Answer the following question given this paragraph: Centrioles are rod-like structures made of short microtubules. Nine groups of three microtubules make up each centriole. Two perpendicular centrioles make up the centrosome . Centrioles are very important in cellular division, where they arrange the mitotic spindles that pull the chromosome apart during mitosis. Q: What are the rod-like structures made of short microtubules that play an important part in cellular division? Choices: - cilia - mitochondria - fibrils - centrioles A:
centrioles
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Answer the following question given this paragraph: The Mucosal Immune Response Mucosal tissues are major barriers to the entry of pathogens into the body. The IgA (and sometimes IgM) antibodies in mucus and other secretions can bind to the pathogen, and in the cases of many viruses and bacteria, neutralize them. Neutralization is the process of coating a pathogen with antibodies, making it physically impossible for the pathogen to bind to receptors. Neutralization, which occurs in the blood, lymph, and other body fluids and secretions, protects the body constantly. Neutralizing antibodies are the basis for the disease protection offered by vaccines. Vaccinations for diseases that commonly enter the body via mucous membranes, such as influenza, are usually formulated to enhance IgA production. Immune responses in some mucosal tissues such as the Peyer's patches (see Figure 21.11) in the small intestine take up particulate antigens by specialized cells known as microfold or M cells (Figure 21.27). These cells allow the body to sample potential pathogens from the intestinal lumen. Dendritic cells then take the antigen to the regional lymph nodes, where an immune response is mounted. Q: What type of tissues are major barriers to the entry of pathogens into the body? Choices: - skin - vascular - nasal - mucosal A:
mucosal
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Answer the following question given this paragraph: Hypersecretion by an endocrine gland is often caused by a tumor. For example, a tumor of the pituitary gland can cause hypersecretion of growth hormone. If this occurs in childhood, it results in very long arms and legs and abnormally tall stature by adulthood. The condition is commonly known as gigantism (see Figure below ). Q: A tumor of what gland can cause hypersecretion of growth hormone? Choices: - tissues gland - Pancreas - Parathyroid - pituitary gland A:
pituitary gland
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Answer the following question given this paragraph: Hydrocarbons are extremely important to modern life. Their most important use is as fuels. Hydrocarbons are also used to manufacture many products including plastics. The main source of hydrocarbons is fossil fuels. Q: What is the main source of hydrocarbons? Choices: - photosynthesis - greenhouse gases - decomposers - fossil fuels A:
fossil fuels
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