Sustainable use is often defined as the use of natural resources at a rate that meets the needs of the present human population but which also allows future generations to use the resource to meet their needs. Which of these BEST illustrates the concept of sustainable use? A) Crops are rotated in a farmers field to maximize grain yields. B) A fishing trawler use a large net to catch a school of small fish. C) A logging company reseeds and replants in a forested area after cutting down trees for timber. D) Coal is mined using underground tunnels to avoid the destruction of surface soils by strip mining. algae → water flea → small fish → big fish Use the food chain to answer the question. What would MOST LIKELY happen to the population of the water flea if the algae decreased? A) It would increase. B) It would decrease. C) It would not change. D) It would first increase, then decrease.

1. In a sustainable practice, resources are used judicially to fulfill the current demand and also preserved for catering the demand of future generation. The overall objective is to save resources.

In crop rotation, the agricultural field is used effectively by growing crops with alternate nutrients and mineral demand. Also this saves the soil from getting eroded and allows the land to replenish its lost minerals and nutrients.

Hence, option A is correct

2.

This is a linear food chain and as per the sequence given in question it is clear that water fleas feed upon algae. Thus, if population of algae reduces, the population of water fleas will also decrease.

Option B is correct