Answer the following question given this paragraph: During anaphase I the spindle fibers shorten, and the homologous chromosome pairs are separated from each other. This occurs as the chiasmata are severed, pulling homologous chromosomes apart. One chromosome from each pair moves toward one pole, with the other moving toward the other pole, resulting in a cell with 23 chromosomes at one pole and the other 23 at the other pole. Each chromosome still contains a pair of sister chromatids; the sister chromatids remain attached at the centromere. Q: How many pairs of chromosomes are there? Choices: - 16 - 25 - 24 - 23 A:
23
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Answer the following question given this paragraph: Proteins play many important roles in living things. Some proteins help cells keep their shape, and some make up muscle tissues. Many proteins speed up chemical reactions in cells. Other proteins are antibodies, which bind to foreign substances such as bacteria and target them for destruction. Still other proteins carry messages or materials. For example, human red blood cells contain a protein called hemoglobin, which binds with oxygen. Hemoglobin allows the blood to carry oxygen from the lungs to cells throughout the body. A model of the hemoglobin molecule is shown in Figure below . Q: What type of proteins bind to foreign substances and attempt destruction? Choices: - membranes - ribosomes - antigens - antibodies A:
antibodies
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Answer the following question given this paragraph: Competition is a relationship between organisms that strive for the same resources in the same place. The resources might be food, water, or space. There are two different types of competition:. Q: What is a relationship between organisms that strive for the same resources in the same place? Choices: - antagonistic - symbiotic - parasitic - competition A:
competition
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Answer the following question given this paragraph: Parasympathetic Division of the Autonomic Nervous System The parasympathetic division of the autonomic nervous system is named because its central neurons are located on either side of the thoracolumbar region of the spinal cord (para- = "beside" or "near"). The parasympathetic system can also be referred to as the craniosacral system (or outflow) because the preganglionic neurons are located in nuclei of the brain stem and the lateral horn of the sacral spinal cord. The connections, or "circuits," of the parasympathetic division are similar to the general layout of the sympathetic division with a few specific differences (Figure 15.4). The preganglionic fibers from the cranial region travel in cranial nerves, whereas preganglionic fibers from the sacral region travel in spinal nerves. The targets of these fibers are terminal ganglia, which are located nearor even withinthe target effector. These ganglia are often referred to as intramural ganglia when they are found within the walls of the target organ. The postganglionic fiber projects from the terminal ganglia a short distance to the target effector, or to the specific target tissue within the organ. Comparing the relative lengths of axons in the parasympathetic system, the preganglionic fibers are long and the postganglionic fibers are short because the ganglia are close toand sometimes withinthe target effectors. The cranial component of the parasympathetic system is based in particular nuclei of the brain stem. In the midbrain, the EdingerWestphal nucleus is part of the oculomotor complex, and axons from those neurons travel with the fibers in the oculomotor nerve (cranial nerve III) that innervate the extraocular muscles. The preganglionic parasympathetic fibers within cranial nerve III terminate in the ciliary ganglion, which is located in the posterior orbit. The postganglionic parasympathetic fibers then project to the smooth muscle of the iris to control pupillary size. In the upper medulla, the salivatory nuclei contain neurons with axons... Q: The parasympathetic system can also be referred to as the what? Choices: - badolato system - digestive system - lentivirus system - craniosacral system A:
craniosacral system
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