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Genetics
GENETICS
1-3
name_________________________________________
The branch of biology that deals with ________________
Mendel
A great deal of what we know about genetics began with the work of a monk named
________ ___________,. He experimented with sweet ___________________
plants
Mendel studied the ______________ of inheritance in pea plants. He chose ______
traits to follow.
Vocabulary check:
5-6.




The female part of the plant is called the
________________, and the male part of the plant
is called the ________________.
Self-pollination is when the sperm of a plant
fertilizes the egg of the ________________ plant.
Cross-pollination is when the sperm of one plant
fertilizes the egg of ________________ plant.
A plant that always gives the same type of offspring
is called ________________________.

7-8
Mendel’s Experiments:
P-generation: _______________ x ___________________
F1 generation:
F2 generation:
100% __________________
Which two colors did he cross from the F1?
75% ______________ & 25% ___________
Mendel’s Conclusions:
9-10
2.
Something is being passed from parent to
offspring. He called these “_________________”.
3.
Sometimes you ________ see “it” and sometimes
you _______ see “it”.
4.
11.
If you can see it- it is ________________.
1.
If it’s there and you can’t see itit’s__________________.
5.
6.
There are ________ versions of these “FACTORS”.
7.
Each Version is called an _______________.
To show the two version we use a ____________
letter for the dominant (S) version of the trait and
__________ case for the recessive version (s) of the
trait.
 Each chromosome has ___________ ___________,
but the alleles may be ________________
 Alleles are different versions of the _________ gene.
Vocab Word: Locus
15. Chromosome Anatomy.
16. We have two copies of all of our chromosomes How did that happen?
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
What is a Gene?
19. • A ____________ on
the chromosome that
codes for a
___________.
• There are many
versions of each
gene- __________.
PRACTICE:
Homozygous- or
Heterozygous-
BB: __________
Bb:___________
Tt:___________
20-21.
Rr:___________
VOCABULARY CHECK:
GENOTYPES:
Homozygous
Heterozygous
RR:___________
 2 alleles in the pair are __________________
 The term “______________” is sometimes used.
 2 alleles are __________________
 The term “__________” is sometimes used
Genotype
 What the ______________/alleles are
Phenotype
 What the organism __________ like
Genetic variation gives rise to differences between individuals that are inherited. For example, our eye color is inherited from
our parents. But our phenotype is also affected by environmental variation such as:
Climate, diet, physical accidents, culture, lifestyle
Many kinds of variation are influenced by both environmental and genetic factors, because although our genes decide what
characteristics we inherit, our environment affects how these inherited characteristics develop. For example:
a person might inherit a tendency to be tall, but a poor diet during childhood will cause poor growth
plants may have the potential for strong growth, but if they do not receive sufficient mineral resources from the soil,
they may hardly grow at all
Identical twins are a good example of the interaction between inheritance and environment; as such twins are genetically the
same. Any differences you may see between them – for example in personality, tastes and particular aptitudes – are due to
differences in their experience or environment.
23. Question: How did you end up with the traits and genes that you have?
A: During ________________, each egg or sperm only gets_____________ ____________ of each chromosome.
24.
Mendel’s Laws
Law of Dominance
Law of Segregation
States that the
_________________
allele will prevent the
recessive allele from being
expressed. The recessive
allele will appear when it is
______________ with
_____________ recessive
allele in the offspring.
(separation)
 States __________
__________
______________ when
gametes (sex cells) are
formed
Each gamete has only
_______ ___________
of each gene pair. (haploid)
Law of Independent
Assortment
States that
_______________
________________ of
genes separate
___________________
of each other when
gametes are formed.
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
2
27. A
Review:
1. A _____________ is a characteristic an
individual receives from its parents.
2. _______________carry the instructions
responsible for the expression of traits.
3.
4.
5.
A ____________ of inherited genes controls a trait.
One member of the pair comes from each
_______________.
Alternative versions of genes are known as
________________.
30: Predicting possible outcomes of a genetic cross
31.
Geneticist use punnett squares to determine the probability of a combination of alleles.
