Detrimental effect of host plant on the biology of insect is known as…? (IFFCO 2022)

• A test cross is the most reliable method for determining the genotype (homozygous or heterozygous) of an individual for a particular trait. Here's why:
-Known Genotype: In a test cross, the individual with an unknown genotype is crossed with an individual that is homozygous recessive for the trait in question.
-Predictable Outcomes: The resulting offspring's phenotypes will directly reveal the unknown genotype of the parent.
-If all offspring show the dominant trait, the parent is homozygous dominant.
-If there's a mix of dominant and recessive traits in the offspring, the parent is heterozygous.

📌 Other Options Explanations:
-Back cross: Backcrossing is a breeding method that involves crossing a hybrid organism with one of its parents or an organism that is genetically similar to its parents.
-Self-fertilization: a reproductive process in which the gametes (sex cells) from the same individual fuse.

🔑Key Points:
-Test cross –
-It is a genetic cross of an organism with a dominant phenotype with an organism having recessive phenotype.
-It is performed in order to determine the unknown genotype of an organism.
-It helps us to know whether the dominant phenotype has a homozygous or heterozygous genotype.
-Homozygous – It is the condition in which the pair of alleles determining a phenotype is identical, either both dominant or both recessive.
-Heterozygous – It is the condition where 2 different types of alleles are present, one dominant and one recessive.
-Genotype – It is the allelic constitution of a gene determining a particular character.
-Phenotype – It is the expressed character.
-Mendel had chosen 7 traits for his experiments on garden pea, from which he observed these genetic crosses.
-Each of these traits had 2 distinct phenotypic characters – one dominant and one recessive.

✅Explanation:
-For example, let us take the trait of stem height with the phenotypes of tall and dwarf plants.
-The tall plants can be homozygous (TT) or heterozygous (Tt), while the dwarf plants are always homozygous recessive (tt).
-To determine the genotype of a tall plant, we would perform a test cross with a dwarf plant.

✏The test cross may have 2 outcomes:
-Case 1 – If the unknown tall plant is homozygous (TT), it would produce all tall plants (Tt).
-Case 2 – If the unknown tall plant is heterozygous (Tt), would produce tall : dwarf plants in 1:1 ratio.

🛑Additional Information:
-Back cross –
-It is the genetic cross between F1 generation and either of the parent.
-It is performed to obtain an offspring with more phenotypic similarity with its parents.