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Genetics (part deux)
name_________________________________________
Patterns of Inheritance
Incomplete Dominance
 A cross between organisms
with _________ different
phenotypes produces offspring
with a ___________
phenotype that is a blending of
the parental traits.
 Blending (mixing)
Ex: Snapdragons
 Punnett
Square
(Incomplete):
If tail length in c ats shows
incomplete dominance, then
LL=long, Ll= medium, and
43. If you cross a short
ll=short.
tailed cat with a medium
tailed cat, what
are the
phenotypic and
genotypic
ratios? Show
the square.
Complete Dominance
Codominance
 The prefix “co” means __________
 A cross between organisms with __________
different phenotypes produces offspring with a
__________ phenotype in which____________
of the parental traits appear _____________.
 YOU SEE BOTH.
 Both alleles contribute to the phenotype of the
heterozygote
 Ex: Blood type
Punnett Square (Codominance): Alice has
type A blood and her husband Mark has type
B blood. Their first child, Amanda, has type
O blood. Their second child, Alex, has type
AB blood. What is Alice’s genotype?______
 What is Mark’s genotype? _____
 What are the
chances they have
a child with AO
blood? Show the
square.
Polygenic Traits.
 Many traits are controlled by ___________
than ___________gene…. not just one.
 Ex: Skin Color
 One trait will completely
cover (mask) the other.
Ex: Mendel’s peas – Purple is
_____________ to white.
Sex Linked Traits
 Traits associated with particular
____________ are called sex-linked or
_____-linked traits.
 Located on the ______ or _____
chromosome.
 Ex: Red-green _________________,
_________________
What is this called?
______________
Is this a boy or a girl?
How do you know?
Linked Genes
 Occurs when particular alleles are
inherited ______________.
 On ____________ chromosome.
 They tend to be inherited together.
 Ex: red hair and freckles.
1st 22 pairs of chromosomes
are called __________________,
the last pair (XY) are __________
chromosomes.
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
explain the role of meiosis in reproductive variability
1
47: Pedigrees: _______ that show relationships within a family.
How many boys? ____________ How many Girls? ____________
How many generations? _______ How many with the disorder? ______
How many marriages are shown? _______
Genetic Disorders to Know
Huntington’s Disease
Colorblindness
 Causes certain
________ cells in
your brain to waste
away
 May experience
uncontrolled
movements, emotional
disturbances and
mental deterioration
 Autosomal or
sexlinked?
 ______________
_____ trait
 Gene for color
vision located on
the X
chromosomes.
 Autosomal or
sexlinked?
 ___________ are
more likely to have
colorblindness.
WHY?
______________
 Fatal? __________
66._____
70. ____
67._____
68.____
69.______
71._____ 72._____________
1. Gamete
Genetics Vocab #2
2. Autosomes
3. Sex Chromosomes
4. Incomplete Dominance
5. Polygenic trait
6. Sex-linked trait
Sickle Cell
Down Syndrome
 Three copies of
chromosome
________.
 Also called
____________
______.
 Caused by
_________________
during meiosis.
Cystic Fibrosis
Hemophilia
 CF is caused by
a __________
allele on
chromosome__.
 Deletion of
three bases.
 Autosomal or
sexlinked?
 Affects the
body's
respiratory and
digestive
systems.
 ______liked Trait
 Located on
the _____
chromosome
 Autosomal
or sexlinked?
 Missing a
protein
necessary for
__________
clotting
 Recessive
allele
 ___________
blood cells
Tay-Sachs
 Harmful
quantities of
________
acids
accumulate in
the nerve cells
 destroys nerve
cells
 fatal
 Practice Problem;
A man and a woman are
both carriers for TaySachs. What is the chance
they will have a child with
Tay-Sachs disease Show
the square.
 Practice Problem;
A man with Huntington’s
(heterozygous) marries a woman
w/out the disease. What are the
chances they will have a child with
the disease? Show the square.
 Practice Problem
 A female whose father is
colorblind marries a male who is
not color blind? Is there a
chance they could have a color
blind child? Show the square.
