Q: What term is used to describe the muscular canal (approximately 10 cm long) that serves as the entrance to the reproductive tract? Read this paragraph and choose the correct option from the provided answers: Vagina The vagina, shown at the bottom of Figure 27.9 and Figure 27.9, is a muscular canal (approximately 10 cm long) that serves as the entrance to the reproductive tract. It also serves as the exit from the uterus during menses and childbirth. The outer walls of the anterior and posterior vagina are formed into longitudinal columns, or ridges, and the superior portion of the vaginacalled the fornixmeets the protruding uterine cervix. The walls of the vagina are lined with an outer, fibrous adventitia; a middle layer of smooth muscle; and an inner mucous membrane with transverse folds called rugae. Together, the middle and inner layers allow the expansion of the vagina to accommodate intercourse and childbirth. The thin, perforated hymen can partially surround the opening to the vaginal orifice. The hymen can be ruptured with strenuous physical exercise, penilevaginal intercourse, and childbirth. The Bartholin's glands and the lesser vestibular glands (located near the clitoris) secrete mucus, which keeps the vestibular area moist. The vagina is home to a normal population of microorganisms that help to protect against infection by pathogenic bacteria, yeast, or other organisms that can enter the vagina. In a healthy woman, the most predominant type of vaginal bacteria is from the genus Lactobacillus. This family of beneficial bacterial flora secretes lactic acid, and thus protects the vagina by maintaining an acidic pH (below 4.5). Potential pathogens are less likely to survive in these acidic conditions. Lactic acid, in combination with other vaginal secretions, makes the vagina a self-cleansing organ. However, douchingor washing out the vagina with fluidcan disrupt the normal balance of healthy microorganisms, and actually increase a woman's risk for infections and irritation. Indeed, the American College of Obstetricians and Gynecologists recommend that women do not douche, and that they allow the vagina to maintain its normal healthy population of protective microbial flora. Choices: - uterus - cervix - urethra - vagina A:
vagina

Q: There are a series of rules for naming branched alkanes (and, ultimately, for all organic compounds). these rules make up the system of nomenclature for naming what? Read this paragraph and choose the correct option from the provided answers: Not all hydrocarbons are straight chains. Many hydrocarbons have branches of C atoms attached to a chain. These branched alkanes are isomers of straight-chain alkanes having the same number of C atoms. However, they are different compounds with different physical and chemical properties. As such, they need different names. How do we name branched hydrocarbons? There are a series of rules for naming branched alkanes (and, ultimately, for all organic compounds). These rules make up the system of nomenclature for naming organic molecules. Worldwide, the International Union of Pure and Applied Chemistry (IUPAC) has developed the system of nomenclature for organic compounds. So these rules are sometimes called the IUPAC rules of nomenclature. By learning and applying these rules, you can name any organic compound when given its structure or determine the unique structure of a molecule from its name. You have already learned the basics of nomenclaturethe names of the first 10 normal hydrocarbons. Here, we will add some steps to the procedure so you can name branched hydrocarbons. First, given the structure of an alkane, identify the longest continuous chain of C atoms. Note that the longest chain may not be drawn in a straight line. The longest chain determines the parent name of the hydrocarbon. For example, in the molecule. Choices: - non-organic molecules - typical molecules - oxygen molecules - organic molecules A:
organic molecules

Q: The purpose of scientific investigations generally is to test a what? Read this paragraph and choose the correct option from the provided answers: Although this cartoon pokes fun at scientific hypotheses, the concept of hypothesis is one of the most important in science. Scientific investigations discover evidence that helps science advance, and the purpose of scientific investigations generally is to test hypotheses. Finding evidence to support or disprove hypotheses is how science advances. Choices: - theory - question - suggestion - hypothesis A:
hypothesis

Q: Why wouldn't a teakettle have an aluminum handle? Read this paragraph and choose the correct option from the provided answers: This teakettle is made of aluminum except for its handle, which is made of plastic. Aluminum is a good conductor of heat. It conducts heat from the flames on the range to the water inside the kettle, so the water heats quickly. Plastic, on the other hand, is not a good conductor of heat. It stays cool enough to touch even when the rest of the teakettle becomes very hot. Choices: - it absorbs light - it isn't washable - it is magnetic - it conducts heat A:
it conducts heat