Spirogyra can easily be found in fresh water, in slow flowing streams.

A. Structure

-It is made up of unbranch filament; this filaments are made up of rows of single symmetrical cells. The cells are covered by a gelatinous sheath which is called the mucilage which provides protection to the cell. They posses are spiral chloroplast bearing pyrenoids called starch

-The dominant photosynthetic pigments are chlorophyll a and b

-Caroteroids and xanthophylls are also present in large quantities

-Each cells has a center nucleous supported by strands of the cytoplasm

-They have a large vacuole which is line by a thick lager of cytoplasm

-It poses a cellulose cell wall.

B. Mode of life of Spirogyra:

Feeding

They use their chlorophyll to manufacture starch by the process of photosynthesis; the starch is store in the pyrenoids.

Reproductions

Spirogyra reproduces in two ways: asexually by fragmentation

Here the filaments break up into fragment and each fragment continuous to grow by mitosis, it also undergo sexual reproduction by conjugation.

During conjugation, two identical filaments come together and live side by side. The filaments are hold together; one filament would contain the male gamete and the adjacent filament the female gamete. Since the filament look alike they usually designated positive for male gamete and negative for female gamete

The point of contact between the two filaments will form a conjugation tube which linked the two adjacent cells; the male gamete will migrate through the conjugation tube and fuse with the female gamete leading to the formation of a zygote. Since the gametes are identical the fusion is known as isogamous conjugation

The zygotes formed a thick pigmented protective wall round it and it becomes the zygospore. The zygospore is a resistant formed which helps the spirogyra to bypass advest condition when places become wet the nucleous the zygospore undergoes meosis to produce 4 daughter cells. Three of which degenerates the non haploid cell will divide by mitosis to formed a fresh filament (this is the germination of the zygospore)

Ecological Relationship of Spirogyra with other organisms

-When spirogyra carries out photosynthesis it picks up carbon dioxide from it surrounding. There by reducing the level of co₂ in the ponds and so preventing suffocation of organism in the ponds.

-The by-product of photosynthesis that is oxygen, oxygenates the ponds for the respiration of the pond organisms

Economic importance of spirogyra

-He carries out carbon fixation

-He is a producer in the food chain, therefore a source of single cell protein for human and animal consumption

Classification of spirogyra

Kingdom: Protoctista

Sub-kingdom: Algae

Phylum: Chlorophyta

Class: Chlorophyceal

Scientific name: Spirogyra jagensis

Common name: Spirogyra