Biodiversity Lecture 5

Questions and Answers

What is the primary factor that species richness tends to decline with?

Geographic location (correct)

Soil diversity

Proximity to water sources

Altitude

Which statement correctly describes keystone species?

Elimination can greatly affect the structure of the ecosystem. (correct)

Their introduction always leads to an increase in biodiversity.

They have no significant impact on their ecosystem.

They are the most abundant species in any ecosystem.

What percentage of all amphibian species are facing extinction?

33% (correct)

50%

10%

25%

Which of the following is NOT a factor in the decline of amphibian populations?

Adaptive coloration changes Signup and view all the answers

What constitutes a biome?

A collection of different ecosystems with similar features Signup and view all the answers

Which range of average annual precipitation defines an ecosystem with high species diversity?

Above 125 cm Signup and view all the answers

What effect does high species richness have on ecosystem sustainability?

Improves sustainability and productivity Signup and view all the answers

Which of the following is a significant factor causing amphibian declines?

Overhunting Signup and view all the answers

What does biodiversity refer to?

The variety of life at all levels of biological organization Signup and view all the answers

What is species richness?

The number of species in a given area Signup and view all the answers

Which factor does NOT directly affect biodiversity?

Meteorological patterns Signup and view all the answers

What is speciation?

The process where one species splits into two or more species Signup and view all the answers

Which of the following represents intra-specific genetic diversity?

Genetic variations within a population of the same species Signup and view all the answers

Which of the following groups is likely to contain poorly known species?

Viruses, fungi, and protists Signup and view all the answers

Which level of biodiversity describes a set of individuals that can mate and produce fertile offspring?

Species diversity Signup and view all the answers

What happens to genetic diversity within populations over time?

It can change depending on evolutionary rates Signup and view all the answers

What adaptation do Arctic Foxes have that aids in camouflage?

Heavier fur Signup and view all the answers

Which physical trait helps the Gray Fox adapt to hot environments?

Long ears Signup and view all the answers

What type of forest is associated with the Sierra Nevada region?

Coniferous forest Signup and view all the answers

Which biodiversity type refers to the number and abundance of species?

Species Diversity Signup and view all the answers

What environmental factor has a significant influence on the adaptations of the Arctic and Gray Foxes?

Climatic conditions Signup and view all the answers

What type of ecosystem diversity refers to the variety of ecosystems in a geographical area?

Ecological Diversity Signup and view all the answers

In what way does the Northern population of the Early fox differ from the Southern population?

Adaptations to cold Signup and view all the answers

Which of the following is NOT a type of forest described in the content?

Desert forest Signup and view all the answers

What is necessary for adaptive traits to spread rapidly in a population?

High reproductive capacity Signup and view all the answers

Which of the following statements accurately reflects a myth about evolution through natural selection?

Genetic perfection is a trend in evolution. Signup and view all the answers

How do geological processes impact species development?

They can wipe out species and create new habitats. Signup and view all the answers

What effect do long-term climate changes have on species?

They lead to the evolution of new species and extinction of many. Signup and view all the answers

How do current human activities affect biodiversity?

They cause premature extinction and habitat degradation. Signup and view all the answers

What is meant by the term 'ecological niche'?

The role and position a species has in its environment, including resources it needs Signup and view all the answers

Which of the following describes generalist species?

Species that can thrive in a wide variety of environments Signup and view all the answers

How do populations evolve over time?

As a result of mutations that alter genetic information Signup and view all the answers

What role does natural selection play in evolution?

It allows organisms with helpful traits to reproduce more successfully Signup and view all the answers

What limits adaptation through natural selection?

The existing traits already present in the gene pool Signup and view all the answers

What is a characteristic of nonnative species?

They compete with native species for resources Signup and view all the answers

Which of the following best describes genetic variability?

It arises from random mutations and can lead to heritable traits Signup and view all the answers

What evidence do fossils provide in studying biodiversity?

They document the historical life forms that existed, despite being incomplete Signup and view all the answers

Study Notes

Concept of Biodiversity

Biodiversity encompasses genetic diversity, species diversity, and ecosystem diversity.
Considered essential for sustaining life on Earth and maintaining ecological balance.

Distribution of Biodiversity

Estimated between 8-100 million species exist globally, with 10-14 million likely identifiable.
Approximately 2 million species have been formally described; a large number remain undocumented, especially in tropical rainforests.

Biodiversity Levels

Genetic Diversity: Refers to the variety of genes within species, crucial for adaptability and evolution. Genetic variation dictates evolutionary rates.
Species Diversity: Consists of species richness (number of species) and evenness (distribution of species). Species diversity typically declines towards poles.
Ecosystem Diversity: Represents various ecosystems within a biome; influences the balance of ecological functions.

Speciation

Occurs when a species divides into two or more distinct species unable to interbreed.
Can result from geographic or reproductive isolation, significantly affecting biodiversity.

Importance of Keystone Species

Keystone species have a large impact on their ecosystems—a change in their population can affect community structure.
Examples include pollinators and top predators; their elimination can lead to significant ecological shifts.

Threats to Biodiversity

Habitat loss, pollution, climate change, overhunting, and introduction of nonnative species are primary threats to biodiversity.
Amphibians are particularly affected, with one-third facing extinction.

Functional and Ecological Diversity

Functional Diversity: Refers to the variety of processes such as energy flow and nutrient cycling within ecosystems.
Ecological Niche: Every species occupies a specific niche, fulfilling certain roles related to habitat, food, and environmental needs.

Evolution and Natural Selection

Natural selection drives evolution; populations evolve when advantageous traits provide a survival advantage.
External factors like climate changes and geological processes can influence speciation and biodiversity.

Human Impact on Biodiversity

Human activities contribute to biodiversity loss through habitat destruction and species extinction.
The interplay between human-driven changes and natural processes complicates the future of biodiversity.

Future of Biodiversity Studies

Ongoing research focuses on understanding biodiversity’s role in ecosystem health and resilience.
Conservation efforts aim to mitigate threats and promote the sustainable use of biological resources.

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Description

Explore the key concepts of biodiversity in this Lecture 5 by Dr. Hadil Alahdal. The quiz covers the distribution of biodiversity, its significance in maintaining ecological balance, and the various threats it faces. Additionally, gain insights into the future of biodiversity studies.