Why are farmers and gardeners advised to buy new `F_1` hybrid seeds every year ?

Questions based on paragraph A geneticist made a cross between two pea plants having axillary flowers (AA) and round shaped seeds (RR) with plants having terminal flowers (aa) and wrinkled seeds (rr). In F_1 generation, he obtained plants with axillary flowers and round shaped seeds. But in F_2 generation, he obtained new combinations along with parental combinations. Which new combinations would be formed in F_2 apart from the parental combination?

Questions based on paragraph A geneticist made a cross between two pea plants having axillary flowers (AA) and round shaped seeds (RR) with plants having terminal flowers (aa) and wrinkled seeds (rr). In F_1 generation, he obtained plants with axillary flowers and round shaped seeds. But in F_2 generation, he obtained new combinations along with parental combinations. Write the gametes formed by the individual in F_1 generation.

A cross between a homozygous pea plant with a dominant character and a homozygous pea plant with a recessive character showed F_1 hybrids expressing the dominant character only. Which law of Mendel's applicable to the above statement?

Metals get attacked by substances around it such as moisture, acids, etc. Metal is said to 'corrode' due to this attack and the process is called corrosion. Many metals like iron, copper, silver, etc. get corroded. When iron is exposed to moist air, it undergoes corrosion and a reddish brown coloured solid layer is formed on its surface. Corrosion of iron, which is known as rusting, is a serious problem as enormous amount of money is spent every year to replace damaged iron. Similarly, copper reacts with moisture and. CO_(2) in air to form a green coloured coating of basic copper carbonate on its surface. Silver acquires a black colour when exposed to air containing H_(2)S due to the formation of silver sulphide on its surface. Based on the above paragraph, answer the following question. Why do we apply paint on iron articles?