Answer the following question given this paragraph: Normal light microscopes can magnify objects up to about 1,500 times. Electron microscopes can magnify objects up to 1,000,000 times. Why can electron microscopes magnify images so much? A microscope's resolution depends on the wavelength of light used. The smaller the wavelength, the more a microscope can magnify. Light is a wave, and, as such, it has a wavelength associated with it. The wavelength of visible light, which is detected by the eyes, varies from about 700 nm to about 400 nm. One of the startling conclusions about modern science is that electrons also act as waves. However, the wavelength of electrons is much, much shorterabout 0.5 to 1 nm. This allows electron microscopes to magnify 600700 times more than light microscopes. This allows us to see even smaller features in a world that is invisible to the naked eye. Atoms act the way they do because of their structure. We already know that atoms are composed of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus, and electrons orbit around the nucleus. But we need to know the structural details to understand why atoms react the way they do. Virtually everything we know about atoms ultimately comes from light. Before we can understand the composition of atoms (especially electrons), we need to understand the properties of light. Q: While normal light microscopes can magnify objects up to about 1,500 times, what advanced instruments can magnify objects up to 1,000,000 times? Choices: - magnetic microscopes - micro microscopes - electric microscopes - electron microscopes A:
electron microscopes

Answer the following question given this paragraph: Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. Q: What normal bodily occurrence can cause skeletal muscles to involuntarily contract? Choices: - thinking - movement - respiration - reflexes A:
reflexes

Answer the following question given this paragraph: Life probably began in the oceans. No one knows exactly how or when. Life may have originated more than once. If life began before the Moon formed, that impact would have wiped it out. Then life would have had to originate again. Eventually conditions on Earth became less violent. The planet could support life. Q: Life probably began where? Choices: - rocks - the Sun - caves - oceans A:
oceans

Answer the following question given this paragraph: Nucleic acids consist of chains of small molecules called nucleotides, which are held together by covalent bonds. The structure of a nucleotide is shown in the Figure below . Each nucleotide consists of:. Q: Chains of small molecules called nucleotides make up what? Choices: - chromosomes - peptides - proteins - nucleic acids A:
nucleic acids