Botany lecture notes

Life Cycle in Algae (Haplontic, Diplontic, Haplodiplontic, Haplobiontic and Haplo-diplobiontic Life Cycles)

Life Cycle of Algae

Nature is a machine. The family is a machine. The life cycle is like a machine.

Ray Dalio

What is life cycle?

The growth and development consists of a number of distinct morphological and cytological stages. The sequence of these orderly changes is called as LIFE CYCLE. It is the sequence of all different phases or events through which an organism passes from a diploid zygote of one generation to the zygote of the next generation through haploid gametes.

There are five different types of life cycles in algae based on the number of haploid and diploid generations.

life cycle in algae

Haplontic Life Cycle

1. Haplontic life cycle

2. Diplontic life cycle

3. Haplodiplontic life cycle

4. Haplobiontic life cycle

5. Haplo-diplobiontic life cycle

(1). Haplontic life cycle:

Ø  Most common type of life cycle in algae

Ø  Life cycle is diphasic (two phases)

Ø  The prominent phase is haploid gametophytic phase

Ø  The diploid (sporophytic) phase in the life cycle is represented by the ZYGOTEContinue reading