Unit 3: Agriculture

How has world hunger increased, decreased, or stayed the same in the last three decades?

Decreased

What was the green revolution of the mid to late 1990’s?

period of agricultural advancements, primarily focused on improving crop yields and food security

Describe the relationship between growth and education.

Education is needed for growth within the industry of agriculture (new technology, decision making, resource management)

What is the main purpose of photosynthesis?

Make sugar

What is the Calvin cycle, and what time of the day does it occur?

Uses ATP, NADPH, and CO2 to make sugar. Dependent on light reactions so must happen during the day when the sun is out

Why do roots still need oxygen, and how do aquatic plants like water lilies get oxygen to their roots?

For respiration to produce energy, aquatic plants use special air channels to get oxygen to its roots

What is photorespiration, when does it occur, and why is it a problem?

rubisco uses O2 instead of CO2, occurs when oxygen is high and carbon dioxide is low, problem because it wastes energy and carbon

Why would C4 crops potentially be a better choice for locations with hotter growing seasons?

They can be much more drought resistant compared to non C4 crops

Why does plant growth slow or stop when plants are water stressed? Include the role the stomata plays.

When plants are water stressed the stomata is closed to prevent water loss. This reduces the intake of CO2 needed for photosynthesis and growth can be impacted

Why do plants need mineral nutrients like phosphorus?

It is a key component of ATP which is large energy contributor

Why do white rice and white bread have less nutritional value han brown rice and whole grain bread?

“White” products use just the endosperm and not the whole grain which includes the embryo

What is golden rice, and why is there pushback against it?

genetically modified variety of rice engineered to produce beta-carotene, raises concerns about GMOs and their potential impacts on the environmental and human health

Describe the symbiotic relationship between rhizobia and legumes. What resource does each organism offer to the other? Why is this useful for agriculture?

Rhizobia receives sugar, legumes receives nitrogen. Reduces the need for nitrogen fertilizers

Why was George Washington Carver’s idea for cotton farmers to grow peanuts such a brilliant idea?

Improved farmer protein intake and revolutionized agricultural economy

Explain why the allowing crops to become somewhat stressed can improve their nutritional value.

Can add nutritional value by production of secondary metabolites, such as antioxidants

Describe one agricultural practice that contributed to the Dust Bowl.

Extensive plowing

Describe the A,B, and C soil horizons

A: (TOPSOIL) nutrient rich w/ biological matter

B: (SUBSOIL) leached from horizon A and little to no organic matter

C: (PARENT MATERIAL) rock from A + B

Why does soil particle size matter for soil quality?

Sand drains water and clay doesn’t drain as well. Different plants have different needs

Why does leaving behind dead matter or adding dead plant matter such as mulch a good idea a soil fertility?

gradually decomposes and releases essential nutrients back into the soil

Describe two pros and cons of hydroponics.

Pros:

• Eliminates the need for soil

• Provides a controlled environment, leading to improved yields.

Cons

• High initial setup and operational costs.

• Requires constant monitoring and technical expertise.

What is aquaponics?

System that is mutually beneficial as fish waste provides nutrients for plants, while plants help filter and purify water for the fish

What is the difference between mobile and immobile nutrients? How would you be able to tell whether a plant is deficient or nutrient, as opposed to being deficient in an immobile nutrient?

Mobile nutrients can move immobile can’t. Mobile nutrient deficiencies show up in old leaves opposed to new, immobile nutrient deficiencies show up in new leaves first

Why is it a good idea for farmers to send their soil for nutrient testing?

Allows for precise fertilization techniques and an overall increase in efficiency

Is it possible to fertilize a plant to much? Explain why.

Yes, over-fertilizing can harm plants by causing salt buildup, leading to root damage and a lack of water uptake

Why do agricultural fields need fertilizer so much more than natural ecosystems like forests?

The crops are harvested, removing nutrients. Forests can recycle nutrients

What is the Harbor-Bosch process, why does it contribute to greenhouse gas emissions, and why do we need to perform it on such a large scale?

Uses high temperatures and pressure to provide Nitrogen in fertilizer, Nitrogen is widely used and needed

What is eutrophication, how is it linked to use fertilizers, and what can farmers do to decrease it?

