what evidence is there to show that changing sand to glass is a chemical change

Which ideas did your answer contain? check all that apply. no food for organisms no oxygen in the atmosphere no trees or flowering plants no products based on trees or plants (building materials, medicines, fuels, fibers) no fossil fuels

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

What is the main function of the central vacuole in a plant cell? a. absorbs energy from the sun to produce food b. holds water and maintains turgor pressure c. breaks down molecules to release energy d. contains the cell's genetic material