PLEASE HELP ME :) In addition to natural factors, human activity can also alter ecosystems. Conduct research on a human activity that currently affects or can theoretically affect your chosen ecosystem. Use your food web model to explain how this change can affect the competition for food resources.

structure is maintained and sustained by:

-cytoskeleton: gives cells coherence

-cell wall: support

-cytoplasm: shape

hope this .

your answer is "the 1950's"

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.