Gregor Mendel was an Austrian monk who is considered the father of genetics. In the 1850s and 1860s, he cultivated and tested thousands of pea plant varieties, discovering the basic principles of heredity. He found that physical traits are inherited as discrete particles, later known as genes and chromosomes. Mendel's experiments with pea plants established the laws of inheritance, including that dominant traits will appear to "mask" recessive traits in the first filial generation, but recessive traits can reappear in subsequent generations. His work helped establish the field of genetics, though it was not widely recognized until the early 20th century.

1. By jawher Ali
8/1/2023 by jawher Ali

2. Gregor Mendel
(1822-1884)
The father of
Genetics
8/1/2023 by jawher Ali

3. Austrian monk
Studied the inheritance of traits in pea plants
Develop the laws of inheritance
Mendel’s work was not recognize until the
20th century
8/1/2023 by jawher Ali

4. Gregor johann Mendel
Between 1856 and
1863,Mendel
cultivated and tested
thousands of pea plant
He discovered how
heredity works-how
organisms transfer their
traits to the offspring.
8/1/2023 by jawher Ali

5. Particular inheritence
Mendel stated that
physical traits are
inherited as “particles”
Mendel did not know
that the “particles” were
actually chromosomes-DNA!
8/1/2023 by jawher Ali

6. Why peas, pisum sativum?
Why peas?
 produce lots of offspring
 Grow quickly
 Can be grown in a small area
 Can be artificially cross-pollinated
8/1/2023 by jawher Ali

7. Mendel and his peas
• Mendel tested 7 traits:
1.Flower colour
2.Flower position
3.Seed color
4.Seed shape
5.Pad shape
6.Pod color
7.Plant height
8/1/2023 by jawher Ali

8. Mendel and his peas
• He crossed a purple (pp) flowered plant
with a white (pp) flowered plant.
(parent Generation)
8/1/2023 by jawher Ali

9. Yes, copy the picture.
• The first
generation (F1) of
plant all had
purple flowers.
• Where did the white color
go??
8/1/2023 by jawher Ali

10. • Mendel crossed his first
generation (F1XF1)
PURPLE flowered plants
Together.
• In second
generation (F2) he had
3 purple flowered
plants, and 1 white
Flowered plant.
8/1/2023 by jawher Ali

11. 8/1/2023 by jawher Ali

12. Mendel and his peas
• Mendel noticed in the first generation, all of the
white flowers seemed to disappear
• He called this a recessive trait.
• The white color faded away,
and was not expressed physically.
• But - it showed up in the next generation!
8/1/2023 by jawher Ali

13. The purple that
overpowered the
recessive color was named
the dominant trait.
8/1/2023 by jawher Ali

14. Mendel and his peas
• Mendel found that each plant
carried two sets of instruction
for each characteristic(one from
the “mom” and one from “dad”).
• These sets of instruction are called
alleles. (remember the “Genetics
notes?”)
8/1/2023 by jawher Ali

15. vocabulary
- Heredity- the passing of traits from
parent to offspring.
- Homozygous - both alleles are identical.
also knows as True-breeding. Ex: PP or pp
- Heterozygous – each allele is different.
also know as hybrids. EX: Pp
8/1/2023 by jawher Ali

16. vocabulary
• P generation – the parent generation.
• First- generation or F1- the very first set of
offspring from two parents
• Second-generation or F2 – the offspring of
The kids from the F1 generation(grandkids)
• dominant trait- represented with a capital
letter, it overpowers the recessive trait.
8/1/2023 by jawher Ali

17. vocabulary
8/1/2023 by jawher Ali

18. Mendel’s Investigations
Mendel’s laws
1. Law of segregation
a. It state that there are two factors controlling
a given characteristic, one of which dominates
the other
b. These factors separate and go to different gametes
when a parent reproduces.
8/1/2023 by jawher Ali

19. Mendel’s Investigations
2. Law of independent assortment
a. It states that factors controlling different
characteristic are inherited independently of
each other.
8/1/2023 by jawher Ali

20. that’s All
Thank you
By jawher Ali
8/1/2023 by jawher Ali