Question

short answer

1. describe how a stream changes as it moves from its source toward the ocean.
2. describe two adaptations of animals to the desert environment.
3. are wetlands always wet? explain.
4. explain how the salt content in an estuary changes constantly.

Explanation:

1. As a stream moves from its source to the ocean, its gradient decreases, velocity slows, channel width and depth increase, and sediment - load characteristics change. It may start as a fast - flowing, narrow channel in the mountains and become a wider, slower - moving body of water near the ocean.
2. One adaptation of animals to the desert environment is having efficient kidneys to conserve water, reducing the amount of water lost in urine. Another is being nocturnal to avoid the intense heat of the day, as temperatures are lower at night which helps in conserving water and energy.
3. Wetlands are not always wet. They can experience periods of dryness depending on seasonal changes, rainfall patterns, and water - management activities. Some wetlands may dry up completely during the dry season and then refill during the wet season.
4. In an estuary, the salt content changes constantly because it is a transition zone between freshwater (from rivers) and saltwater (from the ocean). Tidal movements bring in saltwater from the ocean, while freshwater from rivers continuously flows into the estuary. The balance between the two sources of water varies with tides, river flow rates, and weather conditions.

Answer:

1. Gradient decreases, velocity slows, channel width/depth increase, sediment - load changes.
2. Efficient kidneys for water conservation; nocturnal behavior to avoid heat.
3. No, they can dry up due to seasonal/rainfall/management factors.
4. Due to the mix of freshwater from rivers and saltwater from tides, with varying flow rates and weather conditions.