Page 26 - Genius Kidz Prudence Learning Sc-8

Protozoans as friend : multicellular alga, volvox. Flagellated

(i) They maintain the fertility of soil. algae include Chlamydomonas.
Tetraspore and non-flagellated include
(ii) They enhance the plant growth by making
Spirogyra.
ammonia and phosphates available to them.
(iii) They help in digestion of cellulose.

(iv) They are also effective in waste treatment
as they feed on fungi and bacteria.
Protozoa as a foe :

(i) Protozoans cause a number of animal and
human diseases. For example, malaria is Chlamydomonas Spirogyra
flagellated algae non-flagellated algae
caused by Plasmodium and Giardiasis is
caused by Giardia. (c) Size and Shape : Alage can range in size
from tiny microscopic form to giant
5. Algae (singular : Alga) : The study of algae is
algae such as kelp. Several different
called “phycology”. The term “alga” means
shapes of algae are as depicted in the
“sea weeds”. Algae are actually the plants with figure—rod like, spiral, club shaped, etc.
a cell wall and chlorophyll pigment in their
cells. They make their own food. They have no
roots, stem or leaves.

(a) Habitat : Algae are basically aquatic but
terrestrial (found on land), cryophytic
(present on ice and snow) and parasitic Chalmydomonas Volvox Ulothrix
algae are also found in nature.

(b) Structure : As already told, algae do not
have true differentiation into root, stem
or leaves and they may be mutlicellular
or unicellular. They may or may not
possess flagella. Example of unicellular Fristschiella Ulva Hydrodictyon

alga-Chlamydomonas and that of Different shapes and examples of algae

(d) Nutrition : Algae prepare their own food
with the help of chlorophyll, water and
sunlight. Thus, they are autotrophic in

nature.
(e) Reproduction : Algae can reproduce
both by sexual and asexual method.
Chlamydomonas-unicellular algae Multicellular algae-volvox

Cats cannot taste sweets.
!
Looking at the sun can trigger a sneeze.
!

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