Download 14.1 Test Cross and Law of independent assortment

By: Savannah Rodamer












Alleles- alternative versions of a gene
Dominant Allele- determines the organisms appearance
Recessive Allele- has no noticeable effect on the organisms appearance
Law of segregation- two alleles for a heritable character segregate during gamete
formation and end up in different gametes
Punnett square- diagrammatic device for predicting the allele composition of offspring
from a cross between individuals of known genetic makeup
Homozygous- Organism that has a pair of identical alleles
Heterozygous- Organism that has two different alleles for a gene
Phenotype- Organisms appearance/physical traits
Genotype- Organisms genetic makeup
Monohybrids- individuals heterozygous for one character
Dihybrids- individuals heterozygous for two characters (YyRr)
Law of Independent assortment- each pair alleles segregates independently of each other
pair of alleles during gamete function





Test Crossing was first introduced by Gregor Mendel
It is used to determine if a group that has a dominant trait is
homozygous or heterozygous for that particular trait
Test crosses determine the genotype of an individual with a
dominant phenotype
The genotype of an offspring is determined by the allele
inherited from its parents
There is a monohybrid cross and a dihybrid cross
Basic principle of genetics and occurs in meiosis
Alleles for different traits separate when gametes
are formed without influencing inheritance
 At fertilization, the alleles randomly unite


Mendel first used pea
plants to show the
law of independent
assortment. Using a
green pod that
produced yellow
seeds and a yellow
pod that produced
green seeds to
represent a dihybrid
cross

If a tall tomato plant has the dominant allele
T and a dwarf tomato plant has the recessive
allele t. Create a punnet square.
T
t
T TT Tt
t Tt tt




What is a test cross used for?
A:To determine an individuals genotype
During gamete formation genes for different
traits separate without influencing each
other’s inheritance. This illustrates which
Law?
A: Law of Independent Assortment

http://www.youtube.com/watch?v=Y1PCwxU
DTl8




http://en.wikipedia.org/wiki/Test_cross
http://lifesci.rutgers.edu/~mcguire/toolboxdemo/Testcross/test_cross.htm
http://biology.about.com/od/mendeliangenet
ics/ss/independent-assortment.htm
http://biology.about.com/library/glossary/bld
efmenlawia.htm