Biodiversity

Question 1

What does biodiversity refer to?

Answer 1

The variety of living organisms in an area.

Can be considered at different levels:

Habitat biodiversity – number of different habitats in an area.

Species biodiversity – species richness and evenness.

Genetic biodiversity – genetic variation within a species.

Question 2

Why is biodiversity important?

Answer 2

Ecosystem stability – diverse ecosystems are more resilient.

Economic value – resources for medicine, agriculture, and tourism.

Ecological balance – interdependent species support ecosystems.

Aesthetic and cultural value – natural beauty and well-being.

Question 3

What is the difference between species richness and species evenness?

Answer 3

Species richness: The number of different species in an area.

Species evenness: The relative abundance of each species.

Both are used to calculate biodiversity in an ecosystem.

Question 4

What is genetic biodiversity, and why is it important?

Answer 4

The variety of alleles within a species.

High genetic biodiversity allows species to adapt to environmental changes and resist diseases.

Question 5

What are the two main types of sampling?

Answer 5

Random sampling – Every individual has an equal chance of selection (e.g., using random coordinates).

Non-random sampling – Individuals are selected based on certain criteria:

Systematic sampling – Samples taken at fixed intervals (e.g., along a transect).

Opportunistic sampling – Chosen based on availability (less representative).

Stratified sampling – Dividing a population into groups and sampling proportionally.

Question 6

What are methods for sampling animals?

Answer 6

Sweep nets – Catch flying insects in vegetation.

Pitfall traps – Catch ground-dwelling insects.

Tullgren funnel – Extracts invertebrates from leaf litter.

Kick sampling – Collects aquatic organisms from rivers.

Question 7

What are methods for sampling plants?

Answer 7

Quadrats – Measure percentage cover or species frequency.

Point frame – Records species touching the frame.

Transects – Line or belt transects assess change across an area.

Question 8

How can sampling be made more reliable?

Answer 8

Increase sample size.

Use random sampling to reduce bias.

Repeat measurements and take an average.

Question 9

What is Simpson’s Index of Diversity?

Answer 9

1 - (Σ n(n-1) / N(N-1))
where ‘n’ is the number of individuals of a particular species, and ‘N’ is the total number of individuals in the sample
Higher values indicate greater biodiversity.

Question 10

How does the Mark-Release-Recapture method estimate population size?

Answer 10

Capture and mark individuals.

Release them back into the habitat.

Recapture a sample and count marked individuals.

Use the formula:

Populationsize = numberinfirstsample ×
numberinsecondsample/
numberofmarkedrecaptures

Question 11

What is biodiversity and what are the levels it can be measure on, and how is it linked to ecosystem stability?

Answer 11

Biodiversity refers to the variety of species in an area.

There are three main types of biodiversity: species diversity, ecosystem diversity, and genetic diversity. Species diversity refers to the variety of species within an ecosystem, ecosystem diversity refers to the variety of ecosystems, and genetic diversity refers to the variety of genetic material within species.

Greater biodiversity usually means a more stable and resilient ecosystem.

Question 12

Why isn’t species richness alone a good measure of biodiversity?

Answer 12

It doesn’t account for how evenly individuals are distributed among species — species evenness also matters.

Question 13

What is Simpson’s Index of Diversity and how is it calculated?

Answer 13

It’s a measure of biodiversity that considers both species richness and evenness.
Formula: D = 1 − Σ(n/N)²
n = number of individuals of one species
N = total number of individuals of all species
Σ = sum of (n/N)² for all species

Question 14

How do low and high biodiversity habitats differ?

Answer 14

Low biodiversity: Few species, harsh conditions, specialised adaptations, simple food webs, major impact from change

High biodiversity: Many species, stable environment, generalist adaptations, complex food webs, small impact from change

Question 15

How does environmental stress affect biodiversity?

Answer 15

High environmental stress reduces biodiversity because fewer species are adapted to survive in extreme or limited conditions.

Question 16

Why is it important to conserve both high and low biodiversity habitats?

Answer 16

High biodiversity supports ecosystem stability; low biodiversity may contain rare, highly specialised species not found elsewhere.

Question 17

Why is maintaining genetic biodiversity important for a species?

Answer 17

It ensures long-term survival by enabling individuals to withstand diseases and reducing problems from in-breeding. It allows species to adapt to environmental changes, making them less likely to become extinct.

