Ques:Answer the following question given this paragraph: There is a one problem when using food chains to accurately describe most ecosystems. Even when all organisms are grouped into appropriate trophic levels, some of these organisms can feed on species from more than one trophic level; likewise, some of these organisms can be eaten by species from multiple trophic levels. In other words, the linear model of ecosystems, the food chain, is not completely descriptive of ecosystem structure. A holistic modelwhich accounts for all the interactions between different species and their complex interconnected relationships with each other and with the environmentis a more accurate and descriptive model for ecosystems. A food web is a graphic representation of a holistic, non-linear web of primary producers, primary consumers, and higher-level consumers used to describe ecosystem structure and dynamics (Figure 46.6). Q: A problem with using food chains to describe ecosystems is that some organisms can feed on or be consumed by species from more than one of what level? Choices: - biome level - habitat level - pH level - trophic level A:

Ans:trophic level
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Ques:Answer the following question given this paragraph: The stomach mucosa's epithelial lining consists only of surface mucus cells, which secrete a protective coat of alkaline mucus. A vast number of gastric pits dot the surface of the epithelium, giving it the appearance of a well-used pincushion, and mark the entry to each gastric gland, which secretes a complex digestive fluid referred to as gastric juice. Although the walls of the gastric pits are made up primarily of mucus cells, the gastric glands are made up of different types of cells. The glands of the cardia and pylorus are composed primarily of mucus-secreting cells. Cells that make up the pyloric antrum secrete mucus and a number of hormones, including the majority of the stimulatory hormone, gastrin. The much larger glands of the fundus and body of the stomach, the site of most chemical digestion, produce most of the gastric secretions. These glands are made up of a variety of secretory cells. These include parietal cells, chief cells, mucous neck cells, and enteroendocrine cells. Parietal cellsLocated primarily in the middle region of the gastric glands are parietal cells, which are among the most highly differentiated of the body's epithelial cells. These relatively large cells produce both hydrochloric acid (HCl) and intrinsic factor. HCl is responsible for the high acidity (pH 1.5 to 3.5) of the stomach contents and is needed to activate the protein-digesting enzyme, pepsin. The acidity also kills much of the bacteria you ingest with food and helps to denature proteins, making them more available for enzymatic digestion. Intrinsic factor is a glycoprotein necessary for the absorption of vitamin B12 in the small intestine. Chief cellsLocated primarily in the basal regions of gastric glands are chief cells, which secrete pepsinogen, the inactive proenzyme form of pepsin. HCl is necessary for the conversion of pepsinogen to pepsin. Mucous neck cellsGastric glands in the upper part of the stomach contain mucous neck cells that secrete thin, acidic mucus that is much different from the mucus... Q: The stomach mucosa's epithelial lining consists only of surface mucus cells, which secrete a protective coat of what? Choices: - bile mucus - phosphate mucus - acidic mucus - alkaline mucus A:

Ans:alkaline mucus
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Ques:Answer the following question given this paragraph: Trophic level 4 = tertiary consumers that eat secondary consumers. Q: Trophic level 4 = tertiary consumers that eat what kind of consumers? Choices: - insects - herbivores - primary consumers - secondary consumers A:

Ans:secondary consumers
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Ques:Answer the following question given this paragraph: Chapter 30 1 Figure 30.7 A and B. The cortex, pith, and epidermis are made of parenchyma cells. 3 Figure 30.34 B. 4 C 6 C 8 A 10 B 12 A 14 B 16 C 18 B 20 D 22 C 24 C 26 C 27 Lawn grasses and other monocots have an intercalary meristem, which is a region of meristematic tissue at the base of the leaf blade. This is beneficial to the plant because it can continue to grow even when the tip of the plant is removed by grazing or mowing. 29 Stomata allow gases to enter and exit the plant. Guard cells regulate the opening and closing of stomata. If these cells did not function correctly, a plant could not get the carbon dioxide needed for photosynthesis, nor could it release the oxygen produced by photosynthesis. 31 In woody plants, the cork cambium is the outermost lateral meristem; it produces new cells towards the interior, which enables the plant to increase in girth. The cork cambium also produces cork cells towards the exterior, which protect the plant from physical damage while reducing water loss. 33 Annual rings can also indicate the climate conditions that prevailed during each growing season. 35 A tap root system. Q: Regulated by guard cells, stomata allow what to enter and exit the plant? Choices: - molecules - fluid - nutrients - gases A:

Ans:
gases
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