7. Karyotype
8. Pedigree
9. Linked Genes
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
10. Codominance
explain the role of meiosis in reproductive variability
2
Incomplete Dominance
SpongeBob loves growing flowers for his pal Sandy! Her favorite flowers, Poofkins, are found in red, blue, and
purple. Use the information provided and your knowledge of incomplete dominance to complete each section
below.
1. Write the correct genotype for each color if R represents a red gene and B represents a blue gene.
Red - _____ Blue - ______ Purple - _____
2. What would happen if SpongeBob crossed a Poofkin with red flowers with a Poofkin with blue flowers?
Complete the Punnett square to determine the chances of each flower color.
(a) Give the genotypes and phenotypes for the offspring.
(b) How many of the plants would have red flowers? _____%
(c) How many of the plants would have purple flowers? _____ %
(d) How many of the plants would have blue flowers? _____ %
3. What would happen if SpongeBob crossed two Poofkins with purple flowers? Complete the Punnett square
to show the probability for each flower color.
(a) Give the genotypes and phenotypes for the offspring.
(b) How many of the plants would have red flowers? _____%
(c) How many of the plants would have purple flowers? _____ %
(d) How many of the plants would have blue flowers? _____ %
(e) Why is this incomplete dominance? _____________________________
__________________________________________________________
Codominance
SpongeBob and his pal Patrick love to go jellyfishing at Jellyfish Fields! The fields are home to a special type
of green jellyfish known as Goobers and only really great jellyfishermen are lucky enough to catch some on
every trip. Many of the jellyfish are yellow (YY) or blue (BB), but some end up polka-dotted (called a goober)
as a result of codominance. Use this information to help you complete each section below.
4. Write the correct genotype for each color.
Yellow - _____ Blue - ______ Goober - _____
5. What would happen if SpongeBob and Patrick crossed two “goobers” or polka-dotted jellyfish? Complete
the Punnett square to help you determine the probability for each color of jellyfish.
(a) Give the possible genotypes and phenotypes for the offspring.
(b) What percentage of the offspring would be yellow? _____%
(c) What percentage would be blue? _____ %
(d) What percentage would be “goobers” (polka-dotted)? _____ %
(e) Why is this codominance? __________________________________
________________________________________________________
6. What would happen if they crossed a yellow jellyfish with a goober? Complete the Punnett square to help
you determine the probability for each color of jellyfish.
(a) Give the possible genotypes and phenotypes for the offspring.
(b) What percentage of the offspring would be yellow? _____%
(c) What percentage would be blue? _____ %
(d) What percentage would be “goobers” (polka-dotted)? _____ %
Pedigree Problems
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
explain the role of meiosis in reproductive variability
3
Pedigree #1 shows a family of parrots. One of the offspring shows the trait for
blue feathers. (R = red feathers, r = blue feathers)
1. Do you think blue feathers are dominant or recessive? ______________
2. What must the genotypes of the parents be? _______________
3. What two genotypes could the other offspring have? _______________
Pedigree #2 is studying hair color in a family. In humans, dark hair (B) is dominant
to blonde hair (b). In this case, individuals who are shaded are dark-haired.
Individuals who have clear circles are blonde.
1. What are the genotypes of the parents? _____________________
2. What is the genotype of the sons? _______________________
3. What are the two possible genotypes of the daughters? _____________
Pedigree #3
1. Does the pedigree to the right show that the trait is
autosomal or x-linked? ____________ Explain: _____
_________________________________________
2. Write the genotypes of the affect males (above their
boxes) and their mothers and fathers.
Pedigree #5
Pedigree #3:
STARTER: Determing Genotypes from a Pedigree
#1
a____________ b__________
c____________ d___________
#2
a____________ b___________
c____________
#3
a________________________
b_______, _______, _______
c_______x ______
Review
1. A man that has hemophilia and a woman that is a carrier for hemophilia have a
child. What is the chance that they have a son that has hemophilia? ___________
Show the punnett square.
2. What is nondisjunction? What does it cause? _________________________
_____________________________________________________________
_____________________________________________________________
3. A man that is not colorblind has a child with a woman that is colorblind. What is
the chance that they will have a daughter that is colorblind? Show the punnett
square.
