Mendel &
Heredity
Ch. 6.3
Gregor Mendel
 Mid-1800’s he explained how traits
are inherited from parents and
passed to offspring
 Every organism inherits their specific
traits (AKA genes)
 One from Mom and one from Dad
 Mendel made this discovery by
breeding peas
Mendel’s Pea Plant Experiments
1. Controlled the breeding
2. Used purebred plants
3. Observed “either-or” traits that appeared in
only two alternate forms
 Why were these factors important for his
experiment?
Traits Observed
How did Mendel discover
dominant/recessive traits?
Punnett Squares!
http://www.siskiyous.edu/class/bio1/genetics/monohybrid_v2.html
Mendel’s Conclusions
 1.) Traits are inherited as discrete units
 2.) Organisms inherit two copies of each gene,
one from each parent
 3.) Organisms donate only one copy of each
gene in their gametes. Thus the two copies of
each gene segregate, or separate, during
gamete formation
 (#2 & 3 = Law of segregation)
Traits Observed
Vocabulary
1.
Genetics
10. Homozygous
2.
Gene
11. Heterozygous
3.
Allele
12. Purebred
4.
Law of Segregation
13. Dominant
5.
Law of Independent
Assortment
14. Recessive
6.
Punnett Square
7.
Probability
8.
Monohybrid Cross
9.
Dihybrid Cross
15. Phenotype
16. Genotype
17. Incomplete Dominance
18. Codominance
19. Polygenetic Inheritance
20. Sex-Linked
Complex Patterns
of Inheritance
Ch. 7.2
Incomplete Dominance
 = where heterozygous phenotype is somewhere
between two homozygous types.
 AKA= Blending of traits
 Ex: colors of certain flowers where:
 RR= red
Rr= pink
rr=white
 Neither allele is completely dominant or
recessive!
Codominance
 = where both alleles of a gene are
expressed completely
 Both traits are fully and separately
shown
 Ex: blood types where a person can
have-
 A, B, AB, or O
Blood Types
 We always use the letter “I” AND superscript to
show blood genotypes
 IA and IB are codominant and i is recessive
Blood Types
 So what does this mean for blood donations and
transfusions?
Blood Types
 So what does this mean for blood donations and
transfusions?
 Antigens are proteins on the blood that prevent
transfusions from foreign blood types
 A= can only get blood from IAIA or ii
 B= can only get blood from IB IB or ii
 AB= can donate to IAIA or IB IB or IA IB, but can only
receive from IA IB or ii
 O= is a universal donor, but can only accept
transfusions from ii
Polygenetics
 = traits produced by two or more genes
 Ex: human skin color (produces a range or
spectrum of colors)
 What’s another example?
Epistasis
 Epistatic genes= can interfere with the expression
of other genes
 Mice and other mammals have 5 genes to
determine color (making them polygenetic)
 The 5th gene can overshadow all other genes
 Ex: Albinism
Dihybrid crosses
 =crosses that look at
inheritance of two different
traits.
 Ex: peas that are
yellow/green with
smooth/wrinkled skin
Exit Slip
 A man with homozygous type A blood and a
woman with heterozygous type B blood want to
know the probability of having a child with type
AB blood.
 Draw a Punnett Square and write a percentage.
Genetics Disorder Brochure
Project
 Create a tri-fold brochure
 Needs to be creative and informative
 Research a genetic disorder
 ANSWER ALL QUESTIONS!!
 Include work cited/reference page
List of Genetic Diseases
 Adrenoleukodytrophy
 Patau Syndrome
 Angleman Syndrome
Duchenne Muscular
Dystrophy
Edwards Syndrome
Fabry Disase
Hemophilia A/B
Huntington’s Disease
 Burkitt’s Lymphoma
 Jacobson Syndrome  Rett Syndrome
 Cat Eye Syndrome
 Marfan Syndrome
 Sickle Cell Anemia
 Cri-du-chat (Cat’s Cry Syn.)
