Notes, Exercises, Videos, Tests and Things to Remember on Mendelian Experiment
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Let the genotypes for tall be TT and for dwarf tt.
First, the parent plants are cross pollinated to provide first filial generation (F1) and then F1 plants self-pollinated to give second filial generation (F2)
In first filial generation all the plants are tall (i.e. only dominant character is seen, but all plants are hybrid) then in second filial generation there are 3 tall and one short plant (Only phenotypically but genotypically the plant is one tall two-hybrid and one dwarf).
Genotypic ratio 1:2:1 (Dominant: Hybrid: Recessive) Phenotypic ratio 3:1 (Dominant: Recessive). Same goes for any other characters.
Let the two characters be shape of seed and color of seed and genotype be RRYY for pure round and yellow and rryy for pure wrinkled and green. Then these parent plants were first cross-pollinated to give F1 and then F1 were self-pollinated to give F2 generations. Ratio for the cross for second filial generation will be:
Round and yellow = 9 Round and green = 3 Wrinkled and yellow =3 Wrinkled and green = 1
On the basis of his experiments, Mendel came up with three conclusions on how characters behave when transmitted from generation to generation.
According to this law, when two plants one tall and another dwarf are cross-pollinated, only tall plants appears in first generation which is dominant:
This law states that when two pairs of independent allele (different characters) are brought together in the hybrid(F1), they, at the same time of gamete formation, assort independently and freely. This law is illustrated from dihybrid cross.
Law of segregation is directly related to the result to Mendel's mono hybrid experiment. This law states that the two contrasting genes or characters originally found in parents (male of female) are transmitted to the offspring but remains unexpressed until they come in contact with others.
Two application of Mendel's law of inheritance are as follows:
Mendel's laws are as follows:
In second filial generation there are ______.
All the answers are correct
3 short and 1 tall plant
3 tall and 1 short plant
all the plants are tall
The ratio of Genotypic is ______.
Variation may be defined as morphological or a physiological change in an organism due to the _______.
None of the answers are correct
Both genetic reason and physical reason