Excessive enrichment of water bodies with nutrients, usually caused by runoff from fertilizers, reducing fertilizer and practicing sustainable practices

Describe two principles of integrated pest management (IPM).

Biological Control - preventing predators and parasites

Mechanical Control - physically removing the pests

Why is IPM a more sustainable option than spraying on a schedule?

reduces chemical use by targeting specific pests only when necessary

Explain why controlling weeds is more important than a layperson might think?

weeds compete with crops for nutrients, water, and light, which can dramatically reduce yields

Pick TWO pesticides and describe them. Make sure you include the type of pest they target and how toxic they are for humans

Chlorpyrifos - attacks central nervous system insects like mosquitoes and termites, potential toxic effects in humans especially affecting children’s development

Neem Oil - affects insects hormones but doesn’t harm bee’s or ladybugs, children should not consume neem oil

Describe one method that an organic farmer could use to address a serious insect infestation, explain why the method is a good idea.

Sulfur, doesn’t use fertilizers or pesticides but it is a good organic farming insecticide that is very effective (CHECK)

Describe one method that an organic farmer could use to address a very mild insect infestation, and explain why that method is a good idea.

Insecticidal Soaps - effective against soft-bodied insects and have minimal environmental impact, preserving beneficial insects and can be used in organic farming (CHECK)

Pick one plant family, describe one visible trait you could use to recognize a plant as belonging to that family, and name a crop plant from that family.

Poaceae Family (Grasses), not woody, wheat

Why was dwarf or semi-dwarf wheat an important part of the Green Revolution?

shorter stature allowed plants to support heavier yields without falling over leading to increased food production

Why do people say that plant based diets are more sustainable?

fewer resources, such as water and land, and result in lower greenhouse gas emissions

Why is it someone problematic to use repeat asexual reproduction to produce crop plants?

Lack of gene diversity, making plants more susceptible to diseases and pests

How does genetic diversity make agricultural production more resistant to diseases?

enhances disease resistance by ensuring that not all plants are susceptible to a common cause

Why is asexual reproduction sometimes very useful in agriculture?

Ensures consistency and predictable traits

Why are apple trees often grafted by putting the branch of one tree onto the trunk of an other tree?

ensure they produce high-quality fruit while benefiting from the root’s desirable traits (disease resistance)

Describe selective breeding.

process of choosing specific plants or animals with desirable traits to reproduce which makes better genes for future generations

Why is CRISPR-Cas9 a huge improvement over older methods of genetic engineering?

Cuts DNA more precise, allows scientists to edit specific genes

What is one pro and one con of Roundup Ready crops?

Pro: allows farmers to use herbicides without harming the crop

Con: overuse of Roundup has led to herbicide-resistant weeds

What are Bt crops, and why are many organic farmers upset about their use?

Produce the toxins that Bt naturally produces, Insects are becoming Bt resistant and organic farmers can fight off insects

What is one way that rice could be genetically modified to either increase production or make it more sustainable?

Rice could be genetically modified to require less water by improving drought resistance

Use the example of nitrogen-fixing corn to explain why existing genetic variation in crop plants is so useful.

N-fixing corn can make its own nitrogen from the air. This ultimately reduces the need for synthetic fertilizers (CHECK)

What are seedbanks and why are they helpful?

Seedbanks store genetic material from diverse plant species to preserve biodiversity incase of “emergencies” (climate change)

Describe one method farmers can use to preserve or increase their soil health.

Crop rotation, helps prevent pest buildup and diversify nutrients

Describe one method farmers can use to conserve water in agriculture.

Drip irrigation delivers water directly to plant roots, reducing water waste

Describe one method farmers can use to reduce pollution from agriculture.

Fertilize only where/when necessary

Describe one method farmers can use to leverage diversity to improve the sustainability of agriculture.

Plant diverse crops

Describe one way that consumers (e.g., people shopping at grocery stores) can improve sustainability of agriculture, by modifying the way they buy food.

Can by locally to eliminate pollution that occurs from long distance shipping of food

Describe THREE ways that we can use plant science to make agriculture more productive or more sustainable.

1. Developing drought-resistant crops

2. Improving soil so you don’t have to rely on fertilizers.

3. Using precision breeding techniques like CRISPR allows for improvements in crop disease resistance