Question

Which of the following statements accurately describe the characteristics of lake ecosystems?

1. Lake ecosystems, unlike lotic ecosystems, are characterized by static water bodies.
2. Light penetration in lakes is consistently uniform throughout the water column.
3. Dissolved oxygen levels in lakes are typically higher than in lotic systems due to greater surface area contact with air.
4. Vertical zonation in lakes is primarily influenced by variations in temperature, sunlight, and dissolved oxygen.

• A. i only
• B. i, iii
• C. All
• D. i, iv

Answer 1

Answer:

D. i, iv

• The environment of static waters of lakes and ponds sharply contrasts with those of lotic ecosystems.

• Light penetration in lakes is usually up to a certain depth which is affected by turbidity.

• Temperature and dissolved oxygen also vary with depth.

• Dissolved oxygen in stagnant water is generally less compared to lotic systems because only a relatively small surface of the water body is indirect contact with air.

• Decomposition of organic matter usually takes place at the bottom of the lake.

• The oxygen content usually decreases with depth.

• The gradations of temperature, sunlight and oxygen are directly responsible for vertical zonation or stratification. occurring in lakes.