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
explain the role of meiosis in reproductive variability
4
4. List and describe 3 ways that increase genetic diversity in organisms.
1-__________________________________________
2-__________________________________________
3-__________________________________________
5. The pedigree to the right shows the passing on of colorblindness. What sex can ONLY
be carriers of colorblindness? ______ Why? _____
_____________________________________________________
6. Why does individual IV-7 have colorblindness?
_____________________________________________________
7. Why do all the daughters in generation II carry the colorblind gene?
_____________________________________________________
8. MATCHING
_____1. Sickle Cell
_____2. Huntington’s
_____3. Hemophilia
_____4. Colorblindness
_____5. Cystic Fibrosis
_____6. Down Syndrome
_____7. Nondisjunction
A.
B.
C.
D.
Also known as trisomy-21. Occurs when a person has three copies of chromosome #21.
Sex-linked trait where colors are not see correctly.
Process when chromosomes fail to separate during meiosis during gamete formation.
Degenerative disease that causes certain nerve cells in your brain to waste away causing
uncontrolled movements, emotional disturbances and mental deterioration. Fatal.
E. Sex-linked trait where the person is missing a protein necessary for blood clotting- can bleed to
death from a minor cut.
F. Caused by a recessive allele on chromosome #7. Deletion of three bases. Affects the body's
respiratory and digestive systems by causing a build up of mucus.
G. A disease characterized by the bent and twisted shape of the red blood cells. This can cause
weakness and damage to the brain, heart, and spleen- in some cases it can be fatal.
Genetics Web Lab
1. Bitesize; Introduction to Inheritance
(Subtitles really help…turn them on)
1. Different forms of the same gene are called ____________.
2. Alleles are either ________________________ or _____________________________. Which is dominant in eye color?
_______________
3. Rule: _______________________ letter for dominant and a ______________________ case for the recessive.
4. A child gets one ____________________ from each parent.
5. Which pair gives blue eyes? ______
6. What is Huntington’s disease? ____________________________________________________________________
7. Is Huntington’s disease caused by a dominant or recessive allele? __________________
8. What is Cystic Fibroses? _______________________________________________________________________
9. Is Cystic Fibroses caused by a dominant or recessive allele? __________________
10. What is the geneotype of a person with Cystic Fibroses? Click it on the screen: ________
11. If 2 parents are carriers, what is the chance their child will have Cystic Fibroses? Make a Punnett square
12. Chromosome are made of long strands of _____________ that contain ____________________________________.
13. The sex chromosomes determine wheather you are _________________________________________.
14. All eggs from the mother contain a ____ sex chromosome. Sperm can either have _______ or _______ chromosome.
15. ________ is a girl, and _______ is a boy.
2. Learn Genetics: Utah: Sexual Vs. Asexual Reproduction
1. Asexual reproduction generates offspring that are ________________ ________________ to a single parent.
2. Sexual reproduction, two parents __________________genetic information to produce ______________offspring.
3. Choose some organisms on the screen, and try to decide if they reproduce sexually or asexually. List any 2:
a.____________________________________b. ___________________________________
3: Polygenetic Inheritance (video)
1.
AreBiology
all of Standards:
our traits SB2.
controlled
bywill
the
inheritance
of a traits
singleare
gene?
Give
2 successive
examplesgenerations. c. Using Mendel’s laws,
Georgia
Students
analyze
how biological
passed
on to
__________________________________,
explain the role of _______________________________
meiosis in reproductive variability
2. How many genes do they think controls skin color?_______How many genes control eye color?_______
5
4. Click and Clone
1.
2.
3.
4.
∙Follow the steps provided to clone Mimi.
∙Answer the questions below when you are done.
What color was the baby mouse?________________
What instrument did you use to isolate the nucleus?____________________________________
Who was the baby mouse genetically identical to? __________________________________
Do you agree, or disagree, with cloning? Defend your answer in complete, grammatically correct sentences.
5. Pedigree Practice- Interactive (write the answers to each question below)
1-a.________________________b. __________________ c. was it a boy or girl?
