DNA FINGERPRINTING
STUDENT UNIT PLAN LEARNING TARGETS: MEIOSIS, GENETICS and GENE TECHNOLOGY
VOCABULARY TERMS: Meiosis
Genotype
Homozygous
Dominant
Recessive
Phenotype
Purebred
Hybrid
Heterozygous
Allele
Chromosome
Punnett Square
Monohybrid Cross
Dihybrid Cross
offspring
Co-Dominance
Incomplete Dominance
Sex-Linked traits
Crossing Over
Mendelian Genetics
Law of Independence
Law of Segregation
Non-disjunction
Homologous
Genetic variability
Sexual Reproduction
Sex Cells (gametes)
DNA Fingerprinting
Genetic Modifications
Karyotype
Gregor Mendel
Learning Targets:
Assignments
Stock Questions
1. I recognize the significance of
meiosis to reproduction.
Why is it important for the
gametes (sex cells) to divide?
How do Mitosis and Meiosis
Compare? Contrast?
What is the difference between an
inherited and an acquired
characteristic?
2. I can explain the difference
between homozygous and
heterozygous; dominant and
recessive; and phenotype and
genotype.
3. I can predict the possible
outcomes of various genetic
combinations when used in
monohybrid and dihybrid crosses
(Punnett Squares).
4. I can explain what a nondisjunction is and its affects.
What is the only way a recessive
trait can be expressed.
Why is it important for the
homologous chromosomes to
separate during meiosis?
5. I can predict the outcomes of
incomplete dominance, co-dominance
and sex-linked punnett squares.
6. I can describe how gene
technology such as DNA
Fingerprinting, Gene Splicing and
Karyotyping are used to study the
genomes of organisms.
7. I can read and explain how
DNA Fingerprinting
(electrophoresis) works to give
scientists information about an
organism’s genome
8. I can explain how gene
modifications are used to study
and treat genetic disorders.
9. I can explain how gene
modifications are used to study
and treat genetic disorders.
10. I can interpret karyotypes
to identify genetic disorders
Why is DNA Fingerprinting
important to scientists?
How is a DNA Fingerprint
made?
Why is it important that
genes can be manipulated?
Page 2
Level of
Understanding after
discussion and
assignments:  or

Mendel and Genetics Notes:
Gregor Mendel ______________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
GENETICS/HEREDITY/INHERITANCE: ________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
__________________________________________________________
THE PRINCIPLE OF DOMINANCE: ___________________________
_________________________________________________________ Give an example of a dominant trait:
_________________________________________________________
_________________________________________________________
_________________________________________________________ Give an example of a recessive trait:
_________________________________________________________
_________________________________________________________
THE PRINCIPLE OF SEGREGATION: _______________________
_______________________________________________________
_______________________________________________________
Give an example of a gene:
_______________________________________________________
Gene: _________________________________________________
Give an example of an allele:
_______________________________________________________
_______________________________________________________
Give an example of Homozygous:
Allele: _________________________________________________
_______________________________________________________
Give an example of Heterozygous:
Homozygous: __________________________________________
Heterozygous: _________________________________________
Give an example of Genotype:
Genotype: _____________________________________________
Phenotype: ____________________________________________
Page 3
Give an example of Phenotype:
Mendel and Genetics Notes Continued…………..
PRINCIPLE OF PROBABILITY: ___________________________
______________________________________________________
______________________________________________________
In your own words, what does
probability mean?
________________________________
________________________________
PUNNETT SQUARES: ___________________________________
Punnett Square (or Monohybrid Cross)
_______________________________________________________
Cross: _______ X ________
_______________________________________________________
PRACTICE PROBLEMS:
Cross a Heterozygous Tall (T) Pea Plant with a homozygous
small (t) Pea Plant. Show all your work!
Cross a Homozygous Green (G) plant with a yellow (g) plant.
DIHYBRID CROSS: _____________________________________
Genotype %: _____________________
______________________________________________________
Phenotype %: ____________________
______________________________________________________
Cross: ______ X ______
Genotype %: _____________________
Phenotype %: ____________________
PRINCIPLE OF INDEPENDENT ASSORTMENT: _______________
________________________________________________________
________________________________________________________
________________________________________________________
Page 4
SHOULD THIS DOG BE CALLED SPOT?
Imagine this microscopic drama. A sperm cell from a male dog fuses with an egg cell from a female dog. Each
dog’s gamete carries 39 chromosomes. The zygote that results from the fusion of the gametes contains 78
chromosomes – one set of 39 chromosomes from each parent. One pair of the zygote’s chromosomes is shown
below.
