Lecture 10 Flashcards
Which of the following is NOT considered a component of agrobiodiversity?
A. Domesticated plants and animals
B. Soil micro-organisms
C. Fossil fuels
D. Crop wild relatives
C. Fossil fuels
Explanation: Agrobiodiversity includes domesticated species, their wild relatives, and interacting species but does not include non-biological resources like fossil fuels.
What percentage of global calories is provided by just three crop species (rice, maize, and wheat)?
A. 30%
B. 50%
C. 70%
D. 90%
B. 50%
Explanation: These three species dominate global calorie supply, underscoring the reliance on limited crop diversity.
Which of the following traits is commonly associated with domestication?
A. Increased seed shattering
B. Enhanced thorns
C. Larger seeds
D. Higher dormancy rates
C. Larger seeds
Explanation: Domestication often results in traits that increase yield and harvestability, such as larger seeds.
Which type of conservation focuses on maintaining genetic integrity in natural habitats?
A. In situ conservation
B. Ex situ conservation
C. Seed vault preservation
D. Genetic modification
A. In situ conservation
Explanation: In situ conservation occurs in natural habitats, allowing species to evolve under natural conditions.
What is the “Jevons Paradox” in the context of agricultural intensification?
A. Intensification leads to reduced environmental impact.
B. Increased efficiency results in greater overall resource use.
C. Intensification guarantees biodiversity preservation.
D. Increased crop diversity leads to uniform ecosystems.
B. Increased efficiency results in greater overall resource use.
Explanation: The paradox suggests that efficiency gains can lead to increased demand and resource use.
Define “crop wild relatives” (CWRs) and explain their importance.
CWRs are wild plant species genetically related to domesticated crops. They are crucial for agriculture as they provide genetic traits like disease resistance and climate adaptability.
Describe two major challenges associated with ex situ conservation of agrobiodiversity.
High costs of collection and maintenance.
Genetic drift and inbreeding due to small population sizes.
What is the difference between land sparing and land sharing strategies in agriculture?
Land sparing separates areas for intensive agriculture and conservation.
Land sharing integrates biodiversity conservation into agricultural landscapes.
How does climate change pose a threat to agrobiodiversity?
It alters ecosystems, increasing stress on species and reducing genetic diversity, making crops more vulnerable to pests, diseases, and changing conditions.
Explain the term “domestication syndrome.”
The set of traits selected during domestication to enhance crop yield, harvestability, and edibility, often leading to reduced genetic diversity.
Why are Vavilov centers important in understanding agrobiodiversity?
These regions are hotspots of genetic diversity and the original sites of domestication, critical for conserving CWRs.
List two ecological services provided by pollinators in agriculture.
Gene dispersal for plants.
Essential pollination for fruit and seed production in crops like cocoa and apples.
What is the significance of arbuscular mycorrhizal fungi (AMF) in agriculture?
AMF improve nutrient uptake, enhance resistance to pathogens, and boost crop production, especially in low-input systems.
Analyze the implications of relying on a few major crop species for global food production.
Dependence on a few crops increases vulnerability to pests, diseases, and climate change, reducing resilience and risking food security.
Evaluate the role of genetic diversity in combating agricultural pests and diseases.
Genetic diversity allows crops to adapt and resist evolving pests and diseases, ensuring sustainable yields and reducing dependency on chemical inputs.
What are the pros and cons of in situ vs. ex situ conservation?
In situ pros: Supports natural evolution and adaptation.
Cons: Land use conflicts and undervaluation of conservation land.
Ex situ pros: Secure preservation in controlled environments.
Cons: Loss of adaptability and high maintenance costs.
Discuss the challenges of integrating sustainable intensification into modern agriculture.
Challenges include balancing yield increases with reducing environmental impact, managing greenhouse gas emissions, and ensuring equitable resource use.
Case Study: The Irish Potato Famine
Question: How did limited genetic diversity in potatoes contribute to the famine, and what lessons does this event provide for agrobiodiversity conservation?
Monocultures of genetically uniform potatoes were highly susceptible to late blight. The famine highlights the need for genetic diversity to reduce crop vulnerability.
Case Study: Use of Solanum bulbocastanum in combating potato blight
Question: Explain how CWR traits were utilized to address potato blight and the significance of such strategies for modern agriculture.
Resistance genes from Solanum bulbocastanum were introduced into cultivated potatoes, showcasing the importance of preserving and using CWRs for crop resilience.
Case Study: Grassy stunt virus in rice
Question: How did crossing Oryza nivara with Oryza sativa help combat the grassy stunt virus, and what does this reveal about the role of CWRs in disease management?
The cross conferred resistance to the virus, illustrating the critical role of CWRs in enhancing crop defenses against emerging threats.
