Answer the following question given this paragraph: saliva. Although there may be a tendency to think that mechanical digestion is limited to the first steps of the digestive process, it occurs after the food leaves the mouth, as well. The mechanical churning of food in the stomach serves to further break it apart and expose more of its surface area to digestive juices, creating an acidic "soup" called chyme. Segmentation, which occurs mainly in the small intestine, consists of localized contractions of circular muscle of the muscularis layer of the alimentary canal. These contractions isolate small sections of the intestine, moving their contents back and forth while continuously subdividing, breaking up, and mixing the contents. By moving food back and forth in the intestinal lumen, segmentation mixes food with digestive juices and facilitates absorption. In chemical digestion, starting in the mouth, digestive secretions break down complex food molecules into their chemical building blocks (for example, proteins into separate amino acids). These secretions vary in composition, but typically contain water, various enzymes, acids, and salts. The process is completed in the small intestine. Food that has been broken down is of no value to the body unless it enters the bloodstream and its nutrients are put to work. This occurs through the process of absorption, which takes place primarily within the small intestine. There, most nutrients are absorbed from the lumen of the alimentary canal into the bloodstream through the epithelial cells that make up the mucosa. Lipids are absorbed into lacteals and are transported via the lymphatic vessels to the bloodstream (the subclavian veins near the heart). The details of these processes will be discussed later. In defecation, the final step in digestion, undigested materials are removed from the body as feces. Q: Mechanical churning of food in what organ serves to further break it apart and expose more of its surface area to digestive juices, creating an acidic "soup" called chyme? Choices: - liver - kidneys - gall bladder - stomach A:
stomach
Answer the following question given this paragraph: Sponges come in a variety of shapes and sizes. For example, they may be shaped like tubes, fans, cones, or just blobs. They range in diameter from about a centimeter (0.4 inches) to over a meter (3.3 feet). Many species live in colonies that may be quite large. Adult sponges are sessile. This means they are unable to move from place to place. Root-like projections anchor them to solid surfaces such as rocks and reefs. Q: Root-like projections anchor adults of what colony-dwelling animals to solid surfaces such as rocks and reefs? Choices: - anemones - corals - molluscs - sponges A:
sponges
Q: Answer the following question given this paragraph: Q: How many mass distinctions have radically altered the history of life? Choices: - six - one - four - five A:
A: five
Question: Answer the following question given this paragraph: All of the examples of potential energy described above involve movement or the potential to move. The form of energy that involves movement is called mechanical energy. Other forms of energy also involve potential energy, including chemical energy and nuclear energy. Chemical energy is stored in the bonds between the atoms of compounds. For example, food and batteries both contain chemical energy. Nuclear energy is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. Nuclei of radioactive elements such as uranium are unstable, so they break apart and release the stored energy. Q: What is the type of energy that involves movement? Choices: - molecular energy - thermal energy - light energy - mechanical energy A:
Answer: mechanical energy
*Question*
Answer the following question given this paragraph: Electric current is measured in coulombs per second, or amperes. Q: Electric current is measured in coulombs per second, also called what? Choices: - voltages - joules - watts - amperes A:
**Answer**
amperes
*Question*
Answer the following question given this paragraph: Mechanical Digestion in the Small Intestine The movement of intestinal smooth muscles includes both segmentation and a form of peristalsis called migrating motility complexes. The kind of peristaltic mixing waves seen in the stomach are not observed here. If you could see into the small intestine when it was going through segmentation, it would look as if the contents were being shoved incrementally back and forth, as the rings of smooth muscle repeatedly contract and then relax. Segmentation in the small intestine does not force chyme through the tract. Instead, it combines the chyme with digestive juices and pushes food particles against the mucosa to be absorbed. The duodenum is where the most rapid segmentation occurs, at a rate of about 12 times per minute. In the ileum, segmentations are only about eight times per minute (Figure 23.20). Q: During what in the small intestine do rings of smooth muscle repeatedly contract and then relax? Choices: - mitosis - contraction - compression - segmentation A:
**Answer**
segmentation