Class 9th
Biology
Chapter 03
Biodiversity
Exercise Solution
Encircle the best suitable answers.
1. Which character of viruses makes their resemblance with living organisms?
a. They can be crystallized
b. They cannot live outside host body
c. They contain DNA or RNA
d. All of the above
Answer = c) They contain DNA or RNA
2. Euglena belongs to the kingdom Protista because:
a. It is Unicellular
b. It is Eukaryotic
c. It has both plant and animal like characters
d. It lives in water
Answer = c) it has both plant and animal like characters
3. The correct sequence of hierarchy from small to large units is:
a. Genus→Family→Order→Class
b. Family → class→order→genus
c. Genus→family →class→Order
d. Species-family → genus→Class
Answer = a Genus→Family→Order→Class
4. The kingdom which contains eukaryotic, autotrophic organisms is:
a. Protista
b. Monera
c. Fungi
d. None of them
Answer = a) protista
5. The Five kingdom system of classification was modified by:
a. Robert Whittakar
b. Margulis and Schwartz
c. Carolus Linneaus
d. Aristotle
Answer = b) Margulis and Schwartz
6. Aristotle classified organisms on the basis of:
a. Habitats
b. Morphology
c. Cell structure
d. Anatomy
Answer= a) Habitat
7. Which of the following kingdoms possesses the simplest organism?
a. Fungi
b. Monera
c. Protista
d. Plantae
Answer = b) Monera
8. What is binomial nomenclature?
a. Classifying organisms on seven levels
b. Naming system developed by Aristotle
c. Grouping animals based on their habitat
d. Naming system in which each organism is given a two-part name
Answer = d (Naming system in which each organism is given a two-part name)
9. Which one is the correct way of writing scientific name of an organism?
a. Canis lupus
b. Saccharum
c. Giant’s gazelle
d. Escherichia coli
Answer = d) Escherichia coli
10. Which kingdom includes organisms with cell wall but without chlorophyll?
a. Protista
b. Fungi
c. Plantae
d. Animalia
Answer = b). Fungi
11. Which one is the basic unit of classification?
a. Genus
b. Species
c. Family
d. Order
Answer = b) Species
12. Maximum biodiversity is found in:
a. Forests
b. Grasslands
c. Deserts
d. Mountains
Answer = a) Forests
Write short answer to the following questions
1. How does deforestation leads to desertification?
- Deforestation is the removal of trees in unwise manner.
- Due to deforestation natural habitats of plants and animals are destroyed.
- Plants and trees hold the soil in place.
- Their roots bind the soil particles and stop soil erosion.
- If there are no trees, the floods and heavy rains wash the soil and its nutrients into the rivers causing deserts in that area.
- So deforestation leads to desertification.
2. Why is it important for a biologist to understand biological classification?
- Biological classification is important for biologists
Reason
- It organizes the diversity of life, facilitates communication, reveals evolutionary relationships, aids in predicting characteristics, supports biodiversity conservation, enhances ecological research, and informs medical and agricultural practices.
3. What is the status of viruses in classification?
- Viruses do not fit into any kingdom of classification.
- They are excluded from five kingdom system because:
- They are neither plants nor animals.
- They show both the characters of living and non living organisms.
4. How you can differentiate between kingdom Monera and Protista?
| Living Characters | Non living Characters |
| It can reproduce | Virus are not made of cell |
| It has DNA | Don’t have metabolic process |
| It can evolve over time | Outside host it is inert(non reactive) |
| Monera | Protista |
| They are prokaryotes | They are eukaryotes |
| Cell wall made of murine | Algae have cell wall while other not |
| They reproduces asexually | They reproduces asexually and sexually |
| Example (Bacteria, Cyanobacteria) | Example (Algae, Amoeba) |
5. List down the endangered species of Pakistan and what are the reasons behind their population decrease.
Endangered Animals:
- Markhor
- Blind dolphin
- Marcopolo sheep
- Tilor
Endangered Plants
- Chilghoza
- Sanobar
Causes of extinction:
- Distraction of natural habitat
- Over hunting
- Deforestation
- Water logging and salinity
- Industrialization
Give detailed answers to the following questions
Q 1. Differentiate between two kingdom system and five kingdom system along their advantages and disadvantages.
