Chapter 3 Genetics: Chapter 3 Genetics:
The Science of The Science of
HeredityHeredity
Section 1: Mendel’s WorkSection 1: Mendel’s Work
Section 1- Objectives:Section 1- Objectives:
To describe Mendel’s genetics To describe Mendel’s genetics
experimentsexperiments
To identify the factors that control the To identify the factors that control the
inheritance of traits in organismsinheritance of traits in organisms
To explain how geneticists use symbols To explain how geneticists use symbols
to represent alleles.to represent alleles.
VocabularyVocabulary
1. trait1. trait
A characteristic that an organism can A characteristic that an organism can
pass on to its offspring through its pass on to its offspring through its
genes.genes.
2. 2. heredityheredity
The passing of traits from parents to The passing of traits from parents to
offspring. offspring.
3. 3. geneticsgenetics
The scientific study of heredity.The scientific study of heredity.
4. 4. purebredpurebred
An organism that always produces An organism that always produces
offspring with the same form of a trait offspring with the same form of a trait
as the parent. as the parent.
5. 5. genegene
A segment of DNA on a chromosome A segment of DNA on a chromosome
that codes for a specific trait.that codes for a specific trait.
6. 6. allelesalleles
The different forms of a gene. The different forms of a gene.
7. 7. dominant alleledominant allele
An allele whose trait always shows up in An allele whose trait always shows up in
the organism when the allele is present.the organism when the allele is present.
8. 8. recessive allelerecessive allele
An allele that is masked when a An allele that is masked when a
dominant allele is present.dominant allele is present.
9. 9. hybridhybrid
An organism that has two different An organism that has two different
alleles for a trait; an organism that is alleles for a trait; an organism that is
heterozygous for a particular trait.heterozygous for a particular trait.
10. _______________________ is 10. _______________________ is
called the “father of genetics”called the “father of genetics”
Gregor Mendel
11. Mendel used peas because:11. Mendel used peas because:
–A. _________________________A. _________________________
–B. _________________________B. _________________________
They have many traits that exist in only 2 forms
Garden peas produce large numbers of
offspring in one generation so it is easy
to collect large amounts of data to analyze
12. Traits are controlled by 12. Traits are controlled by
_________________ of _________________ of
__________________________
inheritance
genes
14. Organisms inherit ______ allele 14. Organisms inherit ______ allele
from _________ parent.from _________ parent.
one
each
15. Some alleles are 15. Some alleles are
____________________and others are____________________and others are
__________________________.__________________________.
dominant
recessive
Chapter 3 Genetics: Chapter 3 Genetics:
The Science of The Science of
HeredityHeredity
Section 2: Probability & Section 2: Probability &
GeneticsGenetics
Section 2 -Objectives:Section 2 -Objectives:
To describe the principles of probability To describe the principles of probability
and how Mendel applied them to and how Mendel applied them to
inheritanceinheritance
To state how geneticists use Punnett To state how geneticists use Punnett
squaressquares
To explain the meaning of the terms To explain the meaning of the terms
phenotype, genotype, homozygous, phenotype, genotype, homozygous,
heterozygous, and codominance.heterozygous, and codominance.
10. 10. probabilityprobability
The likelihood that a particular event The likelihood that a particular event
will occur. will occur.
11. 11. Punnett squarePunnett square
A chart that shows all the possible A chart that shows all the possible
combinations of alleles that can result combinations of alleles that can result
from a genetic cross. from a genetic cross.
12. 12. phenotypephenotype
An organism’s physical appearance, or An organism’s physical appearance, or
visible traits. visible traits.
13. 13. genotypegenotype
An organism’s genetic makeup, or allele An organism’s genetic makeup, or allele
combinations. combinations.
14. 14. homozygoushomozygous
Having two identical alleles for a trait.Having two identical alleles for a trait.
15. 15. heterozygousheterozygous
Having two different alleles for a trait. Having two different alleles for a trait.
16. 16. codominancecodominance
A condition in which neither of two A condition in which neither of two
alleles of a gene is dominant or alleles of a gene is dominant or
recessive.recessive.
NotesNotes
1. Probability is the 1. Probability is the
___________________ that a ___________________ that a
____________________ will occur.____________________ will occur.
likelihood
particular event
2. _____________________ was the 2. _____________________ was the
first scientist to recognize that the first scientist to recognize that the
________________________ of ________________________ of
________________________ can be ________________________ can be
used to predict the result of genetic used to predict the result of genetic
crosses.crosses.
Mendel
principles
probability
3. Geneticists use Punnett squares to:3. Geneticists use Punnett squares to:
–A.A.
–B.B.