Chromosome from the female dog
L
T
T
A
h
Chromosome from the male dog
l
T
l
H
a
a
Each chromosome of the homologous pair contains alleles for the same traits. But one chromosome may have a
dominant allele and the other may have a recessive allele. Use the drawing above and the table below to answer
the questions.
TRAIT
Hair length
Hair Texture
Hair Curliness
Coat Pattern
1.
Dominant Gene
Short (L)
Wiry (T)
Curly (H)
Spotted (A)
Recessive Gene
Long ( l )
Silky ( l )
Straight ( h )
Solid ( a )
Will the new puppy have a spotted coat? _________
Explain why or why not: ______________________________________________________________
__________________________________________________________________________________
2. Does the female dog (mother) have a spotted coat? ______
Explain how you know this: ____________________________________________________________
____________________________________________________________________________________
3. Does the male dog (dad) have a spotted coat? _______
Explain how you know this: _____________________________________________________________
____________________________________________________________________________________
Page 5
4.
What will be the texture of the puppy’s coat? ________________________________________
5.
Will the texture of the puppy’s coat resemble that of either of its parents? ___________
Explain how you know this: _______________________________________________________
______________________________________________________________________________
______________________________________________________________________________
6.
Will the puppy have curly hair or straight hair? ________________________________________
7.
a. Does the female dog have curly hair? ____________________________________________
b. Does the male dog have curly hair? _____________________________________________
8.
a. Define the term heterozygous: ________________________________________________
__________________________________________________________________________
b. For which traits is the puppy heterozygous? _____________________________________
__________________________________________________________________________
9.
a. Define the term homozygous ______________________________________________________
________________________________________________________________________________
b. For which traits is the puppy homozygous? __________________________________________
________________________________________________________________________________
10. Explain why you cannot completely describe the puppy’s parents even though you can accurately describe
the puppy. ___________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
Page 6
Dragons are a curious type of creature. Amazingly, though, their genetics is very similar to that of humans.
Hagrid, the Gamekeeper at Hogwarts, wishes to develop a herd of dragons for his Care of Magical Creatures class.
Unfortunately, he only has two dragons as of now. The purpose of this activity is to determine what kinds of dragons
Hagrid will have in his herd when (and if) his two dragons decide to mate. Interestingly, dragons make good tools for
the investigation of genetics and meiosis
My Baby Dragon’s
Genotypes and Phenotypes
Trait
Genotype
(Symbols for
Alleles)
Neck size
Body color
Spikes? (on end of
tail or not on end
of tail)
Eye color
Number of toes
Horn? (present or
absent)
Fire breathing?
Belly color
Color of spikes
Freckles?
Tail length
Color of wings
Gender
Ear frills present or
absent?
Page 7
Phenotype
(Appearance)
MY BABY’S FIRST PICTURE
Page 8
WHEN IN DOUBT PUNNETT!!
BIOLOGY 1
In rabbits, the gene for black (B) fur is dominant over the gene for white fur (b). Write the genotype and phenotype
for the following table.
GENOTYPE
PHENOTYPE
Heterozygous
Homozygous Dominant
Homozygous Recessive
1.
The pair of letters that represent the genes of an organism is called the __________.
2.
The description of the trait by gene expression (such as black fur or white fur) is called the ______________.
3. A capital letter (B) represents the gene as ____________________________________________.
4. A lower case letter (b) represents the gene as ________________________________________.
5. Genes that are alike in an organism are called _______________________________________.
6. Genes that are different in an organism is called _____________________________________.
Circle the correct answer:
7.
Bb is (circle one) : homozygous or heterozygous?
8.
BB is (circle one): homozygous or heterozygous?
9.
bb is (circle one): homozygous or heterozygous?
10.
B is (circle one): dominant or recessive?
11.
b is (circle one): dominant or recessive?
12.
Bb is the genotype or phenotype?
13.
Black is the genotype or phenotype?
14.
White is a genotype or phenotype?
15.
BB is a genotype or a phenotype?
16.
bb is a genotype or a phenotype?
Page 9
DIRECTIONS: Work the following problems using the Punnett squares provided below and be sure to show ALL your work to
include the genotype and phenotype results.
18.
Cross a homozygous tall (A) plant
homozygous short ( a ) plant.
19.
Cross: ____________ X ______________
Cross a heterozygous blue (B) plant with a
homozygous red (b) plant.
