Question

Algae and protozoans are loosely grouped together as protozoans and are different from plants because they lack certain characteristics of plants. Explain what differentiates algae from plants and two ways they are different from protozoans. Talk about algae being part of our environment and how algae may positively or negatively impact our health or the environment.

(Words to use in your answer: cell wall, cell membrane, chloroplast, plankton, single-cell, multicellular, red tide, toxins, agar, phytoplankton, reproduction, motility, nutrition, feeding strategies)

Answer 1

Plants are a large group of organisms having a separate kingdom for their own classification but algae which was once considered to be a sub-part of the plant kingdom is now differentiated from it on various levels. Plants are multicellular whereas algae are unicellular like the Chlorella & diatoms to multicellular counterparts like the giant kelp. Plants are highly vascular as compared to algae as they lack stomata, phloem and xylem. Although algae has chlorophyll but it lacks the plant like structures such as leaves, stems and roots. They are more capable than plants in terms of nutrition as plants are mainly photoautotrophic but algae are mostly phototrophic but there are some who are mixotrophic or some who obtain energy both from photosynthesis as well as from organic materials by osmotrophy, myzotrophy and phagotrophy.

two points where algae are different from protozoans are algae are more plant like in terms of nutrition as they can produce their own food and can be both multicellular and unicellular. On the other hand, protozoans are more similar to animals but are unicellular. Algae do possess cell walls mostly but protozoans donot have a cell wall. They derive their energy by intaking several organic molecules or minute organisms.

algae are harmful to living stock as they can change the colour of the waterbody as well as block the gills of the fishes and make it difficult to breathe. as a result the fishes die from this blockage and also from the depletion of oxygen in the waterbody. there are certain poisonous blue-green algae who contaminate and in a way kill the livestock who drink this contaminated water. they have a role in blocking photosynthesis and causing various diseases to tea and coffee plants one such disease being "red rust of tea".

algae has a vast usefulness to environment as well as to other living organisms. Algae are a rich source of food i.e the naturally growing seaweeds which offer vitamins like A, B1, B2, B6, niacin and C. they are iodine, potassium, iron, magnesium and calcium reserves. they are also marketed as nutritional supplements. In the age of increasing demands of fuels in order to support this never ending population there is a potential risk that our next generation won't be able to use the fossil fuels as we would ourselves run out of it. So there comes the saviour -The algal fuels. They hold the promise of reproducing more biomass per unit area per year. The problem of pollution can also be controlled using this organisms in the form of sewage treatment, absorption of fertilizers from the farm run-offs.

In a nutshell, Algae are both a boon and a bane to the society but the usefulness can be increased by million times if we make these wonderful organisms work in a strategic manner.