The primary source of stem thickening in plants is the vascular cambium. It is a plant tissue located between the phloem and the xylem and in the root of a vascular plant. It is the source of secondary growth or the radial growth of the stem of a plant.
The answer should be agriculture.
Agriculture means farming of crops or the rearing of animals, either for their own use or for commercial purposes. Rural area means a place away from the city, opposite of urban areas, with little buildings and most likely have a smaller population.
On the other hand, construction and manufacturing most likely is going to be common in urban area, as urban area is more likely to have more buildings being built and most of the products are made in the factories in urban areas. Therefore, the only activity that is almost practiced exclusively in rural area is agriculture. Urban areas don't have much space and well environment for agriculture activities.
Agriculture activities can be energy consuming as some may require different machines to help with farming processes such as harvesting or irrigation.
The answer is 300 joules of energy.
An energy pyramid is a presentation of the trophic levels in an ecosystem. Energy from the sun is transferred through the ecosystem by passing through various trophic levels. Roughly 10% of the energy is transferred from one trophic level to the next, thus preventing a large number of trophic levels.
Answer: Option A.
Charles Darwin proposed the theory of natural selection as a mechanism of evolution.
Explanation:
Charles Darwin was an English naturalist that lived between 1809 and 1882. He proposed a theory of evolution and natural selection. The theory states that all living organisms came from and develop through the natural selection of small, inherited variation that increase individual's ability to compete, survive and reproduce.