Cross: ____________ X __________
Genotype %: ________
Genotype %: _______
Phenotype %: ________
Phenotype %: ______
_
20.
Cross two heterozygous smooth (H)
plants (h will be rough)
21.
Cross: __________ X ___________
22.
Cross a homozygous Blue plant with leaved
a heterozygous Blue plant.
Cross: __________ X __________
Genotype % _____
Genotype %
Phenotype % _____
Phenotype % _____
Cross a heterozygous yellow (G)
seeded plant with a green (g)
seeded plant.
23.
Cross: _______ X _________
Cross a homozygous smooth leaved
plant (M) with a rough (m) leaved plant.
Cross: _________ X _________
Genotype % ______
Genotype % _______
Phenotype % ______
Phenotype % ______
Page 10
MORE PUNNETT PRACTICE !!!!!!
Here are some more Punnett Squares for practice. Remember your definitions for the following problems:
_____ 1.
Genes of an organism that are alike
a.
Dominant
_____ 2.
Covers a weaker gene
b.
Recessive
_____ 3.
An organism that has different genes
c.
Genotype
_____ 4.
The actual genetic make-up of an organism
d.
Phenotype
_____ 5.
The physical appearance of an organism
e.
Homozygous
_____ 6.
A weaker gene that can be covered.
F.
Heterozygous
Punnett Practice: Assign capital letter G to be the DOMINANT gene and lowercase g as the
recessive gene for every punnett square.
REMEMBER: GG OR gg is Homozygous and Gg is Heterozygous. G is dominant and g is
recessive.
Green hair is DOMINANT over gold hair
G
will represent the dominant gene
g will represent the recessive gene
1.
Homozygous Dominant X Homozygous Dominant: _____________X___________
Genotype %: ________________
Phenotype %: _______________
Page 11
2.
Homozygous Dominant X Homozygous Recessive: _________ X _________
Genotype %: ________________
Phenotype %: _______________
3.
Heterozygous X Heterozygous: ___________ X ____________
Genotype %: ________________
Phenotype %: _______________
4.
Heterozygous X Homozygous Recessive: ___________ X __________
Genotype %: ________________
Phenotype %: _______________
5.
Homozygous Recessive X Homozygous Recessive: __________ X __________
Genotype %: ________________
Phenotype %: _______________
Page 12
Use the chart to identify the genotypes of the following traits and to solve the following problem:
Trait
Body Shape
Body Color
Eye Shape
Nose Style
Dominant gene
Squarepants (A)
Yellow (B)
Round ( R)
Long (L)
Recessive Gene
Roundpants (a)
Blue (b)
Oval (r)
Stubby (l)
6. Heterozygous round eyes, blue body _____________________________
7. Hybrid (Heterozygous) eye shape, purebred (Homozygous) roundpants __________________________
8. Purebred (Homozygous) roundpants, Hybrid (heterozygous) long nose _____________________
SpongeBob’s Aunt Betty, who is a roundpants, has a cute, stubby nose. She has finally found the sponge
of her dreams and is ready to settle down. Her new boyfriend, Tommy, always comments on how adorable
her nose is (he says it reminds him of his mother’s – awwww isn’t that sweet?) They wonder what the
chances are that their children would have a stubby nose like Betty. Tommy is a purebred squarepants
but is a hybrid for a long nose.
9.
What is the genotype of Aunt Betty and Tommy? __________ x _________
Aunt Betty = roundpants, stubby nose
Tommy = Purebred Squarepants, long nose
Genotype ratio: ______________________________
___________________________________________
Phenotype ratio: _____________________________
____________________________________________
Page 13
Using the dihybrid cross to the right, answer the following questions:
1. What is the cross for this dihybrid?
___________ x ____________
2. What are the chances of offspring being heterozygous
for both traits? _________
3. What are the chances of offspring being homozygous
for long tails? __________
4. What are the chances of the offspring being
homozygous for being submissive and
defeated? ____________
5. What are the chances of the offspring being without
tails? ___________
6. What is the genotypic ratio of this dihybrid?
__________________________________
7. What is the phenotypic ratio of this dihybrid?
_____________________________________
Using the diagram to the right, answer the following
questions:
1. What 2 traits do you think are being crossed?
________________________________________
________________________________________
2. What is the genotypic ratio illustrated in this dihybrid
cross? ____________________________________
__________________________________________
__________________________________________
3. What is the phenotypic ratio illustrated in this dihybid
cross? ____________________________________
__________________________________________
_________________________________________
Page 14
OTHER PATTERNS OF INHERITANCE OF GENES
LAW OF INDEPENDENT ASSORTMENT states __________________________________________________________
_________________________________________________________________________________________________
Sex-Linked Traits: A trait that is determined by a gene on a _________ chromosome (usually the ___ chromosome).
