All questions of Biodiversity for Grade 9 Exam

Deforestation is the process of cutting down trees and clearing forests or woodlands, typically to make way for agricultural or urban development. This process has a significant impact on the environment and can result in the extinction of many species. The following are the reasons why deforestation is the main reason for species extinction:

1. Loss of habitat: Deforestation leads to the destruction of natural habitats of many species. Trees provide homes for animals, birds, and insects. When these habitats are destroyed, the animals are forced to migrate, which can lead to the extinction of the species.

2. Fragmentation of ecosystems: Deforestation fragments ecosystems, creating isolated pockets of habitat that are too small to sustain a viable population of many species. As a result, many species become extinct due to the lack of genetic diversity and the inability to find mates.

3. Climate change: Trees absorb carbon dioxide from the atmosphere and release oxygen. The destruction of forests leads to an increase in carbon dioxide levels, which contributes to climate change. Climate change can cause the extinction of many species that cannot adapt to the changing environment.

4. Hunting and poaching: Deforestation also leads to an increase in hunting and poaching activities, as many species are displaced from their natural habitats. This further increases the risk of extinction for many species.

In conclusion, deforestation is the main reason for species extinction as it leads to the loss of habitat, fragmentation of ecosystems, climate change, and an increase in hunting and poaching activities. It is, therefore, essential to implement measures to protect forests and prevent their destruction to conserve biodiversity and prevent the extinction of many species.

Presently, 12% all the birds species, 23% all mammals species, 31% all gymnosperms species and 32% all amphibian species in world face the threat of extinctions.

Rauwolfia vomitoria is the source of active chemical drug reserpine, which is prescribed in hypertension and act as tranquilliser. 

Red Data Book is a state document established for documenting rare and endangered species of animals, plants and fungi, as well as some local subspecies (such as the Ladoga seal) that exist within the territory of the Russian Federation and its continental shelf and marine economic zone. The book has been adopted by Russia and all CIS states to enact a common agreement on rare and endangered species protection.

Red data books are produced by IUCN, which stands for the International Union for Conservation of Nature. These books are a type of conservation tool used to identify and assess the conservation status of various species around the world.

The IUCN Red List of Threatened Species is the most well-known red data book produced by the organization. This list provides a comprehensive overview of the conservation status of tens of thousands of species, including mammals, birds, reptiles, fish, and plants.

The main purpose of red data books is to provide information on species that are at risk of extinction or are already extinct. This information can be used to inform conservation efforts, such as habitat preservation, captive breeding programs, and wildlife reintroduction programs.

Red data books typically include information on the following:

- The scientific name of the species
- The common name of the species
- The population size of the species
- The geographic range of the species
- The habitat of the species
- The reasons why the species is at risk of extinction
- The conservation measures that are being taken to protect the species

In addition to the IUCN Red List, other organizations also produce red data books that focus on specific regions or groups of species. For example, the European Red List is produced by the European Commission and includes information on the conservation status of European species.

Overall, red data books are an important conservation tool that helps to raise awareness about the plight of endangered species and inform conservation efforts around the world.

Understanding Paul Ehrlich's Analogy
Paul Ehrlich's analogy highlights the importance of species in ecosystems and their functionalities. Let's break down the provided options and clarify why option 'D' is considered incorrect.
Key Species vs. Less Important Species
- Option (a) states that the loss of key species, which drive major ecosystem functions, poses a greater threat to ecosystem stability than the loss of less important species. This is accurate; key species often play critical roles (e.g., pollinators, top predators) that maintain ecological balance.
Initial Ecosystem Resilience
- Option (b) suggests that the proper functioning of an ecosystem may initially remain unaffected by species loss. This is also valid; ecosystems can often absorb some level of species loss without immediate impact, showcasing resilience.
Long-Term Effects of Continuous Species Loss
- Option (c) emphasizes that continuous species loss will eventually impact ecosystem health over time. This is correct, as prolonged loss can disrupt food webs and ecological processes.
Misconception of Insignificant Species
- Option (d) claims that even the loss of not very significant species can lead to critical damage to ecosystems. This statement is misleading. While all species contribute to ecosystem dynamics, not all species have equal impact. Some species may be redundant and their loss may not result in immediate critical damage.
Conclusion
In conclusion, option 'D' is considered incorrect because it overemphasizes the significance of lesser species in causing critical damage to ecosystems. The reality is that while biodiversity is crucial, not all species hold equal weight in maintaining ecosystem stability.

Understanding Biodiversity and the Correct Statements
The question presents three statements regarding biodiversity, and the correct answer is option 'A', which states that both statements b and c are correct. Let's explore each statement:
Statement A: Biodiversity and Latitude
- Biodiversity generally decreases as one moves from the equator towards the poles.
- Tropical regions at low latitudes are rich in species diversity, while higher latitudes tend to have fewer species.
- Therefore, statement A is incorrect.
Statement B: Rivet Popper Hypothesis
- The rivet popper hypothesis, proposed by Paul Ehrlich, uses the metaphor of rivets on an airplane wing to illustrate the importance of biodiversity.
- In this analogy, each rivet represents a species; losing species (or rivets) can lead to the failure of the ecosystem (or airplane).
- The key species in this analogy are not referred to as "rivets on the wings," making statement B incorrect.
Statement C: Species Diversity in India
- India is recognized as a biodiversity hotspot, containing approximately 8.1% of the world's species diversity.
- This statistic reflects the rich variety of flora and fauna in the country, making statement C correct.
Conclusion
- Therefore, the correct answer should highlight that statement C is correct, while statement A and B are incorrect.
- As per the question's assertion, the answer should be 'd' (a and c only) if it were accurate, but given the context, it's clear that the understanding of the statements needs clarification.
In summary, while the correct answer provided is option 'A', it should be noted that the statements regarding biodiversity and the rivet popper hypothesis need to be carefully evaluated for accuracy.