Gregor Mendel conducted monohybrid cross experiments using tall and dwarf pea plants to study inheritance patterns. He found that crossing pure breeding tall and dwarf plants produced only tall offspring in the first generation, while self-pollination of those tall plants resulted in both tall and dwarf plants in the second generation. This foundational research led to the establishment of Mendel's laws of inheritance.

1. MENDEL’S MONOHYBRID
CROSS
JAYASREE P.S. M.Sc (zoo), M.Sc (psy) NET, M.Ed., M.Phil NET
ASSISTANT PROFESSOR IN Dr. MGR INSTITUTE OF SPECIAL
EDUCATION AND RESEARCH

2. MONOHYBRID CROSS

3. GREGOR JOHANN MENDEL (1822-1884)

4. GREGOR JOHANN MENDEL (1822-1884)
• Mendel was educated in a monastery and went
on to study science and mathematics at the
university of Vienna.
• Mendel blended his knowledge of science and
mathematics and was the first one to keep count
of individuals exhibiting a particular trait in each
generation. This helped him to arrive at the laws
of inheritance.

5. MENDEL’S MONOHYBRID CROSS
• Mendel selected tall and dwarf garden pea
plants, Pisum sativum for the experiments.

6. DOMINANT AND RECESSIVE TRAITS

7. MENDEL’S MONOHYBRID CROSS
• He observed their growth for nearly two years
and found that tall plants always produce tall
plants and dwarf plants produce dwarf plants –
generation after generation on self-pollination
and under natural conditions.

8. MENDEL’S MONOHYBRID CROSS
He termed those tall
and dwarf plants as
wild types or pure
breeding varieties.

9. MENDEL’S MONOHYBRID CROSS
.

10. MENDEL’S MONOHYBRID CROSS

11. MONOHYBRID CROSS
• He crossed a tall plant with a dwarf plant and observed
how the traits are transmitted the progeny and calculated
the percentage of tallness and dwarfness in subsequent
generations.
• When a pure breeding tall plant (TT) was crossed with a
pure breeding dwarf plant (tt), all plants were tall in the
first filial generation (F1).
• When such an F1 tall plant was allowed to self-pollination,
both the tall and dwarf plants were appered in the second
generation F2.

12. DIAGRAMMATIC REPRESENTATION
OF MONOHYBRID CROSS

13. CHECKER BOARD
CC

14. The first experiment of
Mendel considering the
inheritance of a single trait
(Height of the plant-
Tall/Dwarf) is called
monohybrid cross

15. ACTIVITY
Observe the plants in your locality which
show different characters for the
following traits. Count them and record
your findings. Examples:
COCONUT TALL DWARF
Bean Violet Flower White flower
Sugarcane White Stem Purple Stem

16. THANK YOU