 Monsomy 9p (Alfi’s
 Smith-Magenis
 Mytonic Dystrophy
 Von Hippel-Lindau
 Albinism, oculocutaneous
 Alzheimer Disease, familial
type 5
 Cystic Fibrosis
 DiGeorge Syndrome
 Down’s syndrome
Syndrome)
 Neurofibromatosis
(Trisomy 13)
 PKU
 Prader-Willi Syndrome
 Rentinitis pigmentosa
Syndrome
Syndrome
 Wolf Hirschhorn
Syndrome
Human Genetics &
Pedigrees
Ch. 7.4
Genetic Disorders
 Only females can be carries of sex-linked
genetic disorders
 Brainstorm WHY?
Genetic Disorders
 Only females can be carries of sex-linked
genetic disorders
 Brainstorm WHY?
Genetic Disorders
 The likelihood of inheriting a sex-linked disorder
depends both on the sex of the child and which
parent carries the disorder-causing allele.
 Do you think a boy or girl is more likely to have a
sex-linked disorder if the mother is a carrier?
Genetic Disorders in History
 Queen Victoria of the British royal family was a
carrier for a sex-linked disorder called hemophilia
 Hemophilia= lacks proteins that allows blood to
clot.
 She passed this disease to her son, and he then
passed it to his daughter who was a carrier.
 Because royal families tend to marry into other
royal families, several other countries blood lines
now had hemophilia “The Royal Disease”
Pedigrees
 Pedigree= chart that can help trace the
phenotypes and genotypes in a family
 Helps to determine whether people carry
recessive alleles
 Males= squares
 Females= circles
 Shaded= affected/ shows the trait
 Half-shaded= carrier for the trait
Pedigrees
 The disease can be carried on autosomes or sex
chromosomes
 Autosomal= gives males & females 50% chance of
inheritance
Patterns of Inheritance
1.
Autosomal Dominant
 The inheritance of one mutated copy of a gene results in trait / disease.
 These traits / disorders tend to occur in every generation of an affected
family.
 Examples: Huntington disease, polydactyly
2.
Autosomal Recessive
 The inheritance of two mutated copies of a gene results in disease.
 An individual that inherits a single copy of the mutated gene is known as
a carrier. Both males and females can be carriers.
 Examples: cystic fibrosis, sickle-cell anemia, Tay-Sachs disease
3.
Sex-Linked (X-Linked Recessive)
 The inheritance of a mutated gene on an X chromosome may result in
disease.
 Only females can be carriers, therefore men are more frequently
affected
by these types of disease.
 Examples: colorblindness, hemophilia
Harry is the son of Lily and James Potter. Lily Potter had two
parents and a sister without any magical ability (muggles).
Assuming magical ability is recessive, what are the genotypes
of Harry Potter’s maternal grandparents?
 Construct a Punnett square to justify your answer.
 Describe Harry Potter’s genotype using genetics
vocabulary.
Harry Potter’s maternal grandparents are heterozygous, Mm:
M m
M MM Mm
m Mm mm
Harry Potter, like his mother Lily, is homozygous recessive for
magical ability.
Biotechnology
 Hypothesize what it is?
Biotechnology
 Hypothesize what it is?
 Biotechnology= the use and application of living
things and biological processes
 What are some examples?
Biotechnology
 Hypothesize what it is?
 Biotechnology= the use and application of living
things and biological processes
 What are some examples?
 Microorganisms used to make bread and cheese
 Liquid BandAid used to seal wounds and replicate
skin
 Hybrid fruit trees to create new fruits (Grapple)
Medical Biotechnology
 Work in pairs with your shoulder partner (the person
next to you)
 1 iPad per pair
 Job Roles:
 Reporter- researches information and relays information
to recorder
 Recorder- writes down information on paper
YOU & YOUR PARTNER WILL TURN IN ONE SHEET OF PAPER
WITH ALL THE INFORMATION!
Medical Biotechnology Activity
For your example, answer the following:
1.
What is it?
2.
What can it be used for?
3.
How is biotechnology used in your example/product?
4.
What are the potential impacts to
5.
a)
The individual (aka YOU!)
b)
Society
c)
The environment
Record your findings on paper to be turned in
Cite your sources! You need at least two.
Genetically Modified Foods
 How much genetically modified food accounts
for your daily diet?
 Are genetically engineered foods safe?
