Question

please help me out guys.. with question no. 5 only..​

Answer 1

AnswEr :

Height of a plant is a phenotypic trait and can be TT,Tt or tt depending upon the combination of genes.

• TT : Tall
• Tt : Hybrid Tall
• tt : Short

Consider two pea plants (Pisum sativum),one tall(TT) and one short (tt) as the parental generation.

Now, crossing the plants would produce two hybrids with phenotypes Tt.

Here,

The two "Tt" plants produced constitute the F2 generation. Cross pollinating the plants would give us :

$\boxed{\begin{array}{|c|c|c|} \cline{1-3} & \sf T & \sf t \\ \cline{1-3} \sf T & \sf TT & \sf Tt \\ \cline{1-3} \sf t & \sf Tt & \sf tt \\ \cline{1-3} \end{array}}$

The phenotypic ratio is 1:2:1.

• Furthermore,Tallness being the dominant trait appears more often in the successive generations and recessive traits hardly show up.

• Dominance of a gene depends on climatic conditions.

For example,

Finches of Darwin are group of birds found in New Zealand. Their beak sizes reduced during a famine while they regained their beak sizes during abundance of food. Well,these changes are gradual and time taking.