Worksheet Solutions: Biological Classification | Science for ACT PDF Download

Section A. Fill in the Blanks

Q1: The science of classifying living organisms is called _______________.
Ans: Taxonomy

Q2: The highest category of classification is called _______________.
Ans: Kingdom

Q3: The five-kingdom classification system was proposed by _______________.
Ans: R.H. Whittaker

Q4: Bacteria that can live in extreme conditions are called _______________.
Ans: Extremophiles

Q5: The process of classifying organisms based on their evolutionary history is known as _______________.
Ans: Phylogenetic Classification

Section B. Match the Column

Match the following terms with their correct descriptions:

Ans:

Section C. Multiple Choice Questions

Q1: Which of the following is not a characteristic of fungi?
(a) Autotrophic nutrition
(b) Non-motile
(c) Cell walls made of chitin
(d) Reproduction by spores
Ans: (a) Autotrophic nutrition

Q2: Which of the following is a prokaryotic organism?
(a) Fungi
(b) Bacteria
(c) Protista
(d) Plantae
Ans: (b) Bacteria

Q3: The five-kingdom classification system is based on:
(a) Only habitat
(b) Both structure and habitat
(c) Only cell structure
(d) Only evolutionary history
Ans: (b) Both structure and habitat

Q4: Which kingdom includes organisms that lack a true nucleus?
(a) Animalia
(b) Plantae
c) Monera
(d) Protista
Ans: (c) Monera

Q5: The process of photosynthesis occurs in which kingdom?
(a) Animalia
(b) Plantae
(c) Fungi
(d) Protista
Ans: (b) Plantae

Section D. Assertion Reasoning Questions

Q1: Assertion: Binomial nomenclature was introduced by Carolus Linnaeus.
Reason: Binomial nomenclature uses two names for naming organisms.
(a) Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.
(b) Both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true, but the Reason is false.
(d) Both Assertion and Reason are false.
Ans: (a) Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.

Q2: Assertion: Bacteria and Archaea belong to the same kingdom in the five-kingdom classification system.
Reason: They share similar cell wall composition.
(a) Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.
(b) Both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true, but the Reason is false.
(d) Both Assertion and Reason are false.
Ans: (c) Assertion is true, but the Reason is false.

Section E. Case Based Questions

Case 1: In a pond ecosystem, a student observed a small organism with a soft, segmented body and jointed appendages. The organism is found to be an excellent burrower in the mud. Identify the organism and explain its classification.
Solution: The organism is likely an Annelid, specifically an Earthworm. Annelids are characterized by their soft, segmented bodies and jointed appendages. They belong to the phylum Annelida.

Case 2: A scientist discovered a new microorganism with a unique cell wall composition of peptidoglycan and the ability to perform photosynthesis. Explain how this microorganism should be classified in the five-kingdom classification system.
Solution: This microorganism should be classified in the Kingdom Monera. Monera includes bacteria, and the presence of peptidoglycan in the cell wall is a characteristic feature of bacteria. The ability to perform photosynthesis suggests that it belongs to a subgroup of bacteria known as Cyanobacteria or blue-green algae.

Section F. Short Answer Type

Q1: Explain the significance of the five-kingdom classification system in the field of biology.
Ans: The five-kingdom classification system provides a systematic and organized way to categorize and classify living organisms. It helps in:

• Understanding the diversity of life on Earth.
• Studying evolutionary relationships among organisms.
• Facilitating communication and study among scientists worldwide.
• Simplifying the naming and identification of organisms.
• Assisting in the conservation and management of biodiversity.

Q2: Differentiate between homologous and analogous organs with examples.
Ans: Homologous organs have a common evolutionary origin but may serve different functions, while analogous organs have different evolutionary origins but serve similar functions.

• Example of homologous organs: The forelimbs of vertebrates (human arm, bat wing, whale flipper) share a common ancestor and have similar bone structure despite different functions.
• Example of analogous organs: The wings of insects (e.g., butterfly) and birds (e.g., eagle) have different origins but both serve the function of flight.

Q3: Why are viruses not classified in any of the five kingdoms of the classification system?
Ans: Viruses are not classified in any of the five kingdoms because they do not possess the characteristics of living organisms. They lack cellular structure, metabolic processes, and the ability to reproduce independently. Viruses are considered as biological entities but fall outside the traditional classification system due to their unique properties.

