Slide 1 : Gregor Mendel (1822-1884) Father of genetics
Development of heredity
Father of Modern Genetics : Father of Modern Genetics The first person to trace the characteristics
of successive
generations of a living thing He was not a world-renowned scientist of his day.
Rather, he was an Augustinian monk who taught natural science to high school students.
Slide 3 : Second child of Anton and Rosine
Mendel
They were farmers in Brunn
They couldn’t afford for him to attend
college
Gregor Mendel then attended the
Augustinian Monastery and became a monk Family
Where Mendel Studied : Where Mendel Studied Where Mendel Studied He was later sent to the University of Vienna to study.
By both his professors at University
and his colleagues at the monastery,
Mendel was inspired to study variance in plants
Slide 5 : The Monastery Garden
with the greenhouse whichGregor J. Mendel, O.S.A.,
had built in 1870.
Its appearance before 1902.
Courtesy of Villanova
University Archives. Gregor J. Mendel, O.S.A.,
experimental garden
(35x7 meters)
in the grounds of the
Augustinian Monastery in Old Brno.
Its appearance before 1922.
Courtesy of Villanova
University Archives.
Slide 6 : How Mendel Got Started Mendel's attraction to research was based on his love of nature.
He was not only interested in plants, but also in meteorology and theories of evolution.
Mendel often wondered how plants obtained atypical characteristics.
Slide 7 : The Birth of the idea: Heredity On a walk around the monastery, he found an atypical variety of an ornamental plant.
He took it and planted it next to the typical variety.
He grew their progeny side by side to see if there would be any approximation of the traits passed on to the next generation.
This experiment was "designed to support or to illustrate Lamarck's views concerning the influence of environment upon plants.“
He found that the plants' respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment.
Mendel's research reflected his personality. : Mendel's research reflected his personality. Once he crossed peas and mice of different varieties "for the fun of the thing," and the phenomena of dominance and segregation "forced themselves upon notice."
He saw that the traits were inherited in certain numerical ratios. He then came up with the idea of dominance and segregation of genes and set out to test it in peas.
It took seven years to cross and score the plants to the thousand to prove the laws of inheritance!
Pictures of atypical plant : Pictures of atypical plant Mendel choose peas to study for several reasons.
Reproduced and grew quickly so that result could be obtained in a reasonable time.
Self and cross pollinated
Pea plant with several traits : Pea plant with several traits A distinguishing feature of the plant was that they displayed various traits that only occurred in two distinct variations , with no blending
experiments : experiments Mendel conducted experiments to answer one of the fundamental questions of heridity. What r the basic patterns in the transmission of traits from parents to offspring?in this re-creation of Mendel’s historic experiments u wil have the opportunity to predict the outcome of two types of genetic crosses using
a punnett square
Inheritance of single trait : Inheritance of single trait In this 1st exam. , the plants being mated differ in just one trait,one plant is homozygous for the dominant purple flower allele of a gene, the other is homozygous for a recessive white flower allele.
To show the mating we arrange plants along two sides of the square. Note that each parent produce a single type of gamete. Draw puneett square
Exercise one : Exercise one The genotype of each gamete produced by one parent is brought down into each square below it. Likewise, the genotype each gamete produced the other parent is moved into each square to the right. This square helps us predict the genotypes of the offspring. Draw square and using the information provided predict the phenotypes of the offspring.drag the correct phenotypes to each square in the grid.phenotype choices are-purple ,pink , white
Ex.-1 : Ex.-1
experiments : experiments Mendel conducted experiments to answer one of the fundamental questions of heridity. What r the basic patterns in the transmission of traits from parents to offspring?in this re-creation of Mendel’s historic experiments u wil have the opportunity to predict the outcome of two types of genetic crosses using
a punnett square
Experiment conclusion : Experiment conclusion The 1st series of crosses recaps the result of mating in which the parent plant differ in single trait .the parent plants are homozygous for the dominant and recessive alleles. But their f1 gen. are heterozygous and show the dominant purple type of phenotype.
The next gen ,called the f 2 reveals a typical 3:1 ratio of phentypes. The recessive phenotype reappears in this gen. after having disappeared in f one gen.
Inheritance of two traits : Inheritance of two traits The two series of crosses b/w the parent plants differ in two traits these traits are round vs wrinkled texture and yellow vs green color. Each croos yields a 3:1 ratio of phenotypes in the f 2 generation. If the two heterozygous f 1 gen. plants were crossed, what genotypes and phenotypes would result? Go for exercises-
In our cross, notice that all of the f 1 individuals show the dominant yellow and rond phenotypes. The recessive alleles in this generation are +ent, but dominant alleles mask the recessive phenotype. If we matef 1 individuals to each other or allow them to self poolinate, what kind of offspring would u expect? : In our cross, notice that all of the f 1 individuals show the dominant yellow and rond phenotypes. The recessive alleles in this generation are +ent, but dominant alleles mask the recessive phenotype. If we matef 1 individuals to each other or allow them to self poolinate, what kind of offspring would u expect?
Slide 19 : Parent Generation F1 Generation F2 Generation, 3:1 ratio
Law of segregation : Law of segregation
Mendel’s laws of heredity : Mendel’s laws of heredity From his studies, Mendel derived certain basic laws of heredity:
These laws were law of dominance, law of seggregation and law of independent assortment
Hereditary factors do not combine, but are passed intact;
Each member of the parental generation transmits only half of its hereditary factors to each offspring (with certain factors "dominant" over others);
Different offspring of the same parents receive different sets of hereditary factors.
conclusion : conclusion when the genes for two traits are considered, the f 2 plants have phenotypes in a ratio of 9:3:3:1
Nine round and yellow
Three round and green
Three wrinkled and yellow
One is wrinkled and green.
Regardless of the color phenotype, the ratio will always be 3:1 . Similarly regardless of the texture genotype, the color ratios will always be 3:1. these results are typical for traits that assort independently. The phenotype ratio of the f 2 gen. is typical of a cross in which the parental gen. Differs in two traits that assort independently of each other.
According to mendel’s law of independent assortment , the genes behave independently of each other during meiosis,resulting in this predictable rato of phenotypes in the offspring.
Slide 23 :
Slide 24 : YY GG YG YG YG YG Y= Yellow allele G= Green allele YY GG YG YG F1 Generation F2 Generation YY YY YY YY YY GG YG YG YY GG YG YG GG GG GG GG
Mendel's work became the foundation for modern genetics : Mendel's work became the foundation for modern genetics The impact of genetic theory is no longer questioned in anyone's mind.
Many diseases are known to be inherited
and pedigrees are typically traced to determine the probability of passing along an hereditary disease.
Plants are now designed in laboratories to exhibit desired characteristics.
The practical results of Mendel's research has not only changed the way we perceive the world, but also the way we live in it.
Slide 26 : Interesting Facts Took seven years to prove laws of inheritance
-Basic Laws-
Heredity Factors do not combine
Each member of a parental generation transfers only one half of its heredity factors to each offspring
Slide 27 : More Interesting Facts Mendel’s works became the foundation of modern genetics
Later crossed mice and pea plants
Noticed traits were inherited in certain numerical ratios
Came up with idea of dominance and segregation of genes and set out to test it in peas
Love of nature encouraged his interest in research
Also interested in meteorology and theories of evolution