Genetically Modified Foods
 What concerns does the video clip address?
 http://www.youtube.com/watch?v=aMfSGt6rHo
s&feature=youtu.be&safe=active
 Do the benefits outweigh the disadvantages?
 http://www.youtube.com/watch?v=4QFhD1E8G
Es&feature=endscreen&safe=active
Biotechnology in Medicine
 Going back to when you researched biotech. In
medicine with your shoulder partner…
 Turn around to the partnership behind you and discuss:
1.
2.
3.
4.

What is it?
What can it be used for?
How is biotechnology used in your example/product?
What are the potential impacts to you, society, &
environment
Be prepared to discuss as a class!
 If the trait for brown eyes (B) is dominant over
blue eyes (b), what would be the probability of a
man who’s heterozygous for the trait and a
woman who’s homozygous recessive for the trait
having a child with blue eyes?
 If the trait for brown eyes (B) is dominant over blue
eyes (b), what would be the probability of a man
who’s heterozygous for the trait and a woman who’s
homozygous recessive for the trait having a child with
blue eyes?
B
b
b
Bb
bb
b
Bb
bb
 Colorblindness is a sex-linked trait caused by a
recessive allele carried on the X chromosome
(Xc). What are the possible phenotypes for the
children of a colorblind father (XcY) and normal
vision mother (XCXC)?
 Colorblindness is a sex-linked trait caused by a
recessive allele carried on the X chromosome
(Xc). What are the possible phenotypes for the
children of a colorblind father (XcY) and normal
vision mother (XCXC)?
Xc
XC
XC
Y
XCXc
XCY
XCXc
XCY
 The probability that two parents who are
heterozygous will have a child with a disorder is
25%. Which of the following best applies to the
inheritance pattern for this disorder?
 The probability that two parents who are
heterozygous will have a child with a disorder is
25%. Which of the following best applies to the
inheritance pattern for this disorder?
RECESSIVE
 List an example of a polygenetic trait in humans
 List an example of a polygenetic trait in humans
Hair color, eye color, height, etc…
 A man with homozygous type A blood and a
woman with heterozygous type B blood want to
know the probability of having a child with type
AB blood.
 A man with homozygous type A blood and a
woman with heterozygous type B blood want to
know the probability of having a child with type
AB blood.
B
O
A
A
AB
AB
AO
AO
 What kind of genotype would the parents have
to be to give you a 9:3:3:1 ratio?
 What kind of genotype would the parents have
to be to give you a 9:3:3:1 ratio?
2 heterozygous parents
 Green seeds (G) are dominant over yellow seeds
(g). What would the genotypes of a cross
between a homozygous dominant and
homozygous recessive plant?
 Green seeds (G) are dominant over yellow seeds
(g). What would the genotypes of a cross
between a homozygous dominant and
homozygous recessive plant?
G
g
g
G
Gg
Gg
Gg
Gg
 If flower color has incomplete dominance,
where RR=red, RW=pink, and WW=white, what
would the results of a RW and RW cross?
 If flower color has incomplete dominance,
where RR=red, RW=pink, and WW=white, what
would the results of a RW and RW cross?
R
W
R
RR
RW
W
RW
WW
 Hemophilia is a sex-linked genetic disease. If a
man with hemophilia and a woman who is a
carrier had children, what is the probability that
their son will have hemophilia?
 Hemophilia is a sex-linked genetic disease. If a
man with hemophilia and a woman who is a
carrier had children, what is the probability that
their son will have hemophilia?
XH
Xh
Xh
XHXh
XhXh
Y
XHY
XhY
 Who is the father of genetics?
 Who is the father of genetics?
Gregor Mendel
 What term would best be used to describe an
organism possessing two identical genes for a
trait?
 What term would best be used to describe an
organism possessing two identical genes for a
trait?
HOMOZYGOUS
 In canaries, the gene for singing (S) is dominant
over the gene for non-singing (s). When hybrid
singing canaries are mated with non-singing
canaries, what percentage of the offspring is
likely to possess the singing trait?
 In canaries, the gene for singing (S) is dominant
over the gene for non-singing (s). When hybrid
singing canaries are mated with non-singing
canaries, what percentage of the offspring is
likely to possess the singing trait?
S
S
s
s
SS
Ss
Ss
Ss