Q4: What is phylogenetic classification, and how does it differ from the traditional five-kingdom classification?
Ans: Phylogenetic classification is a classification system based on evolutionary relationships among organisms. It differs from the traditional five-kingdom classification in that it takes into account genetic and evolutionary information, rather than solely relying on observable characteristics. Phylogenetic classification groups organisms into clades or groups based on shared ancestry, resulting in a more accurate representation of evolutionary history.

Q5: Explain the concept of binomial nomenclature with an example.
Ans: Binomial nomenclature is a naming system in which each species is given a two-part scientific name, consisting of the genus name (capitalized) and the species name (lowercase), both in italics or underlined.
Example: Homo sapiens

• Homo is the genus name.
• Sapiens is the species name.
• Together, they represent the scientific name for modern humans.

Q6: Who introduced the five kingdom classification of organisms?
Ans: R.H. Whittaker (1969)

Q7: To which kingdom the multicellular decomposers belong?
Ans: Kingdom fungus.

Q8: Expand PPLO.
Ans: Pleuro pneumonia like organisms.

Q9: Give one example of a fungus as a soure of antibiotics?
Ans: Penicillium is the genus which is the source of an antibiotic penicillin. Penicillium is known as green & blue moulds. Penicillium chryosogenum (P.notatum) is utilized for production of antibiotic penicillin.

Q10: How are viroids different from viruses?
Ans: VIRIODS

• Viriods are smaller than viruses & lack protein coat.
• Viruses are non- cellular (acellular) organisms having protein coat. ii) Genetic material is free RNA, which is infectious.

VIRUSES

• Viruses are non- cellular (acellular) organisms having protein coat.
• Genetic material is RNA or DNA.

Section G. Long Answer Type

• Eukaryotic, non-photosynthetic organisms.
• Cell walls made of chitin.
• Heterotrophic, obtaining nutrients through absorption.
• Reproduction by spores.
• Exhibit both unicellular (yeasts) and multicellular (mushrooms) forms.
• Play a vital role in decomposition and nutrient recycling.

Ecological Significance of Fungi:

• Decomposers: Fungi break down dead organic matter, recycling nutrients in ecosystems.
• Mycorrhizae: Fungi form symbiotic associations with plant roots, enhancing nutrient absorption.
• Pathogens: Some fungi cause diseases in plants, animals, and humans.
• Food Source: Edible fungi like mushrooms are consumed by humans.
• Biotechnology: Fungi are used in the production of antibiotics, enzymes, and food products.

Q2: Discuss the advantages and disadvantages of the three-domain system of classification as compared to the five-kingdom classification system.
Ans:
Three-Domain System:

• Advantages:
  • Reflects evolutionary relationships more accurately.
  • Recognizes the fundamental distinction between prokaryotes (Bacteria and Archaea) and eukaryotes (Eukarya).
  • Allows for the inclusion of Archaea as a separate domain.
• Disadvantages:
  • May be complex for introductory biology.
  • Doesn't provide as simple a framework as the five-kingdom system for educational purposes.

Five-Kingdom Classification:

• Advantages:
  • Simpler and easier to understand for beginners.
  • Well-established and widely used.
  • Provides a broad overview of biological diversity.
• Disadvantages:
  • Doesn't reflect evolutionary relationships accurately.
  • Doesn't differentiate between prokaryotes effectively.

Q3: Discuss the salient features of viruses with the help of diagram?
Ans: Features of viruses:

• They are smaller then bacteria.
• They can be filtered and crystallized.
• They are able to reproduce in host cell by using enzymes & metabolic machinery of host cell
• DNA/RNA is their genetic material
• These are obligate parasites, self replicating & non - cellular organisms.
• They have protein coat called capsid (unit is capsomere) that protects nucleic acid.
• They cause disease in plants like mosaic, leaf curling, leaf role, vein clearing etc.

Q4: Write the distinct characters of fungi & explain using a diagram.
Ans:

• Cell type - eukaryotic.
• Cell wall - present but made up of chitin.
• Chloroplast - absent.
• Mitochondria - present
  
• Nuclear envelope - present
• Tissues - present but limited, only yeast is a unicellular fungi, hyphae mycelium coenocytic, septate
• Motility - Cilia, flagella in some treat absent in most forms.
• Nutrition - Heterotrophic, saprophytes, parasites, absorb food or as symbionts in lichens
• Reproduction - fertilization or meiosis in sexual reproduction & fission, budding fragmentation, conidia formation etc in asexual reproduction.
• Nervous system - absent
• Occurrence - air, water, soil, animals or plants
• Examples - yeast, Penicillium, Agaricus, Rhizopus, phytophthora, Asperigillus claviceps.