Question 18

What is genetic biodiversity and how is it created?

Answer 18

It’s the variation in alleles within a species. It is created by:
- Mutation (new alleles).
- Interbreeding between populations (allele transfer).

Question 19

What factors can reduce genetic biodiversity?
A:

Answer 19

• Selective breeding.
• Captive breeding programmes.
• Rare breeds.
• Artificial cloning (asexual reproduction).
• Natural selection.
• Genetic bottlenecks.
• The founder effect.
• Genetic drift.

Question 20

How do selective breeding and captive breeding affect genetic biodiversity?

Answer 20

Selective breeding reduces gene pool by breeding only individuals with desired characteristics. Captive breeding involves a small number of breeding individuals, limiting diversity.

Question 21

What is a genetic bottleneck and the founder effect?

Answer 21

Genetic bottleneck: When few individuals survive an event, reducing genetic diversity.

Founder effect: When a small group starts a new population, leading to low biodiversity.

Question 22

What is genetic drift and how does it impact genetic biodiversity?

Answer 22

Genetic drift is a random change in allele frequency, more significant in small populations, reducing genetic biodiversity.

Question 23

What are polymorphic gene loci and how are they measured?

Answer 23

A gene locus (plural: loci) is the fixed position of a gene on a chromosome. A polymorphic gene locus is a gene locus with more than one allele present in the population. The proportion of polymorphic gene loci is a way to measure genetic biodiversity and is calculated using:

Proportionofpolymorphicgeneloci =
Numberofpolymorphicgeneloci ÷ Totalnumberofloci

The higher the proportion, the greater the genetic diversity within the population.

Question 24

What does a high proportion of polymorphic gene loci indicate?

Answer 24

Greater genetic biodiversity within the population.

Question 25

Explain how gel electrophoresis is used to measure genetic biodiversity.

Answer 25

It separates DNA fragments by size using an electric current. The pattern of bands compares DNA samples, revealing variation between individuals.

Question 26

What are the main human activities that decrease biodiversity?

Answer 26

Deforestation, agriculture, and climate change.

Question 27

How does a growing human population reduce biodiversity?

Answer 27

It increases demand for land, housing, and resources, leading to deforestation, pollution, and habitat destruction.

Question 28

What is deforestation and how does it affect biodiversity?

Answer 28

Deforestation is the permanent removal of large forest areas. It reduces tree and animal species, removes food sources and habitats, and forces animals to migrate.

Question 29

Why might deforestation still reduce biodiversity even when reforestation occurs?

Answer 29

Reforestation often involves only one or few species, not restoring original biodiversity levels.

Question 30

How does agriculture reduce biodiversity?

Answer 30

Through deforestation for farmland, removal of hedgerows, use of chemicals, monoculture, and killing of pests.

Question 31

What is monoculture and why is it harmful to biodiversity?

Answer 31

Monoculture is the cultivation of one crop species over a large area, reducing the variety of plant and animal life that can survive there.

Question 32

How do herbicides and pesticides reduce biodiversity?

Answer 32

They kill unwanted species, reducing the variety of insects and animals, and can affect species indirectly through the food chain.

Question 33

Why does removing hedgerows affect biodiversity?

Answer 33

Hedgerows provide habitats for many species. Their removal reduces habitat variety and availability.

Question 34

What are some key findings from the 2007 IPCC report on climate change?

Answer 34

The last 50 years saw a 0.13°C/decade temperature increase. Water vapour in the atmosphere has increased. The global sea level rose by 1.8 mm/year (1993–2003). Average air temperatures have risen in the past 100 years. Snow and ice cover have decreased, contributing to sea-level rise. There are long-term upward trends in precipitation in many regions.

Question 35

How can climate change directly affect biodiversity?

Answer 35

By causing habitat loss (e.g., polar ice melting), shifting species distributions, increasing sea levels, and altering food/water availability.

Question 36

How does global warming impact species' ability to survive?

Answer 36

It may lead to extinction if species can’t migrate or adapt quickly enough. Some may be replaced by others more suited to new conditions.

Question 37

How are insects and pollinators affected by climate change, and why does it matter?

Answer 37

Climate change may kill insect populations or force them to migrate, which can reduce plant pollination and affect plant reproduction.