Examples of Sex Linked Traits: ______________________, __________________ & __________________________
Females must receive __________________________ in order to express the trait. Females with 1 affected X are called
__________________. Males that receive _____________ from their mother expresses the trait.
Practice: Cross a colorblind mother with a father who has normal vision. Give the expected phenotypic and genotypic
ratios of the offspring.
Key: _____________________________________________ Cross: __________ x __________
Genotypic Ratio: _________________________________
Phenotypic Ratio: ________________________________
Polygenetic Traits

“___________________”; Many __________ are controlled by more than one gene; have a _____________________ for
________________. Example: _______________________________________
Multiple Allele

Genes that have more than ____ alleles. For example: ________________ - there are _____ possible alleles for this
gene.
Practice: Cross a female who has Type A blood (AA) with a male who has Type O Blood (ii)
Key: _____________________________________________ Cross: ____________ X ______________
Genotypic Ratio: ______________________
Phenotypic Ratio: _____________________
Page 15

INCOMPLETE DOMINANCE
Neither allele has “______________” dominance over the other; _______________________________ is a _________
of the 2 homozygous phenotypes

Ex: ____________________
R = red
W = white
RW = _________
Practice: Cross a red (R) snapdragon with a White (W) snapdragon. Give the genotypic and phenotypic ratios.
Key: R = red flower W = white flower
Cross: RR x WW
Genotypic Ratio: __________________________________
Phenotypic Ratio: _________________________________
Practice: Cross a pink snapdragon with a red snapdragon. Give the expected phenotypic and genotypic ratios.
Key: __________________________
Cross: _________________________
Genotypic Ratio: __________________________________
Phenotypic Ratio: _________________________________

CODOMINANCE
Both alleles _____________ dominance and are always _______________ if present. Ex: _______________________
B = black feathers
W = white feathers
BW = ____________________ feathers
Practice: Cross a black (B) chicken with a white (W) chicken. Give the genotypic and phenotypic ratios.
Key: BB = black feathers WW= white feathers Cross: BB x WW
Genotypic Ratio: __________________________________
Phenotypic Ratio: _________________________________
Practice: Cross two black and white feathered chickens. Give the expected phenotypic and genotypic ratios of the
offspring.
Key: ___________________________________
Cross: _______________________
Genotypic Ratio: __________________________________
Phenotypic Ratio: _________________________________
Page 16
PRACTICE WORKSHEET FOR OTHER PATTERNS OF INHERITANCE:
SEX-LINKED PUNNETT SQUARES:
CROSS: A man with normal vision marries and has children with a woman who is a carrier of
the colorblindness allele. What percentage of their offspring would be colorblind?
CROSS: ___________________ X ____________________
Genotype %: ________________________________________
Phenotype %: _______________________________________
CROSS: A normal blooded male marries and has children with a woman who is a carrier of the
hemophilia allele. What percentage of their offspring will have hemophilia?
CROSS: ___________________ x _________________________
Genotype %: ___________________________________________________
Phenotype %: __________________________________________________
CROSS: A colorblind male marries and has children with a woman who is a carrier of the
colorblind allele. What percentage of their offspring will be carriers?
CROSS: ___________________ x _________________________
Genotype %: __________________________________________
Phenotype %: __________________________________________
Page 17
INCOMPLETE DOMINANCE PUNNETT SQUARES:
CROSS: In Andalusian fowls, Black individuals (B) and White individuals (W) are homozygous.
Fill in the blanks below and do the punnett square. Be sure to show all of your work.
A homozygous black bird is crossed with a homozygous white bird. The offspring produced are bluish-gray.
Genotypes:
Black bird = _______
White bird = ______
Offspring = _______
CROSS: What results if a black fowl is crossed with a bluish-gray fowl? Show all your work.
Cross: _______ x _________
Genotype %: ______________________________________
Phenotype %: ______________________________________
SpongeBob and his pal Patrick love to go jellyfishing at Jellyfish Field. The fields are home to a special
type of green jellyfish known as Goobers and only really great fishermen are lucky enough to catch some
on every trip. Many of the jellyfish are yellow (YY) or Blue (BB) but some end up green.
