Download 11.1 Guided Reading PowerPoint

The Work of
Gregor Mendel
Guided Reading

Gregor Mendel


25 min
Mendel (pearson)
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6 min
The Experiments of Gregor Mendel
1.
What is Heredity?

2.
What is Genetics?

3.
the science of the study of heredity
The modern science of genetics was founded by

4.
The delivery of characteristics from parents to offspring
an Austrian monk named Gregor Mendel
What plant did Mendel use in his experiments?
Why?
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Pea plants – they are easy to grow
The Role of Fertilization
5.
Describe the reproductive structures of a
flower.

6.
What happens during fertilization?

7.
the male parts produce pollen, which contain sperm, and
the female parts produce eggs
the male and female reproductive cells join to produce a
new cell, which develops into an embryo
What does ‘self-pollinating’ mean?

the sperm cells (pollen) fertilize the egg cells within the
same flower, which can produce offspring identical to the
parent plant
8.
The plants in Mendel’s garden were
‘true-breeding’ which means that
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9.
they were self-pollinating and would produce
offspring identical to themselves
A trait is

a specific characteristic of an individual, such as
seed color or plant height.
10. Many

traits
vary from one individual to another.
11.
What did Mendel do to learn how traits
were determined?

He cross-pollinated his true breeding plants by dusting
the pollen of one plant onto the female parts of another
flower. He crossed a plant showing one version of the
trait with a plant showing the other version.
12.
Mendel studied seven different traits of pea
plants. Each of these seven traits had two
contrasting characteristics, such as green seed
color or yellow seed color.
13.
What are hybrids?

offspring of crosses between parents with different
traits
Genes and Alleles
14.
When doing genetic crosses, what are the
original pair of plants called?

15.
The offspring of the P generation are called the

16.
P (parental) generation
F1, or first filial, generation
After Mendel crossed two plants (P
generation), what were the F1 plants like?

for each trait he studied, all of the offspring had the
characteristic of only one of its parents. The other trait
seemed to have disappeared
17. What

An individual’s characteristics are determined
by factors that are passed down from one
parental generation to the next
18. What

are these factors now called?
Genes
19. What

was Mendel’s first conclusion?
are alleles? Give an example.
The different forms of a gene. Plant height has
two alleles – tall and short.
Dominant and Recessive Alleles.
20.
What was Mendel’s second conclusion?

21.
The principle of dominance states that
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22.
The principle of dominance
some alleles are dominant and others are recessive.
An organism with at least one dominant
allele for a particular trait will

exhibit that form of the trait.
23. An
organism with a recessive allele
for a particular trait will

exhibit that form only when the dominant
allele for the trait is not present
24. For
the plant height trait, which
allele is dominant and which is
recessive?

Tall is dominant to short height
Segregation
25. After
producing the F1 generation,
what was Mendel’s question?

had the recessive alleles simply disappeared,
or were they still present in the new plant?
26. What
are the offspring of the F1
plants called? How did he produce
them?

F2 generation – he self-fertilized the F1 plants
The F1 Cross
27. What
was Mendel’s discovery when
comparing the F2 plants?

the traits cotrolled by the recessive alleles
reappeared in the second generation
28. What
amount (percentage) of the F2
generation had the recessive trait?

one fourth (25%)
Explaining the F1 Cross
29. What

did Mendel initially assume?
dominant allele masked the recessive allele in
the F1 generation
30. What
did the reappearance of the
recessive trait indicate?
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The recessive allele had separated from the
dominant allele
31. What

are gametes?
sex (reproductive) cells – sperm and eggs
The Formation of gametes
32. What
happens to an individual’s
alleles during gamete formation?

the alleles for each gene segregate from each
other, so that each gamete only carries one
allele for each gene
33. When
do the alleles pair up again?
(see Figure 11-5)

during fertilization