(a) Explain the different ways apomictic seeds can develop. Give an example of each.
(b) Mention one advantage of apomictic seeds to farmers.(c) Draw a labelled mature stage of a dicotyledonous embryo.
a. Different ways by which we can develop apomictic seeds include-
1. Formation of diploid egg i.e embryo without undergoing reduction division or fertilization e.gAsteraceae
2. Some nuclear cell divides surrounding the embryo sac divide continuously surrounding before protrude into embryo sac ultimately develop into embryo e.g Mango
b. Advantage of apomitic seeds for farmers include reduce cost of seed purchase, They can keep the hybrid seeds once purchases for next season.
(a) State the objective of animal breeding.
(b) List the importance and limitations of inbreeding. How can the limitations be overcome ?(c) Give an example of a new breed each of cattle and poultry
With advancements in genetics, molecular biology and tissue culture, new traits have been incorporated into crop plants. Explain the main steps in breeding a new genetic variety of a crop.
(a) Describe the various steps of Griffith’s experiment that led to the conclusion of the ‘Transforming Principle’.
(b) How did the chemical nature of the ‘Transforming Principle’ get established?
Describe how the lac operon operates, both in the presence and absence of an inducer in E.coli.