Mendel's Experiments - Biographical information, Pea experiments

1. MENDELIAN GENETICS
By,
Dr. Nathiya T
Assistant professor
Department of Life Sciences
KJC, Bangalore

2. Mendel's Experiments - Biographical information,
Pea experiments

4. Mendel's Experiments - Biographical information
 Gregor Mendel (1822-1884) was an Austrian monk and
scientist who is considered the father of modern genetics. Here
are some key points about his biographical information:
 Mendel was born on July 20, 1822, in Heinzendorf, Austria
(now part of the Czech Republic)
 He grew up on a farm and developed an early interest in nature
and biology
 In 1843, Mendel entered the Augustinian Abbey of St. Thomas
in Brno, Czech Republic, where he later conducted his
experiments on inheritance
 He was ordained as a priest in 1847 and took on the name
Gregor.

5.  While in the monastery, Mendel taught physics, botany, and natural
history
 Mendel conducted his groundbreaking experiments on pea plants
between 1856 and 1863
 His experiments involved careful cross-breeding and observation of
traits in pea plants
 Mendel chose pea plants because they were easy to cultivate, had a
short generation time, and exhibited distinct and easily identifiable
traits
 He studied traits such as flower color, seed texture, seed color, pod
shape, and plant height
Contd…

6.  Mendel's work on pea plants laid the foundation for the field of
genetics and provided insights into the laws of inheritance
 Despite his significant contributions, Mendel's work went largely
unrecognized during his lifetime, and it was only after his death that
his research gained recognition and significance
 Mendel's experiments were rediscovered and appreciated by
scientists in the early 20th century, leading to the establishment of
Mendelian genetics as a fundamental principle in the field of biology
 Mendel's contributions to genetics revolutionized our understanding
of inheritance and paved the way for modern genetics and the study
of heredity
 His work continues to be a cornerstone of genetics and remains
highly influential in the field to this day
Contd…

7. Here are some key points about Gregor Mendel's
experiments with pea plants:
 Mendel conducted his experiments on pea plants
between 1856 and 1863 at the Augustinian Abbey
of St. Thomas in Brno, Czech Republic
 He chose pea plants (Pisum sativum) as his
experimental organism because they were easy to
grow, had a short generation time, and exhibited
distinct and easily observable traits
 Mendel worked with different traits of the pea
plants, including flower color, seed texture, seed
color, pod shape, and plant height
Pea experiments

8.  To conduct his experiments, Mendel carefully cross-pollinated pea
plants with specific traits, controlling the parental plants used in
each cross
 He observed the traits of the offspring (F1 generation) and
subsequent generations (F2 generation) resulting from these crosses
 Mendel focused on traits that exhibited clear-cut differences, such
as yellow versus green seed color or purple versus white flower
color
 He meticulously recorded and counted the number of individuals
showing each trait in the offspring generations
 Mendel noticed consistent patterns in the distribution of traits
across the generations and used statistical analysis to interpret his
results
Contd…

9.  From his experiments, Mendel derived three fundamental principles known as Mendel's Laws or
Mendelian inheritance:
 Law of Segregation: Each individual carries two alleles (alternative forms of a gene) for a trait,
and these alleles segregate or separate during gamete formation, with each gamete receiving only
one allele for a trait

10.  Law of Independent Assortment: Different traits are inherited independently of one another, as
the segregation of alleles for one trait does not influence the segregation of alleles for another trait

11.  Mendel's experiments and his formulation of these
laws provided evidence for the existence of discrete
units of inheritance (now known as genes) and laid
the foundation for our understanding of genetic
inheritance
 Although Mendel's work went unnoticed during his
lifetime, his discoveries were later recognized and
appreciated in the early 20th century, leading to the
development of the field of genetics
 Law of Dominance: Some alleles are dominant and mask the expression of other alleles
(recessive) when present together in an individual

12.  These postulates summarize Mendel's observations and deductions from his experiments
with pea plants

 They provided a foundation for understanding the principles of genetic inheritance and
helped explain the patterns he observed in the transmission of traits from one generation
to the next
 It is important to note that while Mendel's postulates accurately describe the inheritance
patterns for many traits, they do not account for certain complexities in genetics, such as
incomplete dominance, codominance, multiple alleles, and gene interactions
 Nonetheless, Mendel's postulates remain fundamental in genetics and provided the basis
for further advancements in the field
Contd…

13. Thank You