CBSE Questions for Class 11 Medical Biology Biological Classification Quiz 4 - MCQExams.com

• The fungus is heteroecious, if it is parastic and requires two hosts for completion of its lifecycle.
• Most parasitic fungi are autoecious except rust, Puccinia which is heteroecious, as it requires two hosts for completion of its life cycle, i.e., wheat (primary host) and barberry (secondary host).
• On the other hand, an autoecious parasite completes its life cycle on a single host species. 

• Archaebacteria are primitive bacteria. 
• The cell wall is composed of glycolipids, amino acids and glycoproteins which form the S-layer. 
• There is no peptidoglycan present in the bacterial cell wall. 
• These organisms can survive in high salt concentration, high temperature, high pressure, etc. 
• They have genetically different 16S rRNA. 

• A clade is a grouping that includes a common ancestor and all the descendants of that ancestor. A key feature of a clade is that a common ancestor and all its descendants are part of the clade. 
• Cladograms emphasize the sequence or order in which derived characters arise from  the central phylogenetic tree and thus data for cladograms is present in the cladistics.
  
• Cladistics is now the most commonly used methods to classify organisms. 

• Cladistics is one of the three schools of systematics that determines the degree of relatedness by analysing the primitive and derived characters and constructs the cladogram.
  
• Cladistics is an approach to biological classification in which organisms are categorized in groups based on the most recent common ancestor. A key feature of a clade is that a common ancestor and all its descendants are part of the clade.
• In Cladistics  to show relations among organisms, cladogram is used. Cladistics is now the most commonly used methods to classify organisms.

• Viruses are acellular structure and are composed of rigid protein shell (capsid) surrounding nucleic acid (ss or ds RNA or DNA). 
• Viroids are the smaller infectious pathogens that consist of only nucleic acid and no protein coat. Thus, a virus without its protein coat is termed a viroid. 
• The complete, infective form of a virus outside a host cell, with a core of RNA or DNA and a capsid, is known as Virion.
• Integration of genome of temperate phage with that of host DNA leads to the formation of the provirus. 

• A lichen is a composite organism that emerges from algae living among the filaments (hyphae) of the fungi in a mutually beneficial symbiotic relationship.
• Fungi are Achlorophyllous organisms because they do not perform photosynthesis due to the absence of chlorophyll.
• Hence Lichens are composites consisting of algae and achlorophyllous organisms(fungi).
• So, the correct answer is 'Achlorophyllous organisms'.

• Diplanetism is a phenomenon having two mobile stages with a pause between them
• Saprolegnia release a zoospore that forms a cyst right away. This will germinate at some later time to release its secondary zoospore. 
• Hence Diplanetism is exhibited by Saprolegnia.
• So, the correct answer is 'Saprolegnia'.

Foliose lichen is the most complex lichen. It is a lichen with leafy body parts or thallus and which generally have a cortex on each side of the leafy lichen body part thallus. Crustose lichens are lichens that grow like a crust of paint on their substrate, and especially sqamulose crustose lichens, may not be attached to the substrate at the edges, giving a leafy appearance similar to foliose lichens, but there is no lower cortex on the leafy part. Fruticose lichens are lichens that have a form similar to a tiny leafless, branching shrub that may have the branches flattened, so as to appear leafy, but foliose lichens have a single cortex wrapping around the branches, whereas foliose lichens generally have an upper and a lower cortex. Gelatinous lichens may appear leafy, but lack a cortex or internal structure, having the photobiotic component diffuse throughout the no fruiting part of the lichen body, whereas in foliose lichens the algae are in a layer. In foliose lichens, the layer of tissue containing the photosynthetic component has the algae more diffuse in the fungus than in foliose lichens, where the algal layer is generally very distinct.

• Stemonitis is a distinctive genus of slime moulds which is found throughout the world (except Antarctica). 
• They are characterised by the tall brown sporangia supported on slender stalks, which grow in clusters on rotting wood.
•  In stemonitis, when the network is very fine, the transparent protoplasmic filaments is not obviously differentiated into endoplasm and ectoplasm in their initial stages of Plasmodium. This condition is called Aphanoplasmodium.
•  Hence,  Stemonites has Aphanoplasmodium types of Plasmodium.
• So, the correct answer is 'Aphanoplasmodium'.

Solution:

Correct answer is option A.
Explanation for correct option:

• Fungi differ from algae in having a chitin wall and they lack chlorophyll. Chitinous cell wall is a feature observed in Fungi.
• Algae have a cell wall made of glycoproteins and not chitin. Also, algae are autotrophs, while fungi are heterotrophic, saprophytic and even parasitic. 

• The Vorticella is a protist (protozoan) and belongs to the Phylum Ciliophora. 
•  It is a very interesting, stalked ciliate with an inverted bell shape. 
•  The stalk contains a contractile fibril called a myoneme. 
•  When stimulated, it shortens, causing the stalk to coil like a spring. 
• Hence, Bell - animalcule or pedicillate protozoan is Vorticella. 
• So, the correct answer is 'Vorticella'.

• Heterotrophic nutrition is a type of nutrition obtained by digesting organic compounds. It is common to both animals and fungi. 
• Fungus and animals are multicellular. 
• Chitin is present in arthropods and it is also present in fungus.