Answer the following question given this paragraph: Q: Activated macrophages and neutrophils discharge what that signals molecules that enhance an immune response? Choices: - alkaloids - pathogens - nucelotides - cytokines A:
cytokines
Answer the following question given this paragraph: Organisms can use different strategies to increase their reproduction rate. Altricial organisms are helpless at birth, and their parents give them a lot of care. This care is often seen in bird species. ( Figure below ). Altricial birds are usually born blind and without feathers. Compared to precocial organisms, altricial organisms have a longer period of development before they reach maturity. Precocial organisms, such as the geese shown below, can take care of themselves at birth and do not require help from their parents ( Figure below ). In order to reproduce as much as possible, altricial and precocial organisms must use very different strategies. Q: What type of organisms are helpless at birth and require lots of help from their parents? Choices: - Microorganisms - multicellular organisms - precocial organisms - altricial organisms A:
altricial organisms
Q: Answer the following question given this paragraph: Community Dynamics Community dynamics are the changes in community structure and composition over time. Sometimes these changes are induced by environmental disturbances such as volcanoes, earthquakes, storms, fires, and climate change. Communities with a stable structure are said to be at equilibrium. Following a disturbance, the community may or may not return to the equilibrium state. Succession describes the sequential appearance and disappearance of species in a community over time. In primary succession, newly exposed or newly formed land is colonized by living things; in secondary succession, part of an ecosystem is disturbed and remnants of the previous community remain. Primary Succession and Pioneer Species Primary succession occurs when new land is formed or rock is exposed: for example, following the eruption of volcanoes, such as those on the Big Island of Hawaii. As lava flows into the ocean, new land is continually being formed. On the Big Island, approximately 32 acres of land is added each year. First, weathering and other natural forces break down the substrate enough for the establishment of certain hearty plants and lichens with few soil requirements, known as pioneer species (Figure 45.32). These species help to further break down the mineral rich lava into soil where other, less hardy species will grow and eventually replace the pioneer species. In addition, as these early species grow and die, they add to an ever-growing layer of decomposing organic material and contribute to soil formation. Over time the area will reach an equilibrium state, with a set of organisms quite different from the pioneer species. Q: Loss of what eventually threatens other species not impacted directly, because of their interconnectedness; as species disappear from an ecosystem others are threatened by changes in available resources? Choices: - technology - oxygen - climate - biodiversity A:
A: biodiversity
Question: Answer the following question given this paragraph: Hydraulic car lifts also use fluid to transmit pressure and increase force. The lifts are used to raise cars, which are very heavy, so mechanics can work on them from underneath. Controls in airplanes use fluids to transmit pressure and increase force so a flick of a switch can raise or lower heavy landing gear. To see animations of hydraulic systems such as these, go to URLs:. Q: What kind of systems use fluid to transmit pressure and increase force? Choices: - plumbing systems - thermal systems - electromagnetic systems - hydraulic systems A:
Answer: hydraulic systems
*Question*
Answer the following question given this paragraph: Q: What pathway in a plant do water and nutrients travel through from the roots to the leaves? Choices: - bark - flowers - skin - stem A:
**Answer**
stem
(Q).
Answer the following question given this paragraph: The central nervous includes the brain and spinal cord. The brain is the control center of the nervous system. It controls virtually all mental and physical processes. The spinal cord is a long, thin bundle of nervous tissue that passes messages from the body to the brain and from the brain to the body. Q: The brain and spinal cord are part of what system, which serves as a control center? Choices: - primary nervous system - active nervous system - large nervous system - central nervous system A:
(A).
central nervous system