What would happen if SpongeBob and Patrick crossed two Goobers?
Cross: _______ x ________
What % offspring would be yellow? ______
What % offspring would be blue? _______
What % offspring would be Goobers? ________
CO-DOMINANCE PUNNETT SQUARES:
Brad Pitt is homozygous Type B blood while Angelina Jolie is Type o blood. What are the possible
genotype and phenotype % of their offspring?
Cross: ________ x ________
Genotype %: _____________________________
Phenotype %: ___________________________________________________
Page 18
MEIOSIS (CELL DIVISION OF GAMETES)
MEIOSIS: _______________________________________________________________________
_________________________________________________________________________________
Meiosis only occurs in ______________________________________________________________
What are homologous chromosomes? ______________________________________
________________________________________________________________________________
What is a Diploid Cell? __________________________________________________
_____________________________________________________________________
What is a Haploid Cell? __________________________________________________
________________________________________________________________________________
2 Distinct Divisions of Meiosis: ___________________________________________________
________________________________________________________________________________
________________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_______________
Page 19
Each chromosome pairs with its ______________________________ homologous chromosome to
form a structure called a _______________________. There are 4 ______________________ in
a tetrad.
As homologous chromosomes pair up, they exchange ______________________ information in a
process called _____________________________ over producing new combinations of alleles
which account for ___________________________________ among species.
Gamete Formation in Meosis:
HUMAN SPERM + HUMAN EGG = FERTILIZTION WHICH RESULTS IN HUMAN ____________.
Type of Cells
Examples of Cells
Number of
Chromosomes
Where in body found?
# of times goes through
Cytokinesis
MITOSIS
Somatic
Skin, Blood, Heart
(2n)
All over the body
Once
MITOSIS VS. MEIOSIS:
Page 20
MEIOSIS
BIOTECHNOLOGY
What is Biotechnology? the use of living systems and organisms to
___________________ or _______________________________. It can
also be any technological application such as ________________,
___________________________________ (DNA fingerprinting) and
___________________ that uses biological systems and living organisms to
___________ or _____________ products or processes for specific use.
•
Artificial Selection: Earliest form of biotechnology that has been used in
________________ and _______________. Its purpose is to produce
_____________________ traits. There are 2 types of artificial selection:
1. ____________________
2. ____________________(aka hybridization)
•
Inbreeding: Crossing 2 organisms with ________________________.
Purpose: __________________ desirable traits in the same line of
organisms
Risks: Can cause ________________ _____________ (rr) traits to be
expressed such as deafness, blindness, joint deformations.
•
Outbreeding: Crossing 2 organisms from ___________________ species
(genotypes). This is also known as “____________________”. It
____________ causes _______________ but can also be used to
conserve ___________________________ species and increase
_________________ and _____________ in plants and animals.
Page 21
•
Genetic Engineering: Technique(s) used to _______________ or
_____________________ genes at the molecular level.
•
Many uses such as: determining ___________________, identifying a
__________________ of a particular ____________ for a particular disorder,
etc. One technique is _______________________________ used to make a
pattern called a “DNA Fingerprint”.
•
DNA Fingerprinting: an __________________ of ______________ of
_____ that have little or no known function in order to identify one individual
from another.
•
Cloning:
A process used to ________________ an organism that is an
_________________________________________ of another. This means
that every single bit of DNA is the same between the two (like identical twins).
•
Genetically Modified Foods: Also known as __________________ Plants,
food that have been genetically engineered for many reasons such as faster
_____________, _____________________ to pathogen and production of
extra ____________________.
•
Gene Splicing: A process used to take ________________ genes from one
organism and _____________ them into another organism.
Page 22
DNA Fingerprinting
http://www.pbs.org/wgbh/nova/education/body/create-dna-fingerprint.html
What item was disturbed in Jimmy’s room? _________________________________________________________________
What DNA evidence was left behind at the crime scene to test?
___________________________________________________
What is electrophoresis?
________________________________________________________________________________________
_______________________________________________________________________________________
What charge does DNA have?_____________________ What charge is it attracted to?_________________
What size fragment moves easily through the agarose gel? ____________________
By moving the DNA band over the suspects, determine who committed the crime. ____________________
In what ways is it like actual fingerprinting and in what ways is it different? _________________________
_________________________________________________________________________________________
_______________________________________________________________________________________
Cloning an Organism
htpp://learn.genetics.utah.edu/content/tech/cloning/clickandclone/
The Cloning of Mimi the mouse:
Step 1: The somatic cell is a ______________ cell and are found in the layer of cells around the ____________ cell.
