Q#1 Define the term Biodiversity. Explain your answer
Definition of Biodiversity
A wide range variety of living organisms on earth is called biodiversity.
Explanation
Biodiversity includes a wide range of living organisms such as microorganisms, plants, animals, insects, mollusks, etc. These organisms show some common similarities but also have differences in size, shape, colors, morphology (Structure), behavior, and reproduction. These differences between living organisms are commonly called biodiversity.
Biodiversity is not distributed uniformly on the earth. The biodiversity of an area depends on climate, altitude, the composition of the soil, etc.
Number of types of organisms
There are about two million different types of organisms on the earth. In Pakistan, there are 23,000 types of animals.
Q#2: State the importance of biodiversity briefly.
Importance of biodiversity
1. Provides knowledge of other life forms
Biodiversity provides knowledge about different kinds of living organisms from microscopic to complex, which we know only due to biodiversity.
2. Food for human beings
Biodiversity provides a high variety of food for humans such as crops, livestock, forestry, and fish.
3. Production of drugs
Biodiversity helps in the production of different drugs such as streptomycin, neomycin, and erythromycin are derived from fungi and caffeine, morphine, quinine, etc. from different plants.
4. Industrial benefits
Biodiversity plays an essential role in the production of industrial materials such as building materials, fibers, dyes, resins, gums, adhesive, rubber, and oil derived from plants.
5. Relation with ecosystem
Biodiversity is an essential component of an ecosystem. Each specie has a specific role in the ecosystem. The loss of species makes the ecosystem less productive.
Q#3: What is classification also write the basis of classification.
Classification
The arrangement of organisms into groups and sub-groups on the basis of similarities and differences is called classification.
There are about 2 million kinds of organisms (0.5 million types of plants and 1.5 million of animals), so its classification is essential.
Basis of classification
Previously organisms were classified on the basis of habitat and physical characteristics. Habitats include air, water, and land while some characteristics were prokaryotic and eukaryotic, photosynthetic, or heterotrophic. Now the modern classification is not based on habitat and physical characteristics but also on genetics, anatomy, physiology, and evolutionary history.
Q#4: Write down the aims and principles of classification.
Aims of classification
The main aims of classification are
- To determine the similarities and differences among organisms, so they can be studied easily.
- To provide an idea about the sequence of evolution of organisms from simple to complex.
- To express relationships based on common features.
- To name and place the organisms in the proper taxonomical group.
Principles of classification
The
main principles of classification are
- Organisms are classified on the basis of clear similarities among them.
- Organisms are classified in one group or in closer groups if they have some homologous (similar) structures.
- The anatomical features and evolutionary history is also considered during classification.
Q#5: What is a hierarchy of taxonomy?
Taxonomy
The branch of biology that deals with the study of naming and classification of organisms is called taxonomy.
Hierarchy of taxonomy
The taxonomical category from species to the kingdom is called the hierarchy of taxonomy.
Carolus
Linnaeus
proposed a system of different ranks or levels for the classification of an
organism. Such ranks or levels are called taxa (singular taxon).
The main taxa of classification are
1. Species
A group of organisms that can interbreed naturally and produce fertile offspring is called species.
It is the basic and smallest unit of classification. The members of a specie have the same number of chromosomes e.g. all humans have 46 chromosomes and belong to the same species called sapiens.
2. Genus
A group of species that are similar in some characters forms the next level of classification called a genus.
For example, cats, lions, and tigers have the same genus called ‘Felis’ but are different species.
3. Family
Closely related genera are grouped into a family.
4. Order
Closely related families are grouped into order.
5. Class
Closely related orders are grouped into a class.
6. Phylum
Closely related classes are grouped into a phylum.
7. Kingdom
Closely related phyla are grouped into a kingdom.
The kingdom is the largest unit of classification. These taxa also have sub-categories except genus e.g. species and sub-species, order, and sub-order.
Q#6: Explain Binomial Nomenclature. What are its advantages/ importance?
Binomial nomenclature (Bi=two, Nomial=naming, nomenclature=system)
The two words naming system is called binomial nomenclature.
