Transcript Mendel Discovers “Genes” 9-1

The Work of
Gregor Mendel
11-1
http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
http://www.jic.bbsrc.ac.uk/germplas/pisum/zgs4f.htm
Objectives:
• -Describe how Mendel studied inheritance
in peas
• Summarize Mendel’s conclusion about
inheritance
• Explain the principle of dominance
• Describe what happens during segregation
Transmission of characteristics from
parents to offspring
_______________________is
called
___________________.
heredity
how those
SCIENCE that studies _____
The _________
characteristics are _________
passed on from one
generation to the next is called
Genetics
___________________
http://www.jic.bbsrc.ac.uk/germplas/pisum/zgs4f.htm
The __________________
Father of Genetics is
_________________,
Gregor Mendel
study
a monk whose _________
of
genetic traits was the beginning of
our _________________
about
understanding
_____________________.
how genes work
http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif
Mendel designed
experiments using
____________
Pea plants in the
__________
monastery garden
_______
MALE part of flower makes
Pollen
___________
(sperm)
FEMALE
__________ part of flower makes
_______
egg cells
http://www.cedarville.edu/academics/education/resource/schools/chca/2scideb/debwebpv.htm
In pea plants, the pollen normally joins
with an egg from the _______
same plant
(=_______________
Self pollinating ) so seeds have
“_________________”
ONE parent
http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif
MENDEL’S PEA EXPERIMENTS
Mendel started his experiments with
peas that were _________________
true breeding
= if allowed to
_________________
self pollinate
they would produce
____________________
offspring identical
to themselves.
http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif
MENDEL’S PEA EXPERIMENTS
removed pollen
Mendel ____________________
making parts and ____________
added pollen
from _______
another plant.
This allowed him to
_____________
cross-breed plants
with ______________
different
characteristics and
study the results
________
http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif
specific characteristic is
A _____________________
trait
called a ____________
Mendel ______________
studied 7 traits in peas.
Pearson Education Inc,; Publishing as Pearson Prentice Hall
MENDEL’S EXPERIMENTS
P1 generation
____
(_________)
parental
F1 generation
____
filial
(______=
offspring)
F2 generation
___
Principles of Dominance
Section 11-1
P Generation
Tall
Go to
Section:
Short
F1 Generation
Tall
Tall
F2 Generation
Tall
Tall
Tall
Short
Principles of Dominance
Section 11-1
P Generation
Tall
Go to
Section:
Short
F1 Generation
Tall
Tall
F2 Generation
Tall
Tall
Tall
Short
Principles of Dominance
Section 11-1
P Generation
Tall
Go to
Section:
Short
F1 Generation
Tall
Tall
F2 Generation
Tall
Tall
Tall
Short
crossed PURE PLANTS
When Mendel ______________
with 2 ______________
traits:
contrasting
(EX: Tall crossed with short)
He always found same pattern:
1. ONLY ______
ONE trait ____________
showed
F1
in the ____
generation BUT . . .
Missing trait ____________
returned in
2. ___________
F2 generation
the ____
in a _________
3:1 ratio
PATTERNS ARE THE KEY
Image modified from:
http://www.laskerfoundation.org/rprimers/gnn/timeline/1866.html
http://www.accessexcellence.org/AB/GG/mendel.html
Mendel decided that there must
be a __________________
that
pair of FACTORS
control
________each
trait and that
__________
one factor must be able to
_______
HIDE the other.
We now know that Mendel’s
factors are genes carried on
________________
the pair of________________
homologous
_________________
chromosomes
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif
________
DIFFERENT gene
CHOICES for a
_______
trait are called
___________.
ALLELES
http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
DOMINANT
__________________
= An allele
HIDES the presence of
that ________
another allele
RECESSIVE
__________________
= An allele
that __________________
the
is hidden by
presence of another allele
Why did the recessive trait disappear
in the F1 generation and reappear in
the F2?
The pattern corresponds
movement of
to the ____________
chromosomes during
______________
MEIOSIS
____________________
Image modified from:
http://www.laskerfoundation.org/rprimers/gnn/timeline/1866.html
WHAT DOES MEIOSIS HAVE
TO DO WITH IT?
REMEMBER
_____________
HOMOLOGOUS
chromosomes
SEPARATE
________________
during
ANAPHASE I
= _________________
SEGREGATION
Image modified from:
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif
____
F1 offspring __________
received an allele for
tallness from their _______
TALL parent and an
allele for shortness from their ________
SHORT
parent.
The F1 plants ALL ___________
LOOK TALL
carryingan
but are ___________
allele for _____________
shortness
Images from: BIOLOGY by Miller & Levine; Prentice Hall Publishing ©2006
EXPLAINING the F1 CROSS
SEGREGATION
LAW OF ___________________
alleles are separated
when the F1 plants
______________
made gametes
When these gametes recombined to make the
recessive
F2 generation, the _____________
trait
_______________
reappears in ¼ of the offspring
Image from: BIOLOGY by Miller & Levine; Prentice Hall Publishing ©2006
Core High School Life Science
Performance Descriptors
High school students
performing at the
ADVANCED level:
predict the function of a given structure;
predict the outcome of changes in the cell cycle;
INTRODUCTION TO BE ABLE TO DO LATER
High school students
performing at the
PROFICIENT level:
describe the relationship between structure and function
compare and contrast the cell cycles in somatic and
germ cells;
INTRODUCTION TO BE ABLE TO DO LATER
predict how traits are transmitted from parents to offspring
explain how traits are transmitted from parents to offspring;
High school students
performing at the
BASIC level
recognize that different structures perform
different functions
describe the life cycle of somatic cells;
INTRODUCTION TO BE ABLE TO DO LATER
identify that genetic traits can be transmitted from parents to
offspring;