The value because it could be worth a lot or a little
Oil, coal, natural gas, metals, stone and sand are natural resources. Other natural resources are air, sunlight, soil and water. Animals, birds, fish and plants are natural resources as well.
Answer:
Biofuels like fuel from microalgae are very costly as compared to fossil fuels.
Explanation:
The cost of biofuels is too high as compared to that of fossil fuel. For instance,
the cost of 1 gallon of algal fuel is $32.81 per gallon while cost of diesel is $2.9 -3.2 per gallon.
However, biofuels are very environment friendly as compared to that of fossil fuels.
If a zebra mussel is discovered in a lake in Pennsylvania, then the ecologist would be worried because it is an invasive species. The zebra mussel is native to Ukraine and Russia, but if it has been found in Pennsylvania, than it means that it has been introduced in this area. As an invasive species, the zebra mussel can be very dangerous for the native species in the lake. The invasive species usually are more competitive for food sources than the native species, manage to reproduce quicker, bring in diseases, and the native species tend to not have defense mechanisms for them. This leads to rapid decline or even extinction in the native species, while the invasive spreads out quickly and takes over, resulting in dramatic change in the whole ecosystem.