•
For example: If a heterozygous black rabbit is crossed with a heterozygous black rabbit,
what are the chances the offspring will be black?
B=Black and b=brown
( which one is dominant? _____________)
32. Sample EOC question:
Earlobe shape is a human trait. Some people have free earlobes while others have attached earlobes.
Two parents with free earlobes have four children. Three children have free earlobes and one child
has attached earlobes. If these parents have another child, what is the probability that the child will
have attached earlobes?
33. Sample EOC question:
In humans, a widow’s peak is dominant over a continuous hairline. Mary’s father has a widow’s peak,
but Mary and her mother have a continuous hairline. What is the genotype of Mary’s father?
Genetics Vocab #1 Quiz on ___________
1. Genetics
Vocabulary Practice:
2. Phenotype
3. Genotype
4. Chromosome
5. Alleles
6. Diploid
7. Haploid
8. Homozygous
9. Heterozygous
10. Fertilization
11. Pollination
12. Trait
13. Hybrid
14. Gene
15. Locus
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
Monohybrid Genetic Crosses: An Activity
1.
2.
3.
Turn your cards upside-down, so that you cannot see the letters.
Each person should flip over one card at a time. (This represents the fusion of an egg and a sperm.)
Every time you flip over a card, write down the results. After to write down the results, return your card to your
stack and shuffle them. This needs to be random.
a. 1st time____________
b. 2nd time____________
# of times AA? _______
c. 3rd time____________
# of times Aa? ________
d. 4th time____________
# of times aa? ________
e. 5th time____________
Total number of rounds? ________
(times you flipped)
f. 6th time ____________
4.
5.
6.
7.
What percentage of time did you get AA? _____________
What percentage of time did you get Aa? _____________
What percentage of time did you get aa? _____________
Create a punnett square showing the cross of you and your partners original genes.
1 partners
genes
(genotype)
here- one
letter in
each box
8.
The other
partner’s genes
(genotype) here
What does a punnett square show?
Questions about your punnett square:
9. What percentage of time should you expect to get AA? _____________
10. What percentage of time should you expect to get Aa? _____________
11. What percentage of time should you expect to get aa? _____________
Post Activity Questions:
12. How do the results of the punnett square compare to the card flipping activity?
13. What does each square of the punnett square represent?
14. What does monohybrid mean?
Extension:
1.
2.
3.
Obtain 2 more genes for a different trait (B, b).
Turn all 4 of your cards upside down.
Each partner should flip one gene from each gene pair. Write down the combination.
a. 1st time____________
b. 2nd time____________
c. 3rd time____________
4.
If these were Mendel’s peas and A=tall & a= short, and B= purple & b= white. What would your plants in #3 look like?
a. 1st time___________________________
b. 2nd time___________________________
c. 3rd time___________________________
5.
From #3, did the “A” genes predict which “B” gene the offspring would get, or vice versa? Which of Mendel’s laws
does this represent?
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
Punnett Square Practice Problems (Monohybrid)
1. For each genotype below, indicate whether it is a heterozygous (He) OR homozygous (Ho).
TT _____ Bb _____ DD _____ Ff _____ tt _____ dd _____
Dd _____ ff _____ Tt _____ bb _____ BB _____ FF _____
Which of the genotypes in #1 would be considered purebred? _______________________________
Which of the genotypes in #1 would be hybrids? __________________________________________
2. Determine the phenotype for each of the genotype using the information provided.
Yellow body color is dominant to blue.
YY _________________ Yy _________________ yy _________________
Square shape is dominant to round.
SS _________________ Ss _________________ ss _________________
Problems:
Problem #1 –Both Matt and his wife are heterozygous for the tall trait. Use a Punnett
square to predict the genotypic and phenotypic outcome for their children.
a. Genetopic ratios? ________________________________
b. Phenotypic ratios? ________________________________
c. What is the chance that they will have a short child? ______
d. What is the chance that their child will also be a heterzygote?
_______
Problem #2 - In pea plants, yellow peas are dominant over green peas.