Question 38

What are the aesthetic reasons for maintaining biodiversity?

Answer 38

Biodiversity enriches lives through natural beauty. Natural environments provide relaxation and inspiration. Landscapes with a variety of flora and fauna are attractive. Ecotourism is enhanced by rich biodiversity.

Question 39

What are the economic reasons for maintaining biodiversity?

Answer 39

Many species have economic value (e.g., food, medicine, materials). Loss of biodiversity can lead to soil depletion and desertification, harming agriculture. Diverse ecosystems support tourism and sustainable industries. Organisms are valuable for genetic engineering and biotechnology. Natural environments can be sources of new medicines. Species loss can affect global economic stability.

Question 40

What are the ecological reasons for maintaining biodiversity?

Answer 40

All organisms are part of food webs; loss of one species affects others. Keystone species play a vital role in maintaining ecosystem structure. Genetic diversity within species is essential for adapting to environmental change. Species interactions (e.g., pollination, seed dispersal) support ecosystem function. Biodiverse ecosystems are more resilient to environmental stress. Maintaining biodiversity prevents habitat destruction and climate disruption.

Question 41

What is the difference between in situ and ex situ conservation, and what are their advantages and disadvantages?

Answer 41

In situ conservation Definition: Protects species within their natural habitats. Examples: National parks, wildlife reserves, marine conservation zones. Advantages: - Maintains natural behaviour and evolutionary adaptations. - Species remain part of their ecosystems and food webs. - Less disruptive than removing organisms. - Generally more cost-effective over the long term. Disadvantages: - May not be enough if habitat is severely damaged or species is critically endangered. - Poaching, disease, and climate change can still pose threats. - Harder to control conditions compared to ex situ methods. Ex situ conservation Definition: Protects species by removing part of the population from a threatened habitat and placing it in a new location. Examples: Zoos, aquaria, botanic gardens, seed banks, cryopreservation. Advantages: - Controlled environment: easier to manage threats like disease, predators. - Species can be bred in captivity to increase population size. - Can safeguard species that no longer survive in the wild. - Useful for education, research, and public awareness. Disadvantages: - Often expensive and resource-intensive. - May reduce genetic diversity due to small captive populations. - Reintroduction into the wild is difficult and not always successful. - Animals may not exhibit natural behaviours in captivity.

Question 42

What are some in situ conservation methods?

Answer 42

Establishing protected areas (e.g., wildlife reserves, marine parks). Controlling or preventing introduction of invasive species. Legal protection for endangered species. Managing habitats to maintain or restore biodiversity. Promoting sustainable land use in surrounding areas.

Question 43

What are examples of ex situ conservation?

Answer 43

Captive breeding in zoos and wildlife parks. Botanic gardens conserving rare plant species. Seed banks storing genetic material for future use. Cryopreservation of gametes, embryos, or seeds. Artificial insemination and IVF for reproduction of endangered animals.

Question 44

What are conservation agreements and how do they contribute to biodiversity conservation?

Answer 44

Conservation agreements are formal initiatives—often international—that promote the protection and sustainable use of biodiversity. They involve collaboration among countries, NGOs, and local authorities. These agreements aim to set legal and practical frameworks to protect species, manage habitats, and promote sustainable development. Key Agreements: CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora): - Aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. - Protects around 35,000 species through various levels of trade restrictions. - Member countries enforce bans or limits on import/export of listed species and their derivatives. - Helps reduce poaching and illegal trafficking. Rio Convention on Biological Diversity (1992 Earth Summit): International treaty with three main goals: - Conservation of biological diversity. - Sustainable use of its components. - Fair sharing of benefits from genetic resources. - Encourages development of national biodiversity strategies and action plans. - Promotes ex situ and in situ conservation and environmental impact assessments. The Countryside Stewardship Scheme (UK-based): - Provides financial incentives to farmers and land managers to look after the environment. - Aims to conserve wildlife habitats, maintain landscape features, and reduce soil erosion and water pollution. - Encourages planting of wildflower strips, hedgerow restoration, and field margins for pollinators. Overall Contribution: - Promote global cooperation in biodiversity protection. - Provide legal backing and enforcement measures. - Help fund conservation programs and research. - Raise awareness and guide sustainable development practices.