Studying
Monohybrid Cross
1.1.
Goal
f
f
1.2.
Basic Theories.
Mendel’s
Laws, principles of
hereditary transmission of physical characteristics. They were formulated in
1865 by the Augustinian monk Gregor Johann Mendel. Experimenting with seven
contrasting characteristics of pure-breeding garden peas, Mendel discovered
that by crossing tall and dwarf parents, for example, he got hybrid offspring
that resembled the tall parent rather than being a medium-height blend. To
explain this he conceived of hereditary units, now called genes, which often
expressed dominant or recessive characteristics. Formulating his first
principle (the law of segregation), Mendel stated that genes normally occur in
pairs in the ordinary body cells, but segregate in the formation of sex cells
(eggs or sperm), each member of the pair becoming part of the separate sex
cell. When egg and sperm unite, forming a gene pair, the dominant gene
(tallness) masks the recessive gene (shortness).
Microsoft ® Encarta ® 2009. © 1993-2008
Microsoft Corporation. All rights reserved.
1.3.
Tools and Materials
a.
Tools
j White buttons 200 pieces
j Red buttons 200 pieces
j Two glasses of jars
b.
Materials
b
….
b
….
b
….
b
….
1.4.
Working Procedure
1.
In each jars, put 100 red buttons and 100 white
buttons. The two jars represent two individuals in F, generations in a
experiment. Red buttons represent dominant allele for round pea seed (B) and
white buttons for recessive wrinkled pea seed allele (b). Shake each jar to mix
the buttons.
2.
Put your left hand to one jar and the right one to
the other jar. Take a button from each jar at the same time randomly (avoid
looking at the inside of the jar). Put the two buttons on the tables (they represent zygote).
Record whether the result is red-red, red-white, or white-white
buttons.
3.
Repeat this process 3 times.
Write down
the working procedure explained by video in the column below !
1.5.
Attachment …
Note
f
Simbol
GENOTIP B, FENOTIP Bulat
f
Simbol
GENOTIP b, FENOTIP Kisut
f
Hasil
Perkawinan
1.6.
Observation Result
1.7.
Questions
å
How
the genotype ratio of the cross ?
å
How
the phenotype ratio of the cross?
å
What
conclusions can you draw from this experiment?
