25 short questions with answers, suitable for 2 to 3 marks each, based on the "Diversity in the Living World" chapter for CHSE Class 11.

1.What is biodiversity? Why is it important?

Answer: Biodiversity refers to the variety of life forms existing on Earth, including the diversity within species, between species, and of ecosystems. It is important for maintaining ecological balance, providing essential resources (food, medicine), and supporting ecosystem services.

2.Define binomial nomenclature. Give an example.

Answer: Binomial nomenclature is a system of naming organisms using two names: the genus name (first, capitalized) and the specific epithet or species name (second, lowercase). Both are usually italicized. Example: Homo sapiens (human).

3.What are the key differences between genus and species?

Answer: Genus is a group of related species sharing common characteristics. It is a higher taxonomic category than species. Species is the basic unit of classification, representing a group of individuals that can interbreed to produce fertile offspring.

4.List the seven obligate taxonomic categories in descending order.

Answer: The seven obligate taxonomic categories in descending order are: Kingdom, Phylum, Class, Order, Family, Genus, Species.

5.What are the main characteristics of the Kingdom Monera?

Answer: The main characteristics of Kingdom Monera are that they are prokaryotic organisms, typically unicellular, lack a well-defined nucleus and membrane-bound organelles, and exhibit diverse modes of nutrition.

6.How do protists differ from monerans?

Answer: Protists are eukaryotic organisms, meaning their cells have a true nucleus and membrane-bound organelles, while monerans are prokaryotic organisms lacking these features. Protists can be unicellular or multicellular, while monerans are primarily unicellular.

7.What are the distinguishing features of the Kingdom Fungi?

Answer: The distinguishing features of Kingdom Fungi include their eukaryotic organization, heterotrophic mode of nutrition (mostly saprophytic or parasitic), and cell walls made of chitin. They are mostly multicellular, except for yeasts.

8.Mention two key characteristics of the Kingdom Plantae.

Answer: Two key characteristics of the Kingdom Plantae are their eukaryotic organization with cell walls made of cellulose, and their autotrophic mode of nutrition due to the presence of chlorophyll for photosynthesis.

9.State two important features of the Kingdom Animalia.

Answer: Two important features of the Kingdom Animalia are their eukaryotic organization without cell walls, and their heterotrophic mode of nutrition (ingestion of food). They are typically multicellular and exhibit complex tissue and organ systems.

10.Why are viruses not included in the five-kingdom classification?

Answer: Viruses are not included in the five-kingdom classification because they are considered acellular. They lack the characteristics of living cells, such as metabolism and independent reproduction, and require a host cell to replicate.

11.What are the components of a virus?

Answer: A virus typically consists of a nucleic acid core (either DNA or RNA, but not both) enclosed within a protein coat called a capsid. Some viruses may also have an outer envelope derived from the host cell membrane. 1  

12.Differentiate between a viroid and a virus.

Answer: A viroid is an infectious agent composed only of a small, circular, single-stranded RNA molecule without a protein coat. A virus, on the other hand, consists of nucleic acid (DNA or RNA) enclosed in a protein coat (capsid).

13.Describe the symbiotic relationship in a lichen.

Answer: A lichen represents a symbiotic relationship between an alga (phycobiont) and a fungus (mycobiont). The alga provides food through photosynthesis, while the fungus provides shelter, water, and mineral absorption.

14.What is the role of the phycobiont and mycobiont in a lichen?

Answer: The phycobiont (algal component) in a lichen is autotrophic and produces food through photosynthesis. The mycobiont (fungal component) is heterotrophic and provides structure, protection from desiccation, and absorbs water and nutrients.

15.What is a herbarium? What is its significance?

Answer: A herbarium is a collection of dried and pressed plant specimens that are systematically arranged, labeled, and stored for scientific study. Its significance lies in providing a reference for plant identification, taxonomic research, and conservation efforts.

16.Define a zoological park. What is its purpose?

Answer: A zoological park is a facility where live animals are kept in enclosures that mimic their natural habitats for public exhibition, education, research, and conservation purposes.

17.What is a taxonomic key? How is it helpful in identification?

Answer: A taxonomic key is a tool used for the identification of organisms based on a series of contrasting characters arranged in pairs called couplets. By making choices between the contrasting characters (leads), one can progressively narrow down the identity of an organism.

18.Explain the concept of "lead" and "couplet" in a taxonomic key.

Answer: In a taxonomic key, a couplet consists of two contrasting statements or choices related to a particular character of an organism. Each statement in a couplet is called a lead. The user chooses the lead that best describes the organism being identified, leading to the next couplet or the identification.

19.Differentiate between flora and fauna.

Answer: Flora refers to all the plant species found in a particular region or habitat. Fauna refers to all the animal species found in a specific region or habitat.

20.What is a monograph? How is it different from a flora?

Answer: A monograph is a comprehensive taxonomic treatment of a single taxon (e.g., a genus, family, or order), providing detailed information about its classification, distribution, morphology, ecology, and evolution. A flora, on the other hand, is a description of the plant species found in a specific geographical area.

21.Define the term "taxon". Give an example of a taxon at the family level.

Answer: A taxon is a taxonomic group of any rank in the classification system. It represents a unit in the classification. Example of a taxon at the family level: Felidae (the cat family).

22.What are the defining properties of living organisms?

Answer: Defining properties of living organisms include metabolism (sum of all chemical reactions), growth (increase in mass and number), reproduction (producing offspring), consciousness (awareness and response to stimuli), and cellular organization. Metabolism and consciousness with cellular organization are considered truly defining.

23.Why is reproduction not considered a perfectly defining characteristic of living organisms?

Answer: Reproduction is not a perfectly defining characteristic because some living organisms, such as sterile worker bees, mules, and infertile human couples, do not reproduce. However, all living organisms reproduce (in some way or at some point), and non-living things do not.

24.Explain the significance of the International Code of Botanical Nomenclature (ICBN). Answer: The ICBN (now ICN) is a set of rules and recommendations governing the scientific naming of plants, algae, and fungi. Its significance lies in ensuring uniformity, stability, and universality in botanical nomenclature, preventing confusion caused by vernacular names and multiple scientific names.

25.Briefly explain the concept of biological species.

Answer: The biological species concept defines a species as a group of individuals that can interbreed in nature to produce fertile offspring and are reproductively isolated from other such groups. It emphasizes reproductive compatibility as the primary criterion for defining a species.