2-a. _______________________ b. __________________
3- a. _______________________ b. ______________________________
6. Recessive Autosomal Genetic Disorders Punnett Square
Create the square and answer the questions:
1- If a mother is a carrier for a disease (like Cystic Fibroses) and the father is unaffected, what is the chance they have a child
with cystic fibroses? ______ What were the genotypes of the parents? ______, _______
Click “reset”
2- If Dad is affected and Mom is a Carrier, what are the chances of having a child with the disorder?______
7. Sex Linked Genetic Disorders Punnett Square
READ over the first page and answer these questions:
1- Genes that are found only on the X chromosome are referred to as _____________________________________.
2- At the bottom of the page, what is the chance the 2 parents have a child of NORMAL vision? _______
Click “Next: Sex Linkage Problem
3- Complete the Punnett square showing the possible genotypes of children born to a
colorblind mother and a father with normal vision. MAKE A COPY TO THE RIGHT 
What are the chances of a colorblind male child? ___________
Practice problems:
1. A woman with type AB marries a man with type AB. What are the chances they
have a child with type B (BB or BO) Blood? Show the punnett square.
2. Hemophilia in humans is inherited as an X-linked recessive trait. A woman whose
father is hemophiliac marries a man with normal clotting ability. What is the
probability that her first child will have hemophilia? Assume that the woman's
mother is homozygous dominant. Show the punnett square.
Woman’s genotype? _________ Man’s genotype? ___________
3. In humans, the gene for normal vision (C) is dominant to the gene for color blindness (c). Color
blindness is a sex-linked trait. Which of the following would be the genotype for a colorblind male?
A. XCY
B. XcY
C. XCXc
D. XcXc
4)A woman with red-green color-blindness has a mother with normal vision. Knowing that color-blindness is a
sex-linked recessive gene, can you determine what her father's phenotype is? If so, what is it?_______
5) What happens during meiosis that creates “genetic variability” in sexually reproducing organisms?
a. movement of chromosomes, & separation of sister chromitid
b. separation of sister chromatid, & spindle fiber movement
c. sister chromitids don’t separate, & spindle fibers remove genes
d. crossing over, & independent assortment
6) What is Sickle Cell Anemia? What causes it? (include a picture)__________________________
____________________________________________________________________________
____________________________________________________________________________
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
explain the role of meiosis in reproductive variability
6
7) The process of meiosis produces gametes. How does this process increase reproductive variability?
a. Different combinations of alleles are produced.
b. Each allele from the parent cell forms a separate gamete.
c. Each pair of genes undergoes crossing-over with different genes.
d. The two genes are passed on to a daughter cell, resulting in new traits.
8) A black-feathered chicken and a white feathered chicken are crossed by a farmer. All of the offspring chickens have both black
and white feathers. Which of the following does this exemplify?
A. genetic mutation B. codominant alleles C. dominant alleles D. multiple alleles
9) When a human egg is fertilized by a sperm, the zygote formed is a
A. polyploid cell.
B. triploid cell.
C. diploid cell.
D. haploid cell.
10) A mutation in the gene responsible for producing hemoglobin in the blood causes a disease known as sickle-cell anemia. The parents of
children born with sickle-cell anemia usually have no symptoms of the disease, but tests indicate that both parents are carriers of the
mutated gene. What is the best explanation for these circumstances?
A. The gene for sickle-cell anemia is dominant, and both parents are homozygous.
B. The gene for sickle-cell anemia is dominant, and both parents are heterozygous.
C. The gene for sickle-cell anemia is recessive, and both parents are homozygous.
D. The gene for sickle-cell anemia is recessive, and both parents are heterozygous.
11) The cells of a dog’s tail contain 78 chromosomes. The spermatozoa of a dog contain
A. 39 chromosomes. B. 78 chromosomes. C. 117 chromosomes. D. 156 chromosomes.
12) A researcher crosses the F1 generation of two snapdragon plants. According to this
information, what is the ratio of their offspring (F2)?
A. 2 red: 1 pink: 1 white
B. 0 red: 4 pink: 0 white
C. 1 red: 2 pink: 1 white
D. 1 red: 1 pink: 2 white
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
explain the role of meiosis in reproductive variability
7