Binomial nomenclature was developed by Swedish scientist
Carolus Linnaeus in 1753.
Rules of binomial nomenclature
- According to this system, each organism has a specific biological name which consists of two words.
- The first word of the name is the genus name, which begins with a capital letter.
- The second word of the name is the specie name, which begins with a small letter.
- Both words are written in italics or underlined.
Importance of binomial nomenclature
- According to this system, every organism has a specific biological name by which it is known all over the world.
- As no two organisms have the same name, so it avoids the confusion in the names which is present in local names.
- Biological names are definite and precise.
- Being generally in Latin, the biological names are accepted all over the world.
- This shows the relationship to other genera of the group.
Q#7: What is conservation of biodiversity? Also, discuss the impacts of humans on biodiversity.
Conservation of biodiversity
The management, protection, and preservation of natural resources is called conservation.
Conservation of biodiversity means using natural resources such as plant life, animal life, marine life, and aquatic life in a judicious.
Impact of humans on biodiversity
- Overpopulation results in the destruction of biodiversity.
- Building new infrastructures and housing destroy valuable habitats.
- Deforestation is directly linked with soil erosion and desertification.
- Many plant and animal species have become endangered by human intervention.
- Due to degradation of natural habitats and illegal hunting 31 species of mammals, 20 species of birds, 5 species of reptiles, and many plant species are listed as endangered in the country.
- Overgrazing of green land has extensively decreased the productivity areas.
- Many medicinal plant species have been destroyed due to human interference.
Q#8: What are endangered species? Write endangered species of Pakistan.
Endangered species in Pakistan
The plants and animals which are so reduced in their population number as to be on the verge of extinction are called endangered species.
Examples:
In Pakistan, plants like Taxus baccata (yew), pinus gerandiana (chilghoza), juniperus marcopoda (sanobar), Ruff lisia, and grass ferm have become endangered. In animals Houbara bustard (talor), Giant pandas, carpra falconeri (Markhor), Marcopole sheep, Musk deer etc. are endangered species.
Q#9: Define extinct, endangered, and threatened species.
Extinct species
A specie that no longer lives anywhere on the earth is called extinct specie.
Endangered species
The species which are so reduced and are near to extinction are called endangered species.
Threatened species
The species which are to become endangered in the near future are called threatened species.
Q#10: Write the effects of human activities on biodiversity.
1. Habitat loss and deforestation
All species have specific food and habitat needs. Habitat loss means the destruction of natural habitat of species. In order to cope with the demands of food, people are clearing forests and developing agricultural land and residential colonies. The forest area in Pakistan in only 2.5%. According to a report of WWF, since 1947 more than 151,500 acres of forest land have been converted to non-forest land.
2. Over-hunting
It is also a cause of loss of biodiversity. In Pakistan, various lizards, snakes, crocodiles and larger mammals are hunted for various purposes.
3. Introduction or Removal of species
When a new specie is introduced in an ecosystem, it may prove harmful. For example, Eucalyptus trees were imported in Pakistan from Australia. These tree consume more water and thus disturbed the level of underground water. Similarly, when a specie is removed from an ecosystem, it also affects other species. For example, starfish eats mussels which are harmful to many other species.
Q#11: What is deforestation? What are its causes and effects?
Deforestation
The unwise and unplanned destruction or removal of trees is known as deforestation.
Importance of forests
- Forests are natural factories for producing Oxygen.
- They provide green cover to the earth.
- They provide a living place for wildlife.
- Forests provide timber, fuel, and recreation to man.
- They prevent soil erosion, floods, and the formation of deserts.
Causes of deforestation
- Trees are removed to build roads and houses for a growing population.
- Forests are removed to bring more land for cultivation.
- Trees are cut to get timber and fuel wood.
- Trees are also removed to develop pasture for grazing.
- The timber mafia cut the trees for easy cash.
Effects of deforestation
- Deforestation leads to soil erosion.
- It causes the destruction of habitats for wildlife.
- It results in the extinction of many species.
- Deforestation results in flooding.
- It leads to climatic changes i.e. low rainfall and global warming etc.
- Cutting down of forests decrease recreation sources.
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