Chapter 6 Flashcards
What is C4 Photosynthesis?
A photosynthetic pathway common in crop and prairie plants like corn and rice that allows CO₂ to outcompete oxygen due to specialized leaf anatomy.
C4 photosynthesis is especially efficient in hot and dry environments.
What are CAM plants?
Plants that utilize Crassulacean Acid Metabolism, found in desert succulents like cacti, yuccas, aloe vera, and agave.
CAM plants have adapted to conserve water in arid environments.
How do CAM plants manage stomatal behavior?
Stomata are closed during the day to minimize water loss and open at night to take in CO₂.
This adaptation helps CAM plants survive in dry conditions.
What is the carbon footprint of fossil fuels?
Fossil fuels release CO₂ and other pollutants like sulfur dioxide when burned, contributing to environmental degradation.
Fossil fuels are classified as non-renewable due to the extensive formation time.
List types of fossil fuels.
- Coal
- Oil
- Natural gas
These fuels are formed from fossilized remains over millions of years.
What are renewable resources?
- Wind
- Solar power
- Hydroelectric power
- Geothermal energy
These resources can be replenished naturally.
Is nuclear energy considered renewable?
Debated; it’s considered non-renewable due to long-lived waste products despite uranium availability.
The classification of nuclear energy can vary based on interpretation.
How can groundwater be renewable?
When used sustainably, similar to natural water cycles.
Over-extraction can turn groundwater into a non-renewable resource.
What are the primary sources of ethanol?
- Corn
- Soybeans
Ethanol is often used as a biofuel.
Why is ethanol considered greener?
CO₂ released during burning was recently captured by the plants, but includes emissions from cultivation and processing.
The overall environmental impact of ethanol can vary.
What challenges are associated with ethanol production?
- High water and energy inputs
- Negative impacts from fertilizer runoff
- Potential engine damage
These factors can limit the viability of ethanol as a sustainable fuel.
What are the advantages of algae-based biodiesel?
- Grows in water
- Requires fewer resources
- Can utilize wastewater
- Produces lipids directly
Algae biodiesel has the potential to be more efficient than traditional crops.
What environmental concerns are associated with fertilizer use?
- Carbon-intensive production
- Nutrient pollution in waterways
Sustainable practices can mitigate these issues.
What sustainable practices can reduce synthetic fertilizer dependency?
- Crop rotation with legumes
Legumes naturally replenish soil nitrogen, promoting soil health.
How does large-scale farming affect soil nutrients?
It removes nutrients from the soil, unlike natural ecosystems where nutrients are recycled.
This can lead to soil degradation over time.
What is the impact of processing crops like corn into ethanol?
It involves significant carbon emissions and contributes to the overall carbon footprint.
Transportation of agricultural products also adds to emissions.
True or False: Burning fossil fuels releases ancient carbon.
True
This release increases atmospheric CO₂ levels.
True or False: Biodiesel releases recently captured carbon.
True
This helps maintain a balanced carbon cycle.
What is a potential negative effect of ethanol on engines?
It can reduce efficiency and cause potential damage in small engines.
This is particularly true for engines not designed for high ethanol content.
