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प्रश्न
Explain test cross with suitable example and state its ratios.
उत्तर
- A test cross is used to find out the genotype of any plant with dominant expression when it is not known whether it is homozygous (pure) or heterozygous for that trait.
- For example, a pea plant having purple flowers (F1 hybrid with unknown genotype) is crossed with a pea plant with white flowers (recessive).
- If all flowers produced are purple, we can conclude that plant is pure or homozygous and if we get purple and white flowers in a 1:1 ratio, conclude that plant is heterozygous.
- Following is the graphical representation for test cross:
- Assume that purple flower is Homozygous dominant (PP).
All flowers are purple. Thus, the F1 hybrid is homozygous dominant (PP). - Assume that purple flower is Heterozygous dominant (Pp).
Half of the flowers are purple and half are white. Thus, the F1 hybrid is heterozygous dominant (Pp).
APPEARS IN
संबंधित प्रश्न
Differentiate Between Genotype and Phenotype.
Complete the following sentence with appropriate word:
The physical expression of genes is called _________.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Mendel experimented upon plants of Oryza sativa.
Choose the Odd One Out
Multiple Choice Question
Genetics is a branch of biology dealing with:
Multiple Choice Question
When an individual has both the genes of a contrasting character, it is said to be:
Explain a dihybrid cross with suitable example and checker board method.
During a dihybrid cross with contrasting characters in the F2 generation, parental genotypes will appear in ______.
Mendel was successful in his experiments because:
A typical dihybrid cross is carried outbetween true breeding plant with yellowround seeds and a true breeding plant withgreen wrinkled seeds. With appropriatesymbol write the genotypes of —
- Homozygous dominant and recessive parents.
- Gametes produced by both the parents.
- Gametes produced by the F, hybrid. (3)