Two Kingdom system:
- It was proposed by Carolus Linnaeus in 1751.
- Organisms are classified into 2 kingdoms
- It is based on nutrition and motility
- The placement of organisms like Euglena, bacteria, fungi in plantae is questionable due to certain reasons
Five Kingdom system:
- It was proposed by Robert Whittakar in 1969.
- Organisms are classified into 5 kingdoms
- It is based on the cell structure, complexity of body, mode of nutrition and evolution
- Organisms are better placed on the basis of body, cell structure and evolution
Advantages of the Two-Kingdom System:
1. Simplicity :
- Provides a straightforward and easy-to-understand framework by dividing life into two broad categories: Animalia (animals) and Plantae (plants).
2. Historical Significance:
- As one of the earliest classification systems, it laid the foundation for the development of modern taxonomy and biological classification.
3. Educational Tool:
- Useful in early biological studies for introducing the concept of classification without overwhelming complexity.
Disadvantages of the Two-Kingdom System
1. Over-Simplification:
- Does not accurately represent the diversity of life, as many organisms do not fit neatly into either kingdom.
ii . Exclusion of Microorganisms:
- Fails to accommodate microorganisms like bacteria and fungi, which have distinct characteristics that do not align with plants or animals.
3. Inaccurate Groupings:
- Struggles to classify organisms with characteristics of both plants and animals, such as Euglena.
Advantages of the Five-Kingdom System
1. Greater Diversity Recognition
- Recognizes and categorizes a wider variety of life forms, dividing organisms into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia
2. Inclusion of Microorganisms
- Accounts for microorganisms by including kingdoms like Monera (bacteria) and Protista, providing a place for organisms that don’t fit into the traditional plant or animal categories
3. More Accurate Classification:
- Better reflects the complexity of life by distinguishing between different types of organisms based on cell structure, mode of nutrition, and other fundamental differences.
Disadvantages of the Five-Kingdom System
1. Complexity:
- More complex than the two-kingdom system, which can be challenging for beginners to grasp and teach.
2. Overlaps and Ambiguities:
- Some organisms, particularly those in the Protista kingdom, are diverse and not easily categorized, leading to ambiguities and overlaps.
3. Outdated with New Discoveries:
- The advent of molecular phylogenetics and the discovery of archaea as distinct from bacteria have made the five-kingdom system somewhat outdated, leading to the development of the three-domain system.
Q 2. Take one organisms and assign it to different ranks according to hierarchy of taxonomy.
Taxonomic Hierarchy for the Domestic Cat
- Domain: Eukarya
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Carnivora
- Family: Felidae
- Genus: Felis
- Species: Felis catus
Q 2. How human activities affect the biodiversity of an area?
- Human activities significantly impact the biodiversity of an area in numerous ways.
1. Habitat Destruction
a) Deforestation:
- Clearing forests for agriculture, logging, and urban development reduces habitats for many species
b) Urbanization:
- Expanding cities and infrastructure replace natural habitats with buildings and roads.
c) Agriculture:
- Converting wild areas into farmland often involves the removal of native vegetation and can lead to habitat fragmentation.
2. Pollution
a) Air Pollution:
- Emissions from industries and vehicles can lead to acid rain, which harms plants and aquatic ecosystems
b) Water Pollution:
- Contaminants from agricultural runoff, industrial waste, and sewage can degrade water quality, affecting aquatic life
c) Soil Pollution:
- Pesticides, herbicides, and heavy metals can contaminate soil, impacting plants and organisms that live there.
3. Climate Change
a) Global Warming:
- Rising temperatures affect species’ survival, migration patterns, and breeding seasons
b) Extreme Weather Events:
- Increased frequency of storms, droughts, and floods disrupt ecosystems and can lead to loss of species
c) Sea Level Rise:
- Melting polar ice caps and thermal expansion of water threaten coastal habitats and marine life.
