Test: Kingdom Protista- 1 - JAMB MCQ

The cell walls construction of diatoms is known as Frustule which consists of two thin overlapping shells fitting into each other just as a soap-box. Their walls are made up of silica. When the diatoms die, the silica in their cell walls gets deposited in the form of diatomaceous earth. This diatomaceous earth is very soft and quite inert. It is used in filtration of oils, sugars, and for other industrial purposes.

Slime molds are placed under myxomycetes and are characterized by the presence of different morphology at different life stages. The vegetative stage of cellular slime molds is a haploid amoeboid cell and is known as pseudoplasmodium. Thus, the correct answer is D. 

Besides erythrocytes, the plasmodium attacks one more type of cells in our body this are hepatocytes (lever cells)

Mycelial, nitrogen-fixing, symbiotic bacteria in root nodules of non-leguminous plants is Frankia.
Rhizobium produces nitrogen fixing nodules in leguminous plants. But, Frankia also produces nitrogen-fixing nodules on the roots of non-leguminous plants (e.g. Alnus). Frankia is free-living in the soil, but can fix atmospheric nitogen as symbionts.

Paramecium is a unicellular organism with a shape resembling the sole of a shoe. It ranges from 50 to 300um in size which varies from species to species. It is mostly found in a freshwater environment. It is a single-celled eukaryote belonging to kingdom Protista and is a well-known genus of ciliate protozoa.

Diatoms are unicellular eukaryotes placed under kingdom Protista; they are the primary photosynthetic producers in marine food chains and store their food as oil and polysaccharide leucosine. Thus, the correct answer is option C.

• Euglenoids have a protein rich layer called pellicle which makes their body flexible.
• Euglenoids have two flagella that help in their movement.
• Euglena changes its body shape during its movement and this phenomenon called as metaboly is possible due to pellicle.

Diatoms are unicellular eukaryotes placed under kingdom Protista; option D is incorrect. Cell of Diatoms are surrounded by cell wall having two parts or frustules; frustules make two overlapping halves (the epitheca and the hypotheca). Presence of numerous tiny pores in frustules connects the protoplast of the cell with the outside environment; this makes option A incorrect as their wall are in contact with surrounding water through pores. The pectic substance of cell wall is richly impregnated with silica, which creates patterns of minute perforations and striations. Around 90 percent of diatomaceous cell wall is silica. Shells of diatoms are highly resistant to decomposition due to presence of silica and are deposited in ocean beds leading to formation of diatomaceous earth. This makes option B incorrect and option C correct. Thus, the correct answer is option C. 

Long classified together in the Myxomycophyta as part of the Fungi, slime "molds" are now known to be quite unrelated to the fungi. There are three main groups of slime molds, which do not form a clade. Plasmodial slime molds, like Physarum shown here, are basically enormous single cells with thousands of nuclei.

• Chrysophytes are found in aquatic habitats.
• They are present in fresh water as well as marine.
• Chrysophytes Are microscopic in nature and float in water currents like planktons.

Zooplankton belong to the KingdomProtista. This kingdom contains many unicellular organisms which do not fit into any other kingdom. Protists are classified as any organism which is not an animal, plant, or fungus. Although this kingdom contains mostly unicellular organisms, it can also contain some multicellular organisms which include algae. Members of this kingdom can be either heterotrophic or autotrophic.

Cells of diatoms are surrounded by the cell wall, deposited with silica called as frustules which are composed of two overlapping halves (the epitheca and the hypotheca). Shells of diatoms are highly resistant to decomposition due to the presence of silica and are deposited in ocean beds leading to the formation of the diatomaceous earth. This is used as filters because its silica content makes it chemically inactive and uncompressible during insulation.

Protozoa living in fresh water are subjected to a hypotonic environment. Water flows across their plasma membrane since their cytosol is always hypertonic to the environment. Many wall-less protozoa have an organelle, the contractile vacuole complex (CVC), that collects and expels excess water.

Because members of this class are exclusively endoparasites.

• Diatomaceous earth is used in pest control and grain storage.
• This is because they are abrasive in nature which snatches out lipids from the outermost layer of pests called cuticle and makes them dry which results in their death.

Sargassum, also called gulfweed or seaholly, genus of about 150 species of brown algae(family Sargassaceae) generally attached to rocks along coasts in temperate regions or occurring as pelagic (free-floating) algae in the open sea.

Diatoms

1. produce thin, delicate cell walls rich in silicon (found in glass)
2. Cell walls fit together like a box (the top is just slightly larger than the bottom
3. ​The shells of dead diatoms are mined and ground up to be used as an abrasive in toothpaste and scouring powders.

