part 2: heredity and mendelian...
TRANSCRIPT
Part 2: Heredity and
Mendelian Genetics
The Genetics of Inheritance
Traits – _______________________
_____________________________.
Ex. Earlobes, Dimples, Curved
Fingers, Rolling Tongue
Inheritance – The mechanism
that _______________
___________________ between
generations.
Genetics – The branch of biology that
deals with the _________________
_____________________________
Farmers knew about ______________
________________before these
principles were scientifically proven.
People have been ________________
domesticated __________________ for
millennia.
The __________________of how
these processes occurred were
unknown.
The Greek philosophers:
____________, 460-377 B.C.E.,
suggested that the body produced
“__________” and that these seeds _____
to give rise to a _________________.
A few theories arose…
__________, 384-322 B.C.E.,
proposed that ________________
mixed upon conception.
In the 1500’s, English physician,
_______________ theorized that a
process called __________was how
inheritance occurred. A process based
upon the development of the ________
_____________, and affected by
___________________________ the
mother.
Dutch Scientist and Microscopist, ______
_________________, used a microscope
in the mid to late 1600’s to examine the
__________________and other animals.
Leeuwenhoek later proposed that the
male sperm actually contained ____
______________ which would later be
_____________ in the mother’s uterus.
Preformation
Theory
Sperm and Egg at Conception
Charles Darwin suggested, in the mid 1800’s
that children had characteristics that were
___________________________ , but he
was unable to explain the _______________.
The answer to ________________ came
from Darwin’s contemporary ___________
Mendel’s Contributions
“The Father of Modern
Genetics”
Gregor Mendel 1822-1884
The Inheritance of One Trait
Gregor Mendel, an Austrian monk,
studied the ____________________
using the common _________________
as an experimental model.
Prior to Mendel’s work at the Monastery of
St. Thomas in Brunn, he attended the
University of __________.
While at the University, his studies
included ___________________ –
training that would later prove to be
invaluable.
Why did Mendel choose the
pea plant (Pisum sativum) as
an experimental model for his
study?
The position of the _____________ of the
plant are entirely __________________;
this allowed Mendel control over ______
_______________________.
The plants exhibited ____________
___________________between
generations. Each trait had only ______
________________________________.
How did Mendel set up his
experiment?
The first thing he did was _________
______________________ for each of
the traits he wished to study.
This process ensured he was working with
plants that ____________________.
i.e. the plants produced __________
__________ when any _________of the
same _____________were bred together.
Mendel prepared a __________ for each
of the ___________ he studied.
Each of these ___________were easily
identified in the _______________ of the
offspring generation.
The seven traits were:
Before we jump in:
- Solving genetics problems involves an
____________________ (the measure of
how likely an event is).
Complete the following:
Mathematically
To determine probabiliy:
# of ways an event can occur
Total # of Outcomes
=
A Monohybrid Cross
Mendel’s first experiment involved the
________________________________
___________________. Mendel called
this the ________________________.
From this cross, the offspring were
referred to as the _________________
These were called _________ because
they resulted from the ______________
________________________________.
This type of cross is called ________
because only ___________________,
was involved.
A monohybrid cross…
____________
____________
__________________
__________________
__________________
_________________
_________________
_________________
_________________
_________________
The results of the experiment
Mendel’s first experiment showed that a
_________________________________
________________________. That is, all
of the ____________________________.
This led Mendel to conclude that the trait
for _________________________over
the _____________________________.
Dominant & Recessive Traits
Dominant Trait – a characteristic that is
__________________________. Only
_______________________ must be
present for the _____________to be
expressed.
Recessive Trait – a trait that is ________
______________________ that code for
the ___________________are present.
In Mendel’s experiments, he found that one
__________________________________
__________________________________.
Mendel’s Principle of
Dominance
When ________________________
______________, the offspring will
only express the _______________
_____________________________.
Back to Exp. 1 – Monohybrid Cross
Punnett
Square Tall Plant
T T
Short
Plant t
t
Mendel’s next experiment involved the
crossing of ___________________
__________________. He allowed the
__________________________ to
undergo ____________________.
Exp. 2 – Monohybrid Cross with F1
Offspring
Punnett
Square Tall Plant
T t
Tall
Plant T
t
This produced a ________________, that
Mendel called the ___________. ________
of plants in the F2 generation were ________
_______________________
This ratio of _____ has become known as the
________________________.
Mendel drew four conclusions from his
experiments:
Each parent in the F1 generation
begins with __________________.
Individual ______________________
_______________________________
The factors are ________________
and each ___________________ factor
to each _____________.
Each offspring ________________ from each
parent. If the ___________________ by the
offspring, it will be _____________; even if the
____________________________.
The recessive factor will _________________
_____________________________________
.
The Law of Segregation
Inherited traits are ________________
___________. These factors _________
____________ when the _________ are
formed. One factor from __________
______________ in each gamete.
F1 Hybrid Cross (Showing
Segregation)
What are “factors”?
We now know that Mendel’s factors _____
________. A _____ can occur in _______
_________________________________
When _____________ are present, a
_____________________ and the
_____________ is not. Each of these
__________ will pass on to the ______
___________ where they may or may not
__________________.
The arrangement of alleles.
Alleles can be identified by using a
________________________________.
i.e.
The ________________usually determines the letters
of the _____________________for the code. For
example the ___________________would be ____,
with both ________________________for a
dominant trait. The code for a __________________.
If the code read ____, it should be
understood that this individual would be
________________________________
________________________________.
The arrangement in which both alleles
are represented by the ______________
______________________________
To clarify, one must indicate the organism
as being either ____________________
_________________________________
_________________________________
The arrangement in which both alleles
are represented by _______________
________________________________
The following terms will help you read
about and describe heredity:
________________________________
________________________________
________________________________
________________________________
A tall-stem pea plant could have two
_____________________________.
A short-stem pea plant can have only
___________________ since the
allele for ________________________
________________________________
Phenotype refers to the
_____________________________.
Since a pea plant can be tall or
short, there are _______________
______________________________.
The tall phenotype may have _____
______________________________
Sample Problem 1
Consider a cross between a pea plant that is heterozygous
for round seeds and a pea plant that has wrinkled seeds.
Determine the genotypes of the possible offspring.
Sample Problem 2
A plant that is homozygous for purple flowers is
crossed with a plant that has white flowers. If the
purple condition is dominant over the white
condition, what are the genotypes and
phenotypes of the F1 generation?
Sample Problem 3
Determine the genotypes of the parents if the following
offspring are produced.