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net primary productivity : the energy that remains in the producers after accounting for the organisms’ respiration and heat loss
https://openstax.org/books/concepts-biology/pages/20-key-terms
non-renewable resource : a resource, such as a fossil fuel, that is either regenerated very slowly or not at all
https://openstax.org/books/concepts-biology/pages/20-key-terms
oceanic zone : the part of the ocean that begins offshore where the water measures 200 m deep or deeper
https://openstax.org/books/concepts-biology/pages/20-key-terms
pelagic realm : (also, pelagic zone) the open ocean waters that are not close to the bottom or near the shore
https://openstax.org/books/concepts-biology/pages/20-key-terms
permafrost : a perennially frozen portion of the Arctic tundra soil
https://openstax.org/books/concepts-biology/pages/20-key-terms
photic zone : the upper layer of ocean water in which photosynthesis is able to take place
https://openstax.org/books/concepts-biology/pages/20-key-terms
photoautotroph : an organism that uses sunlight as an energy source to synthesize its own food molecules
https://openstax.org/books/concepts-biology/pages/20-key-terms
planktivore : an animal that eats plankton
https://openstax.org/books/concepts-biology/pages/20-key-terms
primary consumer : the trophic level that obtains its energy from the producers of an ecosystem
https://openstax.org/books/concepts-biology/pages/20-key-terms
producer : the trophic level that obtains its energy from sunlight, inorganic chemicals, or dead or decaying organic material
https://openstax.org/books/concepts-biology/pages/20-key-terms
resilience (ecological) : the speed at which an ecosystem recovers equilibrium after being disturbed
https://openstax.org/books/concepts-biology/pages/20-key-terms
resistance (ecological) : the ability of an ecosystem to remain at equilibrium in spite of disturbances
https://openstax.org/books/concepts-biology/pages/20-key-terms
savanna : a biome located in the tropics with an extended dry season and characterized by a grassland with sparsely distributed trees
https://openstax.org/books/concepts-biology/pages/20-key-terms
secondary consumer : a trophic level in an ecosystem, usually a carnivore that eats a primary consumer
https://openstax.org/books/concepts-biology/pages/20-key-terms
source water : the point of origin of a river or stream
https://openstax.org/books/concepts-biology/pages/20-key-terms
subduction : the movement of one tectonic plate beneath another
https://openstax.org/books/concepts-biology/pages/20-key-terms
subtropical desert : a biome found in the subtropics with hot daily temperatures, very low and unpredictable precipitation, and characterized by a limited dry-adapted vegetation
https://openstax.org/books/concepts-biology/pages/20-key-terms
temperate forest : a biome found in temperate regions with moderate rainfall and dominated structurally by deciduous trees
https://openstax.org/books/concepts-biology/pages/20-key-terms
temperate grassland : a biome dominated by grasses and herbaceous plants due to low precipitation, periodic fires, and grazing
https://openstax.org/books/concepts-biology/pages/20-key-terms
tertiary consumer : a trophic level in an ecosystem, usually carnivores that eat other carnivores
https://openstax.org/books/concepts-biology/pages/20-key-terms
trophic level : the position of a species or group of species in a food chain or a food web
https://openstax.org/books/concepts-biology/pages/20-key-terms
tropical rainforest : a biome found near the equator characterized by stable temperatures with abundant and seasonal rainfall in which trees form the structurally important vegetation
https://openstax.org/books/concepts-biology/pages/20-key-terms
wetland : environment in which the soil is either permanently or periodically saturated with water
https://openstax.org/books/concepts-biology/pages/20-key-terms
Biodiversity exists at multiple levels of organization, and is measured in different ways depending on the goals of those taking the measurements. These include numbers of species, genetic diversity, chemical diversity, and ecosystem diversity. The number of described species is estimated to be 1.5 million with about 1...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
Humans use many compounds that were first discovered or derived from living organisms as medicines: secondary plant compounds, animal toxins, and antibiotics produced by bacteria and fungi. More medicines are expected to be discovered in nature. Loss of biodiversity will impact the number of pharmaceuticals available t...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
Crop diversity is a requirement for food security, and it is being lost. The loss of wild relatives to crops also threatens breeders’ abilities to create new varieties. Ecosystems provide ecosystem services that support human agriculture: pollination, nutrient cycling, pest control, and soil development and maintenan...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
The core threats to biodiversity are human population growth and unsustainable resource use. To date, the most significant causes of extinction are habitat loss, introduction of exotic species, and overharvesting. Climate change is predicted to be a significant cause of extinction in the coming century. Habitat loss oc...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
Five mass extinctions with losses of more than 50 percent of extant species are observable in the fossil record. Recent extinctions are recorded in written history and are the basis for one method of estimating contemporary extinction rates. The other method uses measures of habitat loss and species-area relationships....
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
There is a legislative framework for biodiversity protection. International treaties such as CITES regulate the transportation of endangered species across international borders. Legislation within individual countries protecting species and agreements on global warming have had limited success; there is at present no ...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
Conservation preserves are a major tool in biodiversity protection. Presently, 11 percent of Earth’s land surface is protected in some way. The science of island biogeography has informed the optimal design of preserves; however, preserves have limitations imposed by political and economic forces. In addition, climat...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
Habitat restoration has the potential to restore ecosystems to previous biodiversity levels before species become extinct. Examples of restoration include reintroduction of keystone species and removal of dams on rivers. Zoos have attempted to take a more active role in conservation and can have a limited role in capti...
https://openstax.org/books/concepts-biology/pages/21-chapter-summary
biodiversity : the variety of a biological system, typically conceived as the number of species, but also applying to genes, biochemistry, and ecosystems
https://openstax.org/books/concepts-biology/pages/21-key-terms
biodiversity hotspot : a concept originated by Norman Myers to describe a geographical region with a large number of endemic species and a large percentage of degraded habitat
https://openstax.org/books/concepts-biology/pages/21-key-terms
bush meat : a wild-caught animal used as food (typically mammals, birds, and reptiles); usually referring to hunting in the tropics of sub-Saharan Africa, Asia, and the Americas
https://openstax.org/books/concepts-biology/pages/21-key-terms
chemical diversity : the variety of metabolic compounds in an ecosystem
https://openstax.org/books/concepts-biology/pages/21-key-terms
chytridiomycosis : a disease of amphibians caused by the fungusBatrachochytrium dendrobatidis;thought to be a major cause of the global amphibian decline
https://openstax.org/books/concepts-biology/pages/21-key-terms
ecosystem diversity : the variety of ecosystems
https://openstax.org/books/concepts-biology/pages/21-key-terms
endemic species : a species native to one place
https://openstax.org/books/concepts-biology/pages/21-key-terms
exotic species : (also, invasive species) a species that has been introduced to an ecosystem in which it did not evolve
https://openstax.org/books/concepts-biology/pages/21-key-terms
extinction : the disappearance of a species from Earth; local extinction is the disappearance of a