Answer the following question given this paragraph: The mouth also begins the process of mechanical digestion. Sharp teeth in the front of the mouth cut or tear food when you bite into it (see Figure below ). Broad teeth in the back of the mouth grind food when you chew. Food is easier to chew because it is moistened by saliva from the salivary glands. The tongue helps mix the food with saliva and also helps you swallow. After you swallow, the chewed food passes into the pharynx. Q: Teeth in the back of the mouth are used for what? Choices: - swallowing food - tearing food - cutting food - grinding food A:
grinding food

Answer the following question given this paragraph: 26.1 Physics of the Eye The eye is perhaps the most interesting of all optical instruments. The eye is remarkable in how it forms images and in the richness of detail and color it can detect. However, our eyes commonly need some correction, to reach what is called "normal" vision, but should be called ideal rather than normal. Image formation by our eyes and common vision correction are easy to analyze with the optics discussed in Geometric Optics. Figure 26.2 shows the basic anatomy of the eye. The cornea and lens form a system that, to a good approximation, acts as a single thin lens. For clear vision, a real image must be projected onto the light-sensitive retina, which lies at a fixed distance from the lens. The lens of the eye adjusts its power to produce an image on the retina for objects at different distances. The center of the image falls on the fovea, which has the greatest density of light receptors and the greatest acuity (sharpness) in the visual field. The variable opening (or pupil) of the eye along with chemical adaptation allows the eye to detect light intensities from the 10 lowest observable to 10 times greater (without damage). This is an incredible range of detection. Our eyes perform a vast number of functions, such as sense direction, movement, sophisticated colors, and distance. Processing of visual nerve impulses begins with interconnections in the retina and continues in the brain. The optic nerve conveys signals received by the eye to the brain. Q: What conveys signals received by the eye to the brain? Choices: - motor nerve - sciatic nerve - sensory nerve - optic nerve A:
optic nerve

Answer the following question given this paragraph: There are many blood vessels in the kidneys ( Figure above ). The kidneys remove urea and other wastes from the blood through tiny filtering units called nephrons. Nephrons ( Figure below ) are tiny, tube-shaped structures found inside each kidney. Each kidney has up to a million nephrons. Each nephron collects a small amount of fluid and waste from a small group of capillaries. Q: What are the tiny, tube-shaped structures found inside a kidney called? Choices: - neurons - jejunum - dendrites - nephrons A:
nephrons

Answer the following question given this paragraph: Proteins are an essential part of all organisms. They play many roles in living things. Certain proteins provide a scaffolding that maintains the shape of cells (structural proteins). Proteins also make up the majority of muscle tissues. Many proteins are enzymes that speed up chemical reactions in cells. Enzymes interact with the substrates (reactants) of a biochemical reaction, helping the reaction proceed at a much faster rate. Other proteins are antibodies that protect you from pathogens. Antibodies bond to foreign substances in the body and target them for destruction. Still other proteins help carry messages or materials in and out of cells (transport proteins) or around the body. For example, the blood protein hemoglobin (see Figure below ) bonds with oxygen and carries it from the lungs to cells throughout the body. Q: What type of protein speeds up chemical reactions in cells? Choices: - hemoglobin - lipids - collagen - enzyme A:
enzyme