Why does it no longer seem correct to group all protists in a single kingdom?

Why does it no longer seem correct to group all protists in a single kingdom?

Why is “Kingdom Protista” no longer a valid taxonomic grouping? Protists include all eukaryotes except the clades Planta, Animalia and Fungi. Since all of these organisms are presumed to share a common ancestor, protists as a group would not include all of its descendents thereby making the grouping paraphyletic.

Why is it difficult to give very strict characteristics for protists?

Give two reasons why protists are difficult to classify. Most protists are single celled like bacteria, but protist are eukaryotic and have membrane bound organelles. Bacteria and archaea are single-celled, but their lack of a nucleus makes them prokaryotic and they lack membrane bound organelles.

Why are protists not considered a monophyletic group?

Why? “ ‘Kingdom Protista’ is not monophyletic; it contains organisms which are more closely related to members of other kingdoms than they are to other protists. All protists have one or more nuclei as well as other cell structures associated with multicellular life (cell membrane, vacuoles, ribosomes, etc.).

Why protists are considered to be Polyphyletic?

The protists are considered the polyphyletic organisms as they possess characteristics of the eukaryotic plants and animals but looking into the evolutionary history they do not share any immediate common ancestor. Thus, protists are considered polyphyletic organisms.

Are protists classified on the basis of being single celled or multicellular give an example to support your answer?

Protists are mostly unicellular (one-celled) eukaryotes. A few protists are multicellular (many-celled) and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long (Figure below).

What is the most compelling reason why protists are not considered to be a taxonomic group?

Viruses show no evidence of evolution. What is the most compelling reason why “protists” are not considered to be a taxonomic group? A. They are not cellular life forms.

What characteristic is used to place a protist into its informal group within the protist kingdom?

Protists are eukaryotes, which means their cells have a nucleus and other membrane-bound organelles. Most, but not all, protists are single-celled. Other than these features, they have very little in common. You can think about protists as all eukaryotic organisms that are neither animals, nor plants, nor fungi.

Why are protist considered to be part of a paraphyletic group rather than a monophyletic group?

Protists constitute a paraphyletic taxon since the latter is based on the plesiomorphic character of unicellularity and does not contain all descendants of the stem species.

Is the Euglena a member of the Protista group?

Short answer: The Euglena, as an eukaryotic single-celled organism, belong to the Protista. However, protista is not natural scientifically recognised group! It is an arbitrary group without an objective meaning in nature, from the evolutionary point of view. Long answer:

What kind of cell wall does an euglenoid have?

(i) Euglenoids are unicellular flagellate protists. They are without cellulose cell wall. The body is covered by thin and flexible pellicle (= periplast). The pellicle has oblique but parallel stripes called myonemes.

How are Euglena cells held together by collagen?

Animals are multicellular organisms held together by a specific protein called collagen. Euglena is single-celled, and the cell is enclosed in a semi-rigid protein sheath, not a true cell wall but not a simple cell membrane.

How does an Euglena feed like a plant?

Answer 2: Most species of Euglena have photosynthesizing chloroplasts within the body of the cell, which enable them to feed by autotrophy (making energy-containing organic molecules from inorganic raw material through the use of an energy source such as sunlight), like plants.