Answer the following question given this paragraph: Arctic Tundra The Arctic tundra lies north of the subarctic boreal forests and is located throughout the Arctic regions of the Northern Hemisphere (Figure 20.18). Tundra also exists at elevations above the tree line on mountains. The average winter temperature is 34C (29.2F) and the average summer temperature is 3C12C (37F 52F). Plants in the Arctic tundra have a short growing season of approximately 5060 days. However, during this time, there are almost 24 hours of daylight and plant growth is rapid. The annual precipitation of the Arctic tundra is low (1525 cm or 610 in) with little annual variation in precipitation. And, as in the boreal forests, there is little evaporation because of the cold temperatures. Plants in the Arctic tundra are generally low to the ground and include low shrubs, grasses, lichens, and small flowering plants (Figure 20.26). There is little species diversity, low net primary productivity, and low aboveground biomass. The soils of the Arctic tundra may remain in a perennially frozen state referred to as permafrost. The permafrost makes it impossible for roots to penetrate far into the soil and slows the decay of organic matter, which inhibits the release of nutrients from organic matter. The melting of the permafrost in the brief summer provides water for a burst of productivity while temperatures and long days permit it. During the growing season, the ground of the Arctic tundra can be completely covered with plants or lichens. Q: Why is there very little evaporation in the boreal forests? Choices: - too hot - too humid - high elevation - temperature is too cold A:
temperature is too cold
Answer the following question given this paragraph: 13 Photosynthesis 6 CO2 + 6 H2 O C6 H12 O6 + 6 O2 One of most important reactions in history of life: source of atmospheric O2 ultimately led to aerobic respiration and eukaryotes Responsible for bulk of glucose production Early experiments showed that mass of plant must be derived from substances in the air, not the soil Experiments with isotopes showed that liberated oxygen comes from water Experiments also showed that light is essential but that some reactions (e. , reduction of CO2 ) continue in the dark Plants do two big, important things during photosynthesis: gain energy (absorb light) and build sugar (glucose). Photosynthesis can be divided into two series of chemical reactions: the light (lightdependent) reactions and the dark (light-independent) reactions. In light reactions, light is absorbed; in dark reactions, sugar is built. Occurs when plants, algae, and autotrophic bacteria absorb light energy and build glucose. Q: What is the process by which plants gain energy and produce sugar? Choices: - glycolysis - respiration - chemosynthesis - photosynthesis A:
photosynthesis
Q: Answer the following question given this paragraph: Molecules within a liquid are pulled equally in all directions by intermolecular forces. However, molecules at the surface are pulled downwards and sideways by other liquid molecules, but not upwards away from the surface. The overall effect is that the surface molecules are pulled into the liquid, creating a surface that is tightened like a film. This phenomenon is referred to as surface tension . Liquids that have strong intermolecular forces, like the hydrogen bonding in water, exhibit the greatest surface tension. Table below shows surface tension values for various common liquids. Q: Surface tension is a property of matter that is in what state? Choices: - mixture - water - Base - liquid A:
A: liquid
Question: Answer the following question given this paragraph: Biochemical reactions are chemical reactions that take place inside living things. Two of the most important biochemical reactions are photosynthesis and cellular respiration. Q: Where do biochemical reactions occer? Choices: - outside organisms - inside labs - in the environment - inside organisms A:
Answer: inside organisms
*Question*
Answer the following question given this paragraph: Mucosal Immune System The innate and adaptive immune responses compose the systemic immune system (affecting the whole body), which is distinct from the mucosal immune system. Mucosa associated lymphoid tissue (MALT) is a crucial component of a functional immune system because mucosal surfaces, such as the nasal passages, are the first tissues onto which inhaled or ingested pathogens are deposited. The mucosal tissue includes the mouth, pharynx, and esophagus, and the gastrointestinal, respiratory, and urogenital tracts. Mucosal immunity is formed by MALT, which functions independently of the systemic immune system, and which has its own innate and adaptive components. MALT is a collection of lymphatic tissue that combines with epithelial tissue lining the mucosa throughout the body. This tissue functions as the immune barrier and response in areas of the body with direct contact to the external environment. The systemic and mucosal immune systems use many of the same cell types. Foreign particles that make their way to MALT are taken up by absorptive epithelial cells and delivered to APCs located directly below the mucosal tissue. APCs of the mucosal immune system are primarily dendritic cells, with B cells and macrophages. Q: What is a collection of lymphatic tissue that combines with epithelial tissue lining the mucosa throughout the body? Choices: - unassociated lymphoid tissue - spheroids associated lymphoid tissue ( malt ) - cottony associated lymphoid tissue ( malt ) - mucosa associated lymphoid tissue (malt) A:
**Answer**
mucosa associated lymphoid tissue (malt)
Q: Answer the following question given this paragraph: would not be surprised if the surviving populations experienced serious bottlenecks. The subsequent diversification of the surviving organisms, such as the Dinosauria (which includes the extinct dinosaurs and modern birds) and the Cynodontia, which includes the ancestors of modern mammals, including us, could be due in part to these bottleneck-associated effects, for example, through the removal of competing species or predators. An astreroid impact, known as the Cretaceous-Tertiary event, occurred ~65 million years ago; it contributed to the extinction of the dinosaurs and led to the diversification of mammals (which had first appeared in the fossil record ~160 million years ago). While surviving an asteroid impact (or other dramatic changes in climate) may be random, in other cases who survives a bottleneck is not. Consider the effects of a severe drought or highly virulent bacterial or viral infection; the organisms that survive may have specific phenotypes (and associated genotypes) that significantly influence their chance of survival. In such a case, the effect of the bottleneck event would produce non-random changes in the distribution of genotypes (and alleles) in the post-bottleneck population these selective effects could continue to influence the population in various ways. For example, a trait associated with pathogen resistance may also have negative phenotypic effects. After the pathogen-driven bottleneck, mutations that mitigate the resistance trait's negative effects (and may have their own effects) can be selected. The end result is that traits that would not be selected in the absence of the pathogen, are selected. In addition, the very occurrence of a rapid and extreme reduction in population size has its own effects. For example, it would be expected to increase the effects of genetic drift (see below) and could make finding a mate more difficult. We can identify extreme population reduction events, such as founder effects and bottlenecks, by looking at the variation in genotypes (that... Q: The rate of the accumulation of neutral what serves as a type of population-based biological clock? Choices: - prokaryotic - enzymes - eukaryotes - polymorphisms A:
A: polymorphisms