Fusarium wilt is a fungal disease of bananas that can spread quickly through a banana population. The table shows the area affected by Fusarium wilt over time in one country.
What was the percentage increase in the area affected with Fusarium wilt from 1976 to 1999?
A) 40%
B) 60%
C) 150%
D) 250%
▶️ Answer/Explanation
Ans: C
To calculate the percentage increase:
- Initial value (1976): 20,000 hectares
- Final value (1999): 50,000 hectares
- Increase: 50,000 – 20,000 = 30,000 hectares
- Percentage increase: (30,000 / 20,000) × 100 = 150%
The area affected by Fusarium wilt increased by 150% from 1976 to 1999, making C the correct answer.
The graph shows the population of yeast over a period of time.
Which phase shows when the number of yeast cells dying is equal to the number of new yeast cells being produced?
▶️ Answer/Explanation
Ans: C
The stationary phase (C) occurs when the population growth levels off, indicating that the rate of cell division equals the rate of cell death. This happens due to limited resources and accumulation of waste products. The earlier exponential phase (B) shows rapid growth, while the decline phase (D) occurs when deaths exceed new cell formation.
The graph’s plateau at phase C visually represents this equilibrium between cell production and death.