Q 4. Explain Binomial Nomenclature. What are its advantages?
“Bi” means ”two” “nomen” means “name” “clature” means “system”
- Two naming system of organisms is called binomial nomenclature.
- This system was developed by Carl Linnaeus in the 18th century and is the foundation of modern taxonomy.
- The two parts of the binomial name are:
Genus Name:
- The first part of the name, which is always capitalized and italicized (or underlined if handwritten).
- It indicates the genus to which the species belongs.
Species Name:
- The second part of the name, which is lowercase and also italicized (or underlined if handwritten).
- It differentiates the species within the genus.
For example, in the name Homo sapiens:
- Homo Is the genus.
- sapiens is the species .
Advantages of Binomial Nomenclature:
1. Universal Standardization:
- Binomial nomenclature provides a universal and standardized system for naming species, which is recognized and used by scientists worldwide.
- This avoids confusion that can arise from common names that vary by region and language.
2. Clarity and Precision:
- Each species has a unique name, reducing ambiguity.
- This precise identification is crucial for scientific communication, research, and conservation efforts.
3. Reflects Relationships:
- The system reflects the hierarchical classification and evolutionary relationships among species.
- The genus name groups related species together, indicating a shared ancestry.
Q 5. What are the reasons for the extinction of biodiversity worldwide and What measures are required to conserve the biodiversity of Pakistan?
Reasons for the Extinction of Biodiversity:
A) Worldwide Habitat Destruction:
i. Deforestation:
Clearing forests for agriculture, urbanization, and logging.
ii. Urban Expansion:
Development of cities and infrastructure encroaching on natural habitats.
iii. Agricultural Conversion:
Transforming natural landscapes into farmland, often leading to monocultures.
B) Pollution:
i. Air Pollution:
Emissions leading to acid rain, which harms ecosystems.
ii. Water Pollution:
Contaminants from industrial waste, agricultural runoff, and sewage harming aquatic life.
iii. Soil Pollution:
Chemicals and heavy metals affecting soil quality and organisms.
C) Climate Change:
i. Global Warming:
Altering habitats and affecting species’ survival, migration, and reproduction.
ii. Extreme Weather:
Increased frequency of storms, droughts, and floods disrupting ecosystems.
iii. Sea Level Rise:
Threatening coastal habitats and marine species.
D) Overexploitation:
i. Hunting and Poaching:
Unsustainable hunting for food, sport, or trade.
ii. Overfishing:
Depleting fish stocks and damaging marine ecosystems.
iii. Logging and Mining:
Excessive extraction of resources leading to habitat degradation.
D) Invasive Species:
i. Introduction of Non-Native Species:
Competing with, preying on, or bringing diseases to native species.
ii. Ecosystem Imbalance:
Disruption of local ecosystems leading to native species decline.
Q 6. Measures to Conserve the Biodiversity of Pakistan:
A) Protected Areas:
i. Establish and Expand:
Increase the number and size of national parks, wildlife reserves, and marine protected areas
ii. Effective Management:
Implement strong management plans for existing protected areas to ensure they are effectively conserving biodiversity.
B) Habitat Restoration:
i. Reforestation and Afforestation:
Plant native trees and restore degraded forests.
ii. Wetland Restoration:
Revive and protect wetlands that are crucial for many species.
C) Sustainable Practices:
i. Sustainable Agriculture:
Promote agroforestry, organic farming, and other sustainable agricultural practices.
ii. Sustainable Fishing:
Implement regulations to prevent overfishing and protect marine ecosystems.
D) Pollution Control:
i. Reduce Industrial Emissions:
Enforce regulations to reduce air, water, and soil pollution from industries.
ii. Waste Management:
Improve waste collection and recycling programs to reduce pollution.
E) Climate Change Mitigation:
i. Reduce Carbon Emissions:
Promote renewable energy sources and energy efficiency.
ii. Adaptation Strategies:
Develop strategies to help ecosystems and communities adapt to changing climate conditions.
Class 9th Biology Chapter 02 Exercise Solution
