basic intro about the topic

1. Mendelian
Inheritance

2. Gregor Mendel
 Gregor Mendel, through his work on pea plants, discovered the fundamental
laws of inheritance.
 Gregor Mendel was a botanist, teacher, and Augustinian priest, the first person
to lay the mathematical foundation of the science of genetics, in what came to
be called Mendelism.
 Mendel chose to conduct his studies with the edible pea (Pisum sativum).

3.  He was born in 1822, and at 21, he joined a monastery in Brünn (now in the
Czech Republic).
 The monastery had a botanical garden and library and was a centre for science,
religion and culture.
 In 1856, Mendel began a series of experiments at the monastery to find out
how traits are passed from generation to generation.
 From 1854 to 1856, he tested 34 varieties for constancy of their traits.

5. Genetic Terminology
 Trait ; A trait, as related to genetics, is a specific characteristic of an
individual. Traits can be determined by genes, environmental factors or by a
combination of both. Traits can be qualitative (such as eye color) or
quantitative (such as height or blood pressure).
 Monohybrid cross; A monohybrid cross is defined as the cross happening in
the F1 generation offspring of parents differing in one trait only.
 Dihybrid cross; A dihybrid cross is a cross of F1 generation offsprings,
differing in two traits.

6.  Allele; An allele is one of two or more versions of DNA sequence (a single
base or a segment of bases) at a given genomic location.
 Genotype; The genetic constitution of an individual organism.
 Phenotype; Phenotype refers to an individual's observable traits, such as
height, eye color and blood type. A person's phenotype is determined by both
their genomic makeup (genotype) and environmental factors.
 Homozygous; having two identical alleles of a particular gene or genes.
 Heterozygous; having two different alleles of a particular gene or genes.
 Genotype RR Rr rr
 Phenotype Red Red yellow

7. Punnett Square
 The Punnett square is a square diagram that is used to predict the genotypes of a
particular cross or breeding experiment.

8. Why Pea?
 He chose peas because they had been used for similar studies, are easy to grow
and can be sown each year.
 Pea flowers contain both male and female parts, called stamen and stigma, and
usually self-pollinate.
 Self-pollination happens before the flowers open, so progeny are produced
from a single plant.
 Pea plant has shortest life cycle.

9. Mendel’s Experiment Method
 Mendel was interested in the offspring of two different parent plants, so he had
to prevent self-pollination.
 He removed the anthers from the flowers of some of the plants in his
experiments.
 Then he pollinated them with pollen from other parent plants of his choice.

10. Mendel’s Law of Dominance
 Mendel's law of dominance states that: “When parents with pure,
contrasting traits are crossed together, only one form of trait appears in
the next generation.
 The hybrid offspring's will exhibit only the dominant trait in the phenotype.
 Law of dominance is known as the first law of inheritance.

12. Mendel’s Law of Segregation
 The law of segregation states that each individual that is a diploid has a pair
of alleles (copy) for a particular trait. Each parent passes an allele at random
to their offspring resulting in a diploid organism. The allele that contains the
dominant trait determines the phenotype of the offspring.

13. Monohybrid Cross
 The cross between two monohybrid traits (TT and tt) is called a Monohybrid
Cross. Monohybrid cross is responsible for the inheritance of one gene.

14. Mendel’s Law of Independent Assortment
 Mendel's law of independent assortment states that the alleles of two (or
more) different genes get sorted into gametes independently of one
another. In other words, the allele a gamete receives for one gene does not
influence the allele received for another gene.

15. Dihybrid Cross
 A dihybrid cross describes a
mating experiment between
two organisms that are
identically hybrid for two traits.
 A hybrid organism is one that is
heterozygous, which means
that is carries two different alleles
at a particular genetic position, or locus.

16. Test Cross
 The test cross is another fundamental tool devised by Gregor Mendel.
 In its simplest form, a test cross is an experimental cross of an individual
organism of dominant phenotype but unknown genotype and an organism with
a homozygous recessive genotype (and phenotype).
 A test cross is an experiment that is used to find out the genotype of a dominant
plant of the F2 generation.
 It is performed by crossing the dominant offspring with the homozygous
recessive parent. A tall plant (unknown genotype) is crossed with a dwarf plant
(known genotype).

18. Back Cross
 The mating of a hybrid organism (offspring of genetically unlike parents) with
one of its parents or with an organism genetically similar to the parent.
 The backcross is useful in genetics studies for isolating (separating out) certain
characteristics in a related group of animals or plants.
 The purpose of a backcross is to recover elite genotypes and to produce
offspring that are genetically similar or closer to parents.

19. Complete Dominance
 Complete dominance is a form of dominance wherein the dominant allele
completely masks the effect of the recessive allele in heterozygous
conditions. A gene (or allele) shows dominance when it suppresses the
expression — or dominates the effects — of the recessive gene (or allele).
 An example of a simple phenotype, is flower color in Mendel's peas. One
allele as a homozygote produces purple flowers, while the other allele as a
homozygote produces white flowers.

20. Incomplete Dominance
 Incomplete dominance is a form of Gene interaction in which both alleles of a
gene at a locus are partially expressed, often resulting in an intermediate or
different phenotype. It is also known as partial dominance.

21. Codominance
 Codominance, as it relates to genetics, refers to a type of inheritance in which
two versions (alleles) of the same gene are expressed separately to yield
different traits in an individual.

22. THAN