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I edited your answer and I will delete this comment string shortly. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. Featured on Meta. This is a type of pseudopod strengthened by tiny microtubules that extend into solid protective rods. Some marine heliozoans radiolarians have a protective exoskeleton of silica, but freshwater species just have tiny silica scales or a perforated capsule.
All five groups of protozoans include some sessile species but most are swimmers. Ciliates use their many tiny cilia, in controlled waves, to propel themselves through the water. Flagellates have a single posterior flagella that pushes them forward in much the same way as a motor boat uses its propeller.
Amoebas locomote by shifting cytoplasm inside their bodies to create pseudopods that slowly pull the organisms along. Finally, heliozoans combine the efforts of cilia and axopods to maneuver their way through the water.
All protozoans have chemical or tactile senses to detect other members of their own species for sexual reproduction, but many of these chemicals have not yet been studied in detail.
A sensory structure has been identified in ciliates. Kineties found beneath the surface of the cell membrane at the base of each cilia , organized in a brushlike formation at the mouth, are used for prey recognition. Because they are so tiny, protozoans do not need any specialized organelle, such as red blood cells, to meet their oxygen demand.
In fact, many can live in water with very low concentrations of oxygen. Some ciliates have specially adapted green algae living inside them. In higher light conditions, these algae convert the carbon dioxide produced by the ciliate into oxygen, ensuring an abundant internal supply of oxygen for the ciliate. On the flip side, a few groups are anaerobic and intolerant of oxygenated water. These organisms are often endosymbionts living in the digestive system of multi-celled animals.
Protists use contractile vacuoles to remove excess water from their cells. If the contractile function of a cell is compromised, the cell swells until it ruptures. The same will also happen to a marine protozoan when placed in fresh water; marine members have no contractile vacuoles.
Ciliates have permanent contractile vacuole pathways and pores where amoebas will release them from any point along the surface of its body. Many protozoans reproduce both asexually and sexually during their lifetime. The move to sex is often either controlled by an internal clock or by the arrival of harsh environmental conditions. The majority of protozoans reproduce asexually by binary fission.
However, some are endosymbionts species that live within another organism that often engage in multiple fission with many tiny cells produced from a single parent cell released to search out a new host.
Sexual reproduction is common in ciliates, but rare in heliozoans and amoebas, and absent in flagellates. What kind of bacterium cannot tolerate oxygen. In what cycle of viral replication does the virus destroy the host cell. How is yeast used. What are the five main groups of arthropods. What do Amoebas use for movement. How are algae different from plants. How do cells control osmosis.
What is cytoplasm. Where is ATP often produced. What causes water to be a polar molecule. Q: What is the difference between protista and protoctista? Write your answer Related questions. Why protista are called protoctista? Common name of kingdom protista?
What is the difference between monera and protoctista? Algae is classified in what kingdom? The difference between the kingdom Monera and the kingdom Protista?
How can you tell the difference between fungi bacteria protista? What phylum and kingdom do paramecium belong? What types of organisms are unicellular? What is protoctista? What is the difference between kingdom monera and kingdom protista? What are the characteristics of kingdom protoctista? What is the Protoctista classification? Do protoctista have chloroplasts? What is the kingdom classification of euglenophyta? What are living things composed of more than 1 cell? What are the clear difrerences between kingdom protista and kingdom protozoa?
Why is kingdom protoctista difficult to classify what is the basis of their grouping in kingdom protoctista give example of each of its group?
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