Gregor Mendel conducted experiments with pea plants in the mid-1800s that helped establish the basic principles of heredity. Through studying over 30,000 pea plants, Mendel determined that physical traits are passed from parents to offspring through discrete units of inheritance, now known as genes, located in DNA. His work disproved the prevailing blending theory of inheritance and showed that traits are inherited independently of one another. Mendel is considered the founder of the modern science of genetics.

1. HEREDITY AND DNA
THEORY OF HEREDITY
BY: SARAH SHARIF
EIMAN RANA
MYP-V (ARMSTRONG)

2. INTRODUCTION:
Gregor Johann Mendel:
• An Austro-German Monk
• Botanist/Scientist
• Mathematician
• Discovered basic principles of
heredity
• Experimented Pea plants for the
study of genetics
• “Father of Genetics”

3. GENETICS:
• The Study of Heredity.
• Study of how heritable traits are transmitted from
parents to offspring.
• Two hundred years ago, biologists did not
recognize that there was such a thing as 'heredity'.
By the 1830s, however, insights from medicine and
agriculture had indicated that something is passed
from generation to generation, creating the context
for the brilliant advances of Mendel.

4. THE BLENDING THEORY OF
INHERITANCE
• 19th century; biologists held to the idea
• Prior to the discovery of genetics
• Not a formalized scientific theory (a kind of hypothesis)
• States that: inheritance of traits from two parents produces offspring with
characteristics that are intermediate between those of the parents.
• Plants in Mendel’s garden didn’t obey blending theory (he questioned)
• Experimented 30,000 pea plants

5. HEREDITY THEORY:
• Many physical traits caused by DNA passed from one generation to the next.
• Some traits are dominant while some recessive
• A pure-breed pea plant line is a homozygote - 2 identical copies of the same
allele.
• A cross-breed pea plant is a heterozygote –2 different alleles.
During experiment, considered :
• Flower colour is purple or white
• Seed color is yellow or green
• Flower position and stem length.
• Seed shape is round or wrinkled
• Pod colour is yellow or green and pod
shape.
• Cross-breed hybrids and found that traits
were inherited independently of each other

6. INTERESTING FACTS:
• He worked as a gardener and studied beekeeping in his childhood.
• Despite attempting twice, he failed to become a certified teacher
• Green eye color is the rarest eye colour.
• Genetic similarity. People share 7% of genetic material with the E.coli
bacteria, 21% with worms, 90% with mice and 98% with chimpanzees.
• The full stop at the end of a sentence is the size of one thousand cell nuclei.