Show all the possible outcomes of a
genetic cross
Determine the probability of a particular
outcome
4. _________________________ is 4. _________________________ is
the physical appearance, while the physical appearance, while
________________________ is the ________________________ is the
_______________________ make-up._______________________ make-up.
Phenotype
genotype
Genetic makeup
5. Punnett Square 5. Punnett Square
practice:practice:
B-BlueB-Blue
b-redb-red
Genotype: Genotype:
Phenotype:Phenotype:
B b
B
b
BB Bb
Bb bb
1 BB: 2Bb: 1bb
3 Blue, 1 red
5. Punnett Square 5. Punnett Square
practice:practice:
G- GreenG- Green
g-Yellowg-Yellow
Genotype:Genotype:
Phenotype:Phenotype:
G g
g
g
Gg gg
Gg gg
–2 Gg: 2gg
–2 Green: 2 Yellow
Your turn. Practice sheet.Your turn. Practice sheet.
Independent and SilentIndependent and Silent
Refer to your notes.Refer to your notes.
Go over as a group.Go over as a group.
Chapter 3 Genetics: Chapter 3 Genetics:
The Science of The Science of
HeredityHeredity
Section 3: The Cell and Section 3: The Cell and
InheritanceInheritance
Section 3: The Cell and Section 3: The Cell and
InheritanceInheritance
To describe the role of chromosomes in To describe the role of chromosomes in
inheritanceinheritance
To identify and describe the events To identify and describe the events
that occur during meiosisthat occur during meiosis
17. 17. meiosismeiosis
The process that occurs in sex cells The process that occurs in sex cells
(sperm and egg) by which the number of (sperm and egg) by which the number of
chromosomes is reduced by half.chromosomes is reduced by half.
NotesNotes
1. Sex cells have exactly 1. Sex cells have exactly
____________ the number of ____________ the number of
chromosomes as ____________ cells.chromosomes as ____________ cells.
half
other
2. The chromosome theory of inheritance 2. The chromosome theory of inheritance
states:states:
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3-036738-9/ch3/videoBlank.html?/ebook/products/0-13-03673
8-9/video/vtchromo.mov
Genes are carried from parents
to their offspring on chromosomes
3. During meiosis, the chromosome:3. During meiosis, the chromosome:
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See pg. In textSee pg. In text
The chromosome pairs
separate and are distributed
to two different cells. The
resulting sex cells have only
have half as many
chromosomes as the other
cells in the organism.
4. ____________________ are 4. ____________________ are
located on chromosomes.located on chromosomes.
Genes
5. Our bodies have ________ pairs of 5. Our bodies have ________ pairs of
chromosomes that contain over chromosomes that contain over
__________ genes.__________ genes.
23
60,000
Chapter 3 Genetics: Chapter 3 Genetics:
The Science of The Science of
HeredityHeredity
Section 4: The DNA Section 4: The DNA
ConnectionConnection
Section 4: The DNA Connection -Section 4: The DNA Connection -
Objectives:Objectives:
To explain the term “genetic code”:To explain the term “genetic code”:
To describe the process by which a cell To describe the process by which a cell
produces proteinsproduces proteins
To describe different types of To describe different types of
mutations and how they affect an mutations and how they affect an
organism.organism.
17. 17. messenger RNAmessenger RNA
RNA that copies the coded message RNA that copies the coded message
from DNA in the nucleus and carries from DNA in the nucleus and carries
the message into the cytoplasmthe message into the cytoplasm. .
18. 18. transfer RNAtransfer RNA
RNA in the cytoplasm that carries an RNA in the cytoplasm that carries an
amino acid to the ribosome and adds it amino acid to the ribosome and adds it
to the growing protein chain.to the growing protein chain.
NotesNotes
1. The main function of genes is to:1. The main function of genes is to:
Control the production of
proteins in the organism’s cells.
Proteins help to determine the
size, shape, and many other
traits in an organism.
2. The _________ of 2. The _________ of
_______________ bases along a _______________ bases along a
_____________ forms a genetic code _____________ forms a genetic code
that specifies what type of that specifies what type of
___________ will be produced.___________ will be produced.
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eneti.mov
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rotei.mov
order
nitrogen
gene
protein
3. A _____________ is a change in a 3. A _____________ is a change in a
___________ or ___________ or
____________________.____________________.
DNA mutations: DNA mutations:
http://www.youtube.com/watch?v=_ajRf8yMBe0
mutation
gene
chromosome
4. Mutations can be:4. Mutations can be:
A. ____________ and an example A. ____________ and an example
would be ______________.would be ______________.
B. ____________ and an example would B. ____________ and an example would
be ______________.be ______________.
C. ______________________ and an C. ______________________ and an
example would be ______________.example would be ______________.
Harmful
Helpful
Neither harmful or helpful
cancer
Antibiotic resistance in bacteria
A white buffalo color on
a farm (versus a white
buffalo color in the wild)