Unit Test (Solutions): Improvement in Food Resources

Time: 1 hour 
M.M. 30 
Attempt all questions. 
Question numbers 1 to 5 carry 1 mark each. 
Question numbers 6 to 8 carry 2 marks each. 
Question numbers 9 to 11 carry 3 marks each. 
Question numbers 12 & 13 carry 5 marks each.

Q1. What is the main source of carbohydrates in our diet? (1 Mark)

Ans: Cereals

Q2. Name one kharif crop. (1 Mark)

Ans: Paddy

Q3. What is the process of crossing between genetically dissimilar plants called? (1 Mark)

Ans: Hybridisation

Q4. Which type of manure is prepared using earthworms? (1 Mark)

Ans: Vermi-compost

Q5. Name one exotic breed of cattle used for longer lactation periods. (1 Mark)

Ans: Jersey

Q6. Why is irrigation important for agriculture in India? (2 Marks)

Ans: Irrigation is important because:

1. Indian agriculture depends heavily on monsoons.

2. Irrigation provides regular water supply, improves crop yield, and prevents crop failure during droughts.

Q7. Differentiate between mixed cropping and inter-cropping. (2 Marks)

Ans:

• Mixed cropping: Growing two or more crops simultaneously on the same land without a definite pattern, e.g., wheat + gram.
• Inter-cropping: Growing two or more crops simultaneously in a definite row pattern, e.g., soybean + maize, to maximize nutrient use and reduce pest spread.

Q8. What are the two types of food requirements for dairy animals? (2 Marks)

Ans:

• Maintenance Requirement: For basic body functions and keeping the animal healthy.

• Milk Production Requirement: For producing milk during the lactation period.

Q9. How do biotic and abiotic factors affect crop production? (3 Marks)

Ans: Biotic factors such as pests, diseases, and weeds negatively affect crop production by damaging plants, reducing growth, and competing for nutrients. 
Abiotic factors like drought, salinity, floods, extreme heat, or frost cause environmental stress, which hampers plant development and lowers crop yield. 
To overcome these challenges, farmers use crop varieties that are resistant to both biotic and abiotic stresses, helping to maintain and improve agricultural productivity.

Q10. Explain the advantages of composite fish culture. (3 Marks)

Ans: Composite fish culture involves growing five or six fish species together in a pond, such as Catla, Rohu, and Mrigal, each having different feeding habits. This ensures that all zones of the pond-surface, middle, and bottom-are efficiently used without any competition for food. As a result, it leads to better utilization of available resources and significantly increases the overall fish yield.

Q11. What are the desirable traits for improving poultry breeds? (3 Marks)

Ans: 

The desirable traits for improving poultry breeds include:

1. High egg and meat production - Breeds should lay more eggs and provide good-quality meat.

2. Disease resistance - Birds should be able to resist common infections to reduce losses.

3. Adaptability and low maintenance - They should adjust well to different climates, especially heat, and survive on cheap and fibrous feed.
These traits help increase poultry productivity and reduce the cost of poultry farming.

Q12. Explain the methods used for crop variety improvement and their significance. (5 Marks)

Ans:

The two main methods used for crop variety improvement are hybridisation and genetic modification.

• Hybridisation is the process of crossing two genetically different plants to combine desirable traits such as high yield, disease resistance, and improved quality. It can be inter-varietal (between varieties), interspecific (between species), or intergeneric (between genera).

• Genetic Modification (GM) involves inserting specific genes into crops to develop new traits. For example, Bt cotton is genetically modified to resist insect pests.

Significance:
These methods help increase crop production, improve nutritional quality (like more protein in pulses), and make crops resistant to pests, diseases, drought, and other stresses. They also reduce the time crops take to mature and allow them to grow in different climates and regions.

Q13. Compare the use of manure and fertilizers in agriculture, highlighting their impact on soil fertility and the environment. (5 Marks)

Ans:

Manure:

• Composition: Organic matter from decomposed animal excreta and plant waste.
• Benefits: Enriches soil with nutrients, improves soil structure, increases water-holding capacity in sandy soils, and aids drainage in clayey soils.
• Environmental impact: Eco-friendly, recycles farm waste, reduces chemical use.
• Drawback: Supplies nutrients in smaller quantities, slower effect.

Fertilizers:

• Composition: Commercially produced, supply nitrogen, phosphorus, and potassium.
• Benefits: Ensures quick vegetative growth, increases yields in high-cost farming.
• Environmental impact: Excessive use causes water pollution, harms soil microbes, and reduces long-term soil fertility.
• Drawback: Requires careful application to avoid nutrient loss.

Conclusion: 

Manure is better for long-term soil health and sustainability. Fertilizers are useful for quick results but should be used carefully to avoid harming the environment.