Question

The plants that live for more than two years are called:
A. Annuals
B. Perennials
C. Biennials
D. Triennials

Answer 1

A seed grows into a mature plant through a sequence of events. These events may occur within weeks in some plants to many years in some. On this basis of the variation of duration the life cycle of plants is classified into three types viz., annuals, biennials, or perennials. This classification of plants on such a basis is significant in terms of knowing about the various plants, mainly the plants that are of economical use to us, so they could be grown accordingly.

Complete answer: On the basis of the duration of life and growing season the plants are classified as-
i. Annuals- These plants complete their life cycle i.e., from germination of seeds to reproduction and then senescence within one growing season and then dies.
ii. Perennials- These are the plants that survive for more than two years. These are the small plants. Perennial plants are generally the plants with nonwoody stems that live for a shorter duration and these are the small flowering plants. These plants grow well in warmer climatic conditions.
iii. Biennials- Such plants complete their biological life cycle within two years.
iv. Triennials- These are the plants that require three years to complete their life cycle.
Additional information:
There are some plants that show unusual phenomena when it comes to their flowering period. Like a plant named Strobilanthes kunthiana (neelakurinji) this plant flowers once every 12 years. It is seen in the hills of Kerala, Karnataka, and Tamil Nadu.
Thus, the correct answer to this question would be option (B).

Note: The life cycle of a plant involves three phases-
a. Juvenile phase- This stage is the stage of growth and maturity, a period before an organism or a plant can reproduce sexually. This stage is called the vegetative stage in the case of plants.
b. Reproductive phase- This is the phase for reproduction, where a plant grows and reproduces to maintain their generation.
c. Senescent phase- This is the phase where a plant gets older and ultimately dies thus completing its life cycle.