Upload
jrohara
View
805
Download
0
Tags:
Embed Size (px)
Citation preview
Genetics Vocabulary
Genetics- The branch of biology that studies biological
_______________________.
Genetics Vocabulary
Gametes = _______________ cells
SPERM EGGS
Genetics VocabularySelf-Pollination- When
______________ from a plant ______________________ an egg
from the same plant (this is how pea plants normally reproduce.)
Genetics VocabularyCross-pollination- produces
_______________ that are the offspring of two different plants.
Pollen from one plant is dusted onto the ____________ of another.
This allow scientists to
manipulate which plants reproduce
together.
Genetics Vocabulary
True-breeding- if allowed to self-pollination
______________ peas would produce offspring
______________ to themselves.
Tall pea plants only reproduce with tall for
many generations
Genetics Vocabulary
Traits –
_______________
Genetics Vocabulary
Hybrids – organisms produced by __________________
parents with different _____________________
Example- crossing a tall pea plant with a short pea plant.
Genetics Vocabulary
Genes – The factors that ____________________ traits.
Today we know these genes are
located on specific sections of DNA.
Puggles
Labradoodles
Jackapoos
Chiweenies
Genetics Vocabulary
Alleles- Different forms of a _______________________
2 different alleles for a gene in a pea plant
•Tall or short
•Yellow or green
Genetics VocabularyDominant – the alleles that are
“________________” than others
In Pea Plants
Tall is Dominant to short.
Genetics VocabularyRecessive – the
________________ form of a gene
In Pea Plants
Only shows up if two are present.
Short + short = short.
Genetics Vocabulary
Punnett Square – a diagram used to determine the
____________________ of offspring from a particular cross.
T = Tall
t = short
Genetics Vocabulary
Phenotype – the physical characteristics of an organism
TALL
YELLOW
BLUE EYES
RED HAIR
PINK PETALS
Genetics Vocabulary
Genotype – what an organism genetic makeup looks like
TT GGTt
gg
YY
Genetics Vocabulary
Homozygous – has two of the same alleles.
TT GGtt
gg
YY
Genetics Vocabulary
Heterozygous – 2 different genes
Tt GgYy
Gregor Mendel
• Gregor Mendel, a monk in the Czech Republic, is considered the "Father of Genetics", based upon experiments he conducted using garden peas. He helped lay down the principles of modern genetics.
Mendel’s Experiments
• Mendel was given a garden of pure bred pea plants.
• He studied various traits in pea plants
The First Generation Cross (f1)
Mendel Crossed a purebred tall with a purebred
short plant and
got all tall
plants!
Step one = Define the Parents Genotype and Phenotype
XTall ShortPhenotype =
Genotype = TT X tt
The First Generation Cross (f1)
ShortXTallPhenotype
Genotype TT X tt
Step two = Set up the punnett square
T T
t
t
Mendel Crossed a purebred tall with a purebred
short plant and
got all tall
plants!
Phenotype =
Genotype =
The Second Generation Cross (f2)
Mendel Crossed a
two heterozygous Tall
pea plants
Step one = Define the Parents Genotype and Phenotype
XTall TallPhenotype =
Genotype = Tt X Tt
The Second Generation Cross (f2)
TallXTallPhenotype
Genotype Tt X Tt
Step two = Set up the punnett square
T t
T
t
Mendel Crossed a purebred tall with a purebred
short plant and
got all tall
plants!
Phenotype =
Genotype =
Review Mendel’s Conclusions• The factors that control heredity are individual units known
as genes. In organisms that reproduce _________________, genes are inherited from each parent.
• In cases in which two or more forms of the gene for a single ___________ exist, some forms of the gene may be dominant and the other may be recessive.
• The two form of each gene are segregated during the formation of reproductive cells.
• Two genes for different traits may ___________ _____________________ of one another.
Sample Problem #1
A yellow pod plant is crossed with a heterozygous pod plant. What is the genotype and phenotype of the offspring?
Sample Problem #2
A white flower pea plant is crossed with a homozygous recessive flower plant. What are the genotype and phenotypes of the offspring?
Sample Problem #3
A heterozygous tall plant is crossed with a homozygous tall plant. What is the genotype and phenotypes of the offspring.
Selected Traits in Cats
Trait Dominant Allele Recessive Allele
Coat Length Short Hair (H) Long Hair (h)
Tabby Stripes Tabby (T) Stripeless (t)
Color point (markings on nose, ears, paws, and
tail)
Normal Color point
Sample Problem #4A color point cat is crossed with a heterozygous normal cat. What are the expected genotypes and phenotypes of their offspring?
Selected Traits in Cats
Trait Dominant Allele Recessive Allele
Coat Length Short Hair (H) Long Hair (h)
Tabby Stripes Tabby (T) Stripeless (t)
Color point (markings on nose, ears, paws, and
tail)
Normal Color point
Sample Problem #5A homozygous tabby cat is crossed with a stripeless cat. What are the expected genotypes and phenotypes of their offspring?
Selected Traits in Cats
Trait Dominant Allele Recessive Allele
Coat Length Short Hair (H) Long Hair (h)
Tabby Stripes Tabby (T) Stripeless (t)
Color point (markings on nose, ears, paws, and
tail)
Normal Color point
Sample Problem #6A heterozygous short haired cat is crossed with another heterozyogous cat cat. What are the expected genotypes and phenotypes of their offspring?
Trait Number of Students Demonstr
at-ing Dominant
Phenotype
Number of Students Demonstr
at-ing
Recessive Phenotype
PercentageDemonstrat-
ingDominantPhenotype
PercentageDemonstrat-
ingRecessivePhenotype
Dominant Recessive
TongueRoller ( R )
Nonroller ( r )
Taster ( T )
Non-Taster ( t )
FreeEarlobes ( E )
AttachedEarlobes ( e )
Dimples ( D )
NoDimples ( d )
No 2nd joint finger hair
( F )
2nd joint finger Hair
( f )
Two Trait Cross
Mendel determined that alleles assort independently from each other, even when multiple traits are studied.
Phenotype= 9:3:3:1
Genotype = 1:2:1:2:4:2:1:2:1
The British Royal Family
Human traits are difficult to study for several reasons. Unlike some organisms, which produce slowly and only a few offspring at one time. Thus human traits must be studied through population sampling and pedigree analysis. A pedigree is a diagram that shows the phenotype of different generations.
Royal family tree
Pedigree for ColorBlindness – a sex linked trait