Transcript Who is Gregor Mendel?

1. Who is Gregor Mendel?
An Austrian monk who disproved the idea of
“blended inheritance” more than 150 years ago.
“Father of Genetics”
2. Mendel is known as the _________________________
3. Why did Mendel study pea plants?
1. They reproduce quickly. Many plants = lots of data
2. Easily observable traits, such as flower color and pea
shape
3. Mendel could easily control plant reproduction
4. Explain what happened during Mendel’s
first generation crosses (p. 392)
a. Purple x Purple =
All purple
b. White x White = All white
c. Purple x White (both true-breeding) = All purple
5. When Mendel bred a true-breeding purple and a truebreeding white plant he got all purple offspring. Is this what
you would have expected? Why or why not?
Most people would probably expect to have
half purple and half white flowers.
Most would not expect to have no white flowers at all!
6. Explain what happened during Mendel’s
second generation crosses (See page 393)
a. Purple hybrid x Purple hybrid =
Purple and white offspring!
7. By studying pea plants Mendel was
able to determine that some traits are
_____________
while others are
dominant
blocked or _________________.
recessive
Define:
8. Heredity - The passing of traits from
parents to offspring
9. Genetics - The study of how traits are
passed from parents to offspring
10. Dominant Trait –
A genetic factor that blocks another
genetic factor
11. Recessive Trait -
A genetic factor that is blocked by the
presence of a dominant factor
Do an organism’s characteristics and
traits mix (like colors of paint) to
resemble both their parents? Explain.
Usually No,
children are not a perfect mixture of their parents’ traits!
Heredity
______________
is the passing of
traits from parents to offspring,
Genetics
while _______________
is the
study of how traits are passed
from parents to offspring.
Mendel’s Experimental Methods
Pollination in pea plants can occur through both
self
cross
_______-pollination
and ________-pollination
What is cross-pollination?
When pollen from one plant reaches the pistil
of a flower on a different plant.
What is self-pollination?
When pollen from a flower pollinates
the same flower or another flower in
the same plant.
Which type of pollination?
Cross-pollination
Self-pollination
List the 4 main steps of Mendel’s crosspollination technique (page 391)
1. Mendel removed the stamens from the purple
flower.
2. He transferred pollen from the stamens of the
white flower to the pistil of the purple flower.
3. The pollinated pistil of the purple flower grew into
a pea pod. Then Mendel planted the peas.
4. The peas grew into plants.
Add to notes: not in packet
True-breeding – has genes for the same trait
B= brown, b= blue (example: BB, bb)
Hybrid – has different genes for the same trait
(example: Bb)
When a true-breeding plant selfpollinates, it always produces offspring
match the parent
with traits that __________________
(page 391)
Hybrid plants came from truebreeding parent plants with different
forms of the same trait
________________________
(page 393)
When Mendel crossed two hybrids for
a trait, the trait that had disappeared
3:1
then reappeared in a ratio of _____.
Look at page 394. What traits are dominant??
Mendel’s Conclusions (page 395)
2 genetic
1. Mendel concluded that ______
factors control an inherited trait.
2. When organisms reproduce each
1 factor
reproductive cell contributes _____
for each trait.
3. Mendel hypothesized that in hybrid crosses
the purple factor in pea plants is the only
factor seen or expressed because it blocks the
white factor. This means that the purple trait
dominant
is ______________
, while the white trait is
________________.
recessive
4. A recessive trait is only observed when
two recessive genetic factors are present.
__________________________
5. In a second generation of pea plant hybrids,
about ______
percent of the plants had
75
purple flowers. This means that plants had at
least _______
dominant factor. Twenty-five
one
percent of the second generation plants had
white
_________
flowers, which means these plants
had ______
two recessive factors.
Read page 397 and answer the
following questions.
1. Other than a monk and scientist, Mendel was
also a ______________________.
Gardener and Beekeeper
2. What year was human DNA completely
2003
mapped? ________________
3. What two scientists discovered the structure of
Francis Crick and James Watson
DNA molecules? ______________________
Inherited Traits Inventory
What are YOUR visible traits??
What is your phenotype???
Do you have detached earlobes??
I have a hitchhiker’s thumb
Can you roll your tongue??
Do you have dimples?
Are you right-handed?
Do you have freckles?
Do you have naturally curly hair?
Do you have a cleft chin?
Do you have allergies?
Do you have a widow’s peak?
Do you cross your left thumb over
your right thumb?
Can you see the colors red and green?
I have brown eyes
I have mid-digital hair
My second toe is longer than my big toe
Can you taste P.T.C.?
Interview 5 Family Member (in person or
over the phone) and get signatures!!
Answer follow-up questions on back!!
DUE: Next Monday!!