Answer:
The rift valley formed when the crust pulled apart.
Explanation:
The statement that best describes how the Great Rift Valley in Africa formed is that they formed when the crust pulled apart.
- This is geologically known as divergence.
- The Arabian plate and the Nubian/Somali plate are divergent plates.
- They are currently moving apart and away from each other.
- This creates a crack on the earth which is what formed the rift valley in Africa.
- Along such margins, earthquake activities are prominent.
Answer: 1. Sea urchins and sea otters
2. They are prey for carnivores.
3. Sea otters, star fish
Explanation:
Sea urchins and sea otters are carnivores as they eat on the flesh of starfish and sea urchins respectively.
Starfish feed on the kelp forests which are the producers in the food chain and the starfish is the primary consumer and prey for sea urchins. So, starfish and kelp forests are the prey in the marine ecosystem.
Keystone species is the one which controls the population of other inferior species in an ecosystem. Here, sea otters consume sea urchins so the population of sea urchins remained in control Starfish controls the population of kelp forest.
Answer:
water is an abiotic factor
Answer:
Noble gases
Explanation:
Because they're stable or rather they're unreactive.