Long day plants undergo flowering after receiving light above a critical day length. e.g. Spinach, sugarbeet. Short day plants flower only when they receive light below a critical day length. e.g. Glycine max, Tobacco.

Correct Option: D

Long day plants undergo flowering after receiving light above a critical day length. e.g. Spinach, sugarbeet. Short day plants flower only when they receive light below a critical day length. e.g. Glycine max, Tobacco.

It is due to Richmond-Lang effect. Cytokinins prevent degeneration of chlorophyll, proteins and nucleic acids. They increase of inflow of auxin and amino acids. It reactivates leaf metabolism.

Correct Option: D

It is due to Richmond-Lang effect. Cytokinins prevent degeneration of chlorophyll, proteins and nucleic acids. They increase of inflow of auxin and amino acids. It reactivates leaf metabolism.

Cytokinins help cells in retaining chlorophyll for longer time. Cytokinins delay the senescence (ageing) of leaves and other organs.

Correct Option: B

Cytokinins help cells in retaining chlorophyll for longer time. Cytokinins delay the senescence (ageing) of leaves and other organs.

Flowering is induced by light and temperature.

Correct Option: B

Flowering is induced by light and temperature.

Carrot is a biennial plant which flowers in the second season. Vernalization is the subjection of seeds or seedlings to low temperature in order to hasten plant development and flowering. Vernalization is commonly used for crop plants such as winter rye and is possible because the seeds and buds of many plants require cold in order to break dormancy. Winter cereals are therefore sown in the autumn for flowering the following year. However, if germinating seeds are artificially vernalized they can be sown in the spring for flowering the same year. Biennial plants, such as carrot (Daucus carota), will remain in their non - flowering rosette form until subjected to cold treatment.

Correct Option: C

Carrot is a biennial plant which flowers in the second season. Vernalization is the subjection of seeds or seedlings to low temperature in order to hasten plant development and flowering. Vernalization is commonly used for crop plants such as winter rye and is possible because the seeds and buds of many plants require cold in order to break dormancy. Winter cereals are therefore sown in the autumn for flowering the following year. However, if germinating seeds are artificially vernalized they can be sown in the spring for flowering the same year. Biennial plants, such as carrot (Daucus carota), will remain in their non - flowering rosette form until subjected to cold treatment.