The whole human body is a lever system, that's how muscle work. Your joins are the fulcrum, your muscle contracts and hence is the effort. On the other side, whatever you're holding and the weight of your hand is the load. There are all 3 classes of lever system in your body.
Almost all the energy in ecosystems comes from the sun.<span>Energy is captured by producers and then passed in a linear progression from one trophic level to the next. At each level, much of the energy escapes the ecosystem as heat. Unlike this one-way flow of energy, matter is recycled within and between ecosystems. Elements pass from one organism to another and among parts of the non-living environment through closed loops called biogeochemical cycles.</span>
Answer:
i. (answer is in the file I attached)
ii. underground parts of the plants are thick , fleshy and swollen because they store food in the form of starch.
iii. Spines that have been converted into leaves. These prevent water loss by reducing surface area. The spines help defend the cacti from predatory animals. To decrease water loss due to evaporation, the cuticle is very thick and waxy.
iv. this plant is called a water lettuce it's leaves are modified to form modified to form hydrophyte They are aquatic plants that have evolved to thrive in water. This is capable of comprehending with aquatic macrophyte, which will be entirely submerged in water and in some circumstances allowed to float on the water's surface.
hope this helps :)