Euglenoids carry characters similar to both plants and animals. The presence of chloroplast and photoautotrophic mode of nutrition make them similar to plants but the absence of cell wall and holozoic heterotrophic mode of nutrition in absence of sunlight excludes them from kingdom Plantae and put under kingdom Animalia. 

Some examples of decomposer protists are oomycetes, chytrids, labyrinthulomycetes, molds, etc. Oomycetes are fungus-like protists and typically grow on dead animals. Slime molds are also fungus-like protists and are commonly found on rotting logs and compost.

Cells of Diatoms are surrounded by the cell wall, frustules, which has silica deposits. Shells of diatoms are highly resistant to decomposition due to the presence of silica and are deposited in ocean beds leading to the formation of the diatomaceous earth. Extraction, grounding, sieving and sinteration of diatomaceous earth obtain Kieselguhr which is used in filtration techniques. Thus, the correct answer is option A. 

• Red tide is the coloration of water due to very rapid multiplication of red dianoflagellates.
• Chemicals released due to this rapid growth are harmful for aquatic life.

Diverse nutritional habits ranging from autotrophic to obligate intracellular parasite; thus they can be autotrophs like plants, heterotrophs like animals and decomposers/saprotrophs like algae. They are classified on the basis of phylogenetic relationship based on rRNA sequences. Option B is correct. Prokaryotes are characterized by absence of true membrane bound nucleus and intracellular membranous structures; these characters differentiate them from eukaryotic organisms. Option A is incorrect. Plants are eukaryotic organisms with characteristic cell wall and autotrophic mode of nutrition. Option C is incorrect. Animals differ from plants by absence of cell wall and heterotrophic mode of nutrition. Option A is incorrect. Thus, the correct answer is option B.

Maximum nutritional diversity is shown by the members of kingdom - Monera. Some of them are autotrophic (e.g. photosynthetic autotrophic or chemosynthetic autotrophic) while the vast majority are heterotrophs (e.g., saprotrophic or parasitic). Ecologically, these may be producers or decomposers.

Cell of diatoms are surrounded by cell wall having two parts or frustules. The pectin substance of cell wall is richly impregnated (around 90%) with silica, which creates patterns of minute perforations and striations. Diatoms are the primary photosynthetic producers in marine food chains and store their food as oil, polysaccharide leucosin and chrysolaminarin.  

During asexual reproduction, each daughter cell inherits only one valve of frustules and makes the smaller one within it causing decrease in the average size of diatom cells with successive generations. After reduction in size to considerable limit, diatoms enter sexual phase wherein isogamous or anisogamous auxospores/gametes are produced that fuse to form zygote and increase the cell size back to the normal. 

Dinoflagellates are the bioluminescent algae. They have pigment luciferin, which is acted upon by the enzyme luciferase, causing the production of light without any heat that makes them glow in dark. 

• Diatoms are grouped under Chrysophytes.
• Chrysophytes comprise of golden algae, diatoms and plant like protists etc.
• It’s because of the golden-yellow color of the species they are named as Chrysophytes.

Cilia are mostly present in hundreds, projecting out of the holes of the pellicle since basal bodies of all cilia are linked to common kinetodesmata. They beat in the coordinated rhythmic manner to produce paddle stroke effect. Due to their occurrence all over the body, they perform the fastest locomotion i.e., 400-2000 micrometer/second. So, they are the most efficient organs of locomotion.

Noctiuca, the night light, is a colourless dinoflagellate which exhibits holozoic nutrition and exhibits bioluminescence. Dinoflagellates are characterized by presence of pigment luciferin which is acted upon by the enzyme luciferase causing production of light without any heat; the bioluminescence. Absence of armoured cell wall, a characteristic feature of dinoflagellates, and presence of pellicle make them a protozoan. Option C is correct. Euglena is a eugneloid; a unicellular biflagellated alga that exhibits eugneloid movement, presence of histone proteins makes it distinct from dinoflagellates. Option A is incorrect. Ceratium is a dinoflagellate with characterstic armoured cellulosic cell wall and typical golden brown color; option B is incorrect. Gonyaulax is a red dinoflagellates; option D is incorrect. Thus, the correct answer is option C.

Noctiluca belongs to order Dinoflagellata of class Mastigophora. They are large, peach shaped, colorless and have vacuolated cytoplasm. They are phosphorescent and reproduce by binary fission and spore formation.