Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

In a dihybird, cross, when would the proportion of parental gene combinations be much higher than non-parental types, as experimentally shown by Morgan and his group?

The phenotype of the F, hybrid resembles the dominant parent, when there is incomplete dominance. True/ False

Name any two types of cells which act as ‘Cellular barriers’ to provide Innate Immunity in humans.

Aa Bb was crossed with aa bb. What would be the phenotypic ratio of the progeny? Mention the term to denote this cross.

State the principle on which ELISA works.

Write the genotype of:

1. An individual who is carrier of sickle cell anaemia gene but apparently unaffected, and
2. An individual affected with the disease.

Name the two basic amino acids that provide positive charges to histone proteins.

Why have many animals not evolved thermo regulation?

Write an example of point mutation?

Write the equation that helps in deriving the net primary productivity of an ecosystem.

OR

How is the net primary productivity of an ecosystem derived?