Download 11-3- Exploring Mendelian Genetics

11-3- Exploring Mendelian Genetics
Mendel wondered if the gene that determines whether a seed is
round or wrinkled in shape have anything to do with the gene for
seed color? Must a round seed also be yellow or do the
_____________________separate independently.
Mendel’s next experiment is known as a __________________________ cross (or dihybrid cross).
He followed __________different _____________as they passed
from one generation to the next.
The true breeding plants were :
Phenotypes: ______ _________peas Genotype:_____ _____
Phenotypes: _____ _____peas Genotype: _____ _____
All offspring from this cross were (the F1generation):
Phenotype: _______ _______ Genotype:_____ _____
How did Mendel produce the F2 offspring?
______________________________________________________
______________________________________________________
______________________________________________________
What did Mendel observe in the F2 offspring that showed him that
the alleles for seed shape segregate independently of those for seed
color?_________________________________________________
______________________________________________________
What were the phenotypes of the F2 generation?
______________________________________________________
______________________________________________________
What was the ratio of Mendel’s F2 generation for a dihybrid or 2factor
cross?_________________________________________________
11-3 continued
Mendel’s principles:
1. The inheritance of biological characteristics is determined by
individual units known as _____________. In organisms
that reproduce sexually, genes are passed from parents to
their ____________________.
2. In cases in which 2 or more forms (or _____________) of
the gene for a single ___________exist, some forms of the
gene may be dominant and others __________________.
3. In most sexually reproducing organisms, each adult has
________copies of each gene, one from each
______________. These genes are usually segregated from
each other when _________________are formed.
4. The alleles for different genes usually segregate
_____________________ of one another. This is the Law of
__________________ _____________________.
Beyond Dominant and Recessive
Cases in which one allele is not completely dominant over another
are called _______________ ______________. In incomplete
dominance the _______________________phenotype is
somewhere in between the 2 _______________Phenotypes. In 4
O’Clock flowers the heterozygous phenotype is pink, the
homozygous dominant is red, the homozygous recessive is white.
Cross a pure red with a pure white 4 O’Clock flower below:
Codominance is when both alleles contribute to the phenotype, so
they don’t blend in the heterozygous phenotype, but both show up.
An example is in chickens with a mix of black and white feathers.
Both colors show up.
Multiple Alleles:
Sometimes more than _________possible _____________exist in
a population, but an individual can only possess 2 of them..
Examples are blood types in humans: there is A, B, or O alleles
available and humans can only have 2 of the 3 available: AA,
AO, BB, BO, OO, or AB. A and B are both dominant alleles, O is
a recessive allele, so A and B together are considered codominant,
because both show up.
Polygenic traits:
Many traits are controlled by two or more genes, and the
interaction of these genes. Examples are eye color, skin color, and
many more ______________ ______________.
Polygenic traits often show a ______________
_________________of phenotypes.
11-4 Meiosis
____________________ _________________________are
chromosomes that each have a corresponding chromosome from
the opposite-sex parent.
__________________, (2N) which means “Two sets” is used to
describe both sets of homologous chromosomes.
When there is only a single set of chromosomes, they are
called:___________________________. (N).
The process of reduction division in which the number of
chromosomes per cell is cut in half through the separation of
homologous chromosomes in a diploid cell is called
___________________________________.
Meiosis has two stages called ______________________and
___________________________.
During prophase in meiosis 1, each chromosome pairs with its
corresponding homologous chromosome to form a structure called
a _________________.
Homologous chromosomes can also exchange parts of their
chromatids in a process called _______________ _____________.
Meiosis I results in two ______________daughter cells, each with
_____________the number of chromosomes as the original cell.
Meiosis II results in ____ _________________(N) daughter cells.
MEIOSIS CREATES GAMETES (SEX CELLS) WITH HALF
THE NUMBER OF BODY CELLS!!!!
11-5: Linkage and Gene Maps
Why is Thomas Hunt Morgan important in genetic studies?
What is gene linkage?
How does gene linkage affect the usual ratios found when working
Punnett Squares?
What is a gene map?
How are the locations of genes determined on a gene map?