Step 2: Removing the nucleus from the egg cell the egg is now an _______________________egg cell.
Step 3: We will transfer the __________________cell nucleus into the ____________________egg cell.
Step 4: Here you will begin simulated cell division also known as ________________________________________.
Step 5: Cell division takes place here creating a ball of cells called a __________________. The embryo continues to
increase in cell number and form various ___________________. A mouse pregnancy lasts __________ days.
Step 6: You have created a ______________of Mimi and the pup’s color is ____________. Why? __________________
__________________________________________________________________________________________
Page 23
GENE TECHNOLOGY WORKSHEET:
Build a corn plant gene that is resistant to insects.
Corn
Spliced Gene
Corn
Build a strawberry gene that is resistant to freezing temperatures.
Strawberry
Spliced Gene
Strawberry
A farmer decides to grow roses WITHOUT thorns. Create a thornless rose.
Cut along this dotted line
Create a new gene segment by cutting the organism DNA and gluing in the new gene.
Organism
Genes
Corn: Color Yellow
Insect Resistance
Strawberry: Color Red
Cold Resistance
T
Rose: Color Green
Page 24
SELF QUIZ
1.
Which of the following accurately identifies all the possible combinations of genes in the
offspring of two parents who are heterozygous for the gene with a dominant form (R) and a
recessive form (r).
A.
B.
C.
D.
2.
The process of DNA fingerprinting allows scientists to study organisms by doing which of the
following?
A.
B.
C.
D.
3.
Ty, ty
TY, ty
TY, Ty, ty
Ty, ty, tY, TY
Which statement below best describes genetic modification?
A.
B.
C.
D.
6
It produces haploid gametes, with half the number of chromosomes.
It creates organisms with better adaptability to the environment.
It allows all types of cells to produce two sets of identical chromosomes.
It produces up to eight haploid cells, each with 46 chromosomes.
If a corn plant has a genotype of Ttyy, what are the possible genetic combinations that could
result in a single grain of pollen from this plant?
A.
B.
C.
D.
5.
Analyzing DNA left behind in the oily residue of fingerprints
Making images of sequences of DNA from individual organisms
Breaking open an individual's cells to release the DNA fragments
Matching of base sequences in the DNA sample with that of finger cells
Which statement best describes the significance of meiosis to sexual reproduction?
A.
B.
C.
D.
4.
rr only
RR only
Rr and rr only
RR, Rr, and rr only
It is a method of identifying proteins of particular DNA sequences.
It is the replacement of a set of chromosomes of an individual with another.
It is a technique used to compare DNA sequences of one individual to another.
It is the insertion of a gene from one organism into a host genome.
In fruit flies, the gene for eye color is located on the X chromosome, and the red eye allele (R) is
dominant over the white eye allele (r). A female fly with genotype XRXr is mated with a male fly
with genotype XrY. Which statement below best describes the expected outcome of this cross?
A.
B.
C.
D.
XrY = 0%
XRY = 25%
XrXr = 50%
XRXR = 100%
Page 25
7.
In certain rose plants, white roses (W) and red roses (R) are incompletely dominant to one
another. When a red rose is crossed with a white rose, a pink rose(RW) will result. What is the
probability of producing more pink roses from two pink parents?
A.
B.
C.
D.
8.
The gene for tallness (T) in a pea plant is dominant over the gene for shortness (t). The Punnett
square below shows the cross between two tall pea plants (Tt). What is the phenotypic ratio of
the offspring produced as a result of the cross?
A.
B.
C.
D.
9.
DNA fingerprinting
Gel electrophoresis
Karyotyping
Genetic modification
During meiosis, genetic recombination results because –
A.
B.
C.
D.
11.
1:2:1
9:3:3:1
3:1
2:1
Nondisjunction is an error that occurs during meiosis when a gamete does not receive a copy of
one chromosome. Which technique can be used to reveal this abnormality?
A.
B.
C.
D.
10.
0%
25%
50%
100%
chromosomes assort independently, and crossing-over occurs
genes from different species can freely mix together
gene mutations occur more frequently than at other times
cells divide only once, resulting in genetically identical cells
What is the probability that a yellow (Y) and wrinkled pea (r) will appear from a cross of
Yyrr x YyRr?
A.
B.
C.
D.
3/8
1/2
3/4
7/8
Page 26