Use a Punnett square to predict the phenotypic and genotypic outcome (offspring)
of a cross between a plant heterozygous/hybrid for yellow peas and a plant
homozygous recessive/purebred for green peas.
a. Genetopic ratios? ________________________________
b. Phenotypic ratios? ________________________________
Problem #3 - In pea plants, yellow peas are dominant over green peas.
Use a Punnett square to predict the phenotypic and genotypic outcome (offspring)
of a cross between two plants that are both heterozygous for yellow peas.
a. Genetopic ratios? ________________________________
b. Phenotypic ratios? ________________________________
Problem #4: In pea plants, spherical seeds (S) are dominant to dented
seeds (s). In a genetic cross of two plants that are heterozygous for the
seed shape trait, what fraction of the offspring should have spherical
seeds? Make a Punnett square in the box to the right.
a. What fraction of the offspring should have spherical seeds? ______
b: What fraction will have dented seeds? ______
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
5
Dihybrid Crosses
#1
T=tall, t= short
Y=yellow, y = green
Cross a heterozygous tall plant that is also
heterozygous yellow seeds with another of
the same genes.
Mom’s genotype: _____________
Dad’s genotype: ______________
Possible gametes from:
Mom: ____________________
Dad: _____________________
QUESTION: What are the chances that this cross produces a plant that is short and has yellow seeds? _______
#2
T=tall, t= short
Y=yellow, y = green
Cross a homozygous tall plant that is
heterozygous yellow seeds with another plant
that is heterozygous tall and is homozygous
for green seeds.
Mom’s genotype: _____________
Dad’s genotype: ______________
Possible gametes from:
Mom: ____________________
Dad: _____________________
QUESTION: What are the chances that this cross produces a plant that is tall and has green seeds? _____
Dihybrid Cross Example:
Use the following procedure to set
up a cross:
1. Determine the genotype of the
parents.
2. Segregate the alleles to
determine the gametes
3. Construct the Punnett square
4. Complete 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
6
Meiosis summary:
Meiosis is the process by which gametes (sex cells) are produced. In males, gametes are called sperm, and in females, they are
called eggs. Meiosis reduces the number of chromosomes in the gamete to one-half the number of chromosomes in the parent’s
body cells. When fertilization occurs, the union of two gametes, a zygote is formed. Fertilization restores the original chromosome
number in the resulting zygote (new individual). Meiosis occurs in 2 phases, meiosis I & meiosis II.
**Meiosis occurs only in the formation of sex cells. This process consists of two cell divisions but only one chromosome replication.
· The first meiotic division produces two cells containing half the number of double stranded chromosomes. These are called diploid
(2n) cells.
· The second meiotic division results in the formation of four cells, each containing half the number of single stranded
chromosomes. These are called haploid (1n) cells
Sources of Variation during Meiosis
The process of meiosis provides the opportunity for the shuffling of chromosomes and the genetic information they contain.
The way that the chromosome pairs line up at the equator during meiosis influences how they are distributed to the gametes. For
example, Mendel studied the pea plant that has seven pairs of chromosomes. Each of these seven pairs of chromosomes lines up
during meiosis in two different ways, producing 128 (27) different combinations of traits. The number of possible combinations will
greatly increase as the number of chromosomes increase within a given species. Human gametes have 23 chromosomes. So the
number of different kinds of genetic combinations a person can produce is astounding—more than 8 million! When fertilization
occurs, 223 x 223 different genetic combinations can occur. That is 70 trillion!
Another source of variation during meiosis is crossing over. Crossing over occurs when two chromosomes physically overlap and
exchange chromosome material. This process occurs more often on some chromosomes than other chromosomes and changes the
DNA sequence within each chromosome. This results in an endless number of different possible genetic combinations. Whether by
crossing-over or by independent assortment of homologous chromosomes, the end result is a re-assortment of chromosomes and
the genetic information they carry. This is known as genetic recombination.
Reading Questions: (answers must come from the reading)
1. What types of cells are made during meiosis? ___________________ 2. What is fertilization? ____________________________________
3. What is meant by diploid? ________________________________________________________________________________________
4. What is meant by haploid? ________________________________________________________________________________________
5. List
1.and describe TWO ways the process of meiosis increase genetic diversity (shuffling of chromosomes).
2.
_______________________________
Genetics Review
__________________________________________________________________________________________________
1. Fill in the blanks: (Word Bank below)
Gregor Mendel, an Austrian monk, was the first to succeed in predicting how traits are carried from one generation to the next.
He used pea plants in his experiments because they reproduce sexually. He was very careful to study one trait at a time to control
the variables. He would manipulate flower parts in order to fertilize the female gamete with the male gamete in the desired parent
plants. Mendel discovered that when he crossed tall plants with short plants, the first generation of offspring (_________) were all
tall. When he let the F1 plants self-pollinate, Mendel found that three-fourths of their offspring (________) were tall and onefourth of the F2 plants were short. The short trait had reappeared in the second generation (F2). Mendel came to the conclusion
that each organism has two factors for each of its traits. Mendel called the trait that appeared in the first generation
_______________ and the trait that seemed to disappear ________________. Today, scientists call these factors
___________________.
 Genes are located on the chromosomes and can exist in alternative forms called ___________________.
 Alleles are found on different copies of chromosomes, one from the female and the other from the male.
 If the two alleles in a pair are identical, then the trait is called ___________________. If the two alleles are different, then the
trait is called ___________________. Genetic crosses that involve one trait are called _________________crosses, while
_____________ crosses involve two traits.
 Outcomes of genetic crosses can be predicted by using the laws of probability. Using a ___________ square will give the possible
results of genetic crosses.
***WORD BANK: genes, dominant, F1, F2, dihybrid, monohybrid, homozygous, heterozygous, recessive, alleles, punnett
2. List and describe 3 ways that increase genetic diversity in organisms.
1-_____________________________________________________
2-_____________________________________________________
3-_____________________________________________________
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
Genetics Web Lab
1. Utah Genetics (animation with sound)
Click on: What is Heredity?
1. The passing of traits from parents to a child is the basis of _____________________
2. Every child receives __________ of its chromosomes from his mother, and _______from his father.
3. When a sperm and egg join, they create a single cell called a __________________________
4. Each child inherits a ______________ set of chromosomes
Click on:
What is a Trait?
5. Give an example of a physical trait: ___________________________
6. A dog fetching a bone is an example of what kind of trait. _____________________________
7. Scientists describe the set of information for each form of a trait as an ______________________
2.Meiosis Animation (animation with sound)
1.
2.
3.
4.
Watch the animation
What went wrong during the 2nd division? _____________________________________________________________
What is this called? ______________________________
If this was the 21st pair of chromosomes, what genetic disorder would this cause? ____________________________
3. Cells Alive
1.
2.
3.
4.
Watch the animation and read the paragraph below (on the screen).
What does 2n mean? _________________________ What types of cells in your body are 2n? _________________________
What does n mean? __________________________ What types of cells in your body are n? __________________________
How are the cells at the end different from the cells at the beginning of meiosis? ________________________________
___________________________________________________________________________________
4. Learn Genetics: Utah: Sources of Variation:
Scroll to the bottom:
1. What is the Misconception?___________________________________________________________________
2. What is the Reality (fact)?____________________________________________________________________
On the picture that says “Sources of Variation,” click the right arrow. (turn on CC for extra help)
3.
(slide 1)
Individuals within all species ____________. (click the right arrow…do this each time to advance to the next slide)
4.
(slide 3) Diversity
5.
(slide 4) Genes
6.
(slide 5) Genes
7.
(slide 6) _____________________
8.
(slide 7) Some
9.
(slide 8)
10.
(slide 13) Skin
11.
(slide 16)
within a population begins with __________________________.
code for __________________ that make up the _________ and carry out its ______________.
come in different __________________ ____________________. These genetic variations are the
basis of ___________________ within a population.
is the primary source of variation.
mutations involve ________________________, ______________________ or
______________________ larger chunks of DNA.
When are mutations passed along to offspring? ______________________________________________
color is actually controlled by _____________________________ genes.
When does recombination happen in sexually reproducing organisms? ____________________________
What 2 events take place to make this recombination happen? 1-_____________________________________
2-_____________________________________
12.
(slide 18) The
random processes of mutations and recombination create _________________________. Selection
ensures that _________________________ varation pass to the __________ ______________________, and
that harmful mutations and gene combinations are _____________________.
Georgia
Students will analyze how biological traits
passed on to successive generations. c. Usingenable
Mendel’s
laws,
13. Biology
(slide 19)Standards:
TogetherSB2.
__________________________
and are
_____________________________
populations
8to
explain
the
role
of
meiosis
in
reproductive
variability
shift over time in response to the changing world.
8
5. Making Bunnies
Click Play. Click “View Tutorial”
From the tutorial:
-Dominant genes are represented with _________________ letters, and Recessive with a _______________- case letter.
-In this game, brown fur is ____________________ and white fur is a __________________________ trait.
Give the FINAL genotype (Aa) and phenotype (what is looks like) for each of your bunny’s traits.
Bunny Name
Fur Color
Head Shape
6. Punnett Squares:
Ear Shape
Eye Color
Gender
7. Punnett Square Lab
1.
Read the introduction and click next.
2.
Which is the dominant allele?
_________________
2. Click on the notebook and perform the crosses.
3.
What was the answer to the question? ¼,
½, ¾, or All of the time?
4.
What number was albino? _________
5.
Which 2 lemmings produced the long tailed
albino? ____ & ______
3. What were the correct offspring genotypes for “Scenario #1?”
________________________________________
4. What were the correct offspring genotypes for “Scenario #4?”
________________________________________
5. In “scenario #9,” what genotypes of the parents did you have to use to
make all the flies have vestigial (short) wings?
__________________________________________________
1. Click on the TV and watch the video. (close the TV when finished)
(click the “reset
button until “scenario 1” appears).
8: Independent Assortment (animation with sound)
(NOTE: you are watching two ways that the same cell COULD go through meiosis)
1. What are the two main processes that allow cells two create genetically diverse gametes?
1-________________________________________ 2-___________________________________________
2. A diploid cell contains _____ sets of chromosomes.
3. How one chromosome pair lines up on the plate _________ _______ affect how another pair lines up.
(BIG IDEA!!!)
4. Did the 4 gametes for the top cell end up genetically identical to the 4 gametes for the bottom cell? _______
9: Dihybrid Cross
Click “Start Animation”
1. What is a dihybrid cross? _____________________________________________________________________
2. What are the genotypes of the two parents? (you should have 4 letters each) _________ and _________
3. What is the genotype for the F1 generation? _________ What are the 4 possible gametes produced by these plants?
_____, _____, _____, _____ (2 letters each)
4. When the animation stops, list the genotypes that you had to drag starting in the top left corner…working your way
down: ________, ________, ________, ________
10: Another Dihybrid:
1.
What are the dominant phenotypes: height: ____________ color: _____________
2.
The plant is heterozygous for both traits, so what is its genotype? __________ (4letters)
3.
What are the 4 possible gametes that this plant can make? _____, _____, _____, _____ (2 letters each)
4.
Watch the 16 square Punnett square get filled in. How many of the plants are tall and yellow? _____
6.
How many are tall and green? ________ How many are short and green? ________
Georgia Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. c. Using Mendel’s laws,
5. How many of the plants are short
and
yellow?
_____in reproductive variability
explain
the
role of meiosis
9
Book Work: On your Own
PRACTICE QUESTION: How are sexual
reproduction and asexual reproduction
different?
A. Sexual reproduction produces offspring
identical to the parents, but asexual
reproduction produces offspring with traits
from both parents.
B. Asexual reproduction produces offspring
identical to the parents, but sexual reproduction
produces offspring with traits from both
parents.
C. Sexual reproduction only occurs in
multicellular organisms, but asexual reproduction
only occurs in unicellular organisms.
D. Asexual reproduction only occurs in
multicellular organisms, but sexual reproduction
only occurs in unicellular organisms.
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
10
12