Question

Which type of body plan is present in Protozoa? PLEASE don't post irrelevant answers​

Answer 1

Answer:

General characters of protozoa

Protozoa are eukaryotic microorganisms. Although they are often studied in zoology courses, they are considered part of the microbial world because they are unicellular and microscopic. Protozoa are notable for their ability to move independently, a characteristic found in the majority of species.

Answer 2

Answer:

1. The animal-like protists are referred to as protozoans (>65,000 species).  What makes these animal like? (hint: what about energy metabolism and cell covering?).Thus all these are possible candidates for being the stem group from which multicellular animals arose.

• Protozoan are a very ancient group and hence display a diversity of characteristics:
• A variety of ways protozoa obtain energy:  heterotrophic consumption of organic carbon (holozoic or saprozoic) (though some are faculative phototrophs); some are predatory and some parasitic.

-------Parasites in general-------

• Overlooked in many fields of biology and medicine
• Extremely diverse (may outnumber the number of free-living species 4 to 1).  Highly specific and important to ecology of hosts
• Life cycles are often complex involving several vectors that may include reservoir and intermediate hosts

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• Protozoa usually reproduce asexually by binary fission. Some have sexual cycles, involving meiosis and the fusion of gametes or gametic nuclei often resulting in a thick-walled, resistant, and resting cell called a cyst.
• A variety of mechanisms for locomotion.  Flagella and cilia were previously thought to be important distinguishing characteristics determining evolutionary relationships among protists (and among animals).

  2. Cilia and Flagella (in eukaryotes be referred to as a single term, undulipodia)

• ATPase activity of dynein arm (similar to myosin) of microtubule bundle causes it to ratchets against the adjacent microtubule bundle (similar to actin) which causes cilia to bend.

• Fibers connect individual cilia below surface allowing for coordinated beating of cilia to move fluid over membrane (why?) and for locomotion (requiring a different 'recovery' stroke, why?).

• Remarkably similar throughout the protist, plant and animal kingdoms. Is this an important evolutionary clue in the origin of multicellular life?

• Why don't large multicellular animals use a large multicellular whip-like structure for locomotion?

  3. Pseudopodia  -Locomotion achieved by cytoplasmic streaming (transition between gel and more fluid sol somehow controlled by actin and maybe myosin fibers)