group is made up of
and Filamentous algae.
simplest protist is
IS AN AMOEBA?
is a simple animal made up of just one cell.
lives in ponds, ditches or slowly moving streams.
is just visible to the naked eye.
respires, digests food and excretes waste.
about, responds to stimuli, grows, is able to repair and reproduces.
DOES AN AMOEBA FEED?
of the amoeba is the mud and water of ponds and ditches. In the
mud, there are many microscopic plants known as desmids.
When the protoplasm of the amoeba comes into contact with one
of these plants, it flows round the plant, forming a cup shaped
projection. This is literally a food cup, which completely encloses
and ingests the food. In this way a food-vacuole is formed in
the endoplasm. An amoeba, however, does not feed entirely on plants
it is also carnivorous feeding on tiny ciliates.
In the food vacuole, digestion commences and affected by similar
processes to higher animals. Enzymes are secreted into the food
vacuoles along with other digestive juices. The digested material
is now in a solution that can be absorbed into the surrounding
cytoplasm. Once all the digestible material has been absorbed
the remainder is excreted by the animal.
DOES AN AMOEBA RESPIRE?
simple animals and their whole surface is in contact with the
water that surrounds them and which contains oxygen.
oxygen the amoeba needs passes through the outer surface inwards
and carbon-dioxide which is a waste product, seeps outwards.
place by simple diffusion. As the amoeba uses up oxygen on the
inside, the concentrate of oxygen lowers, so there is less on
the inside than in the water outside.
then passes from the outer to the deeper parts of the protoplasm.
All living things need nutrition to provide energy and the protist
kingdom is no exception.
If we look at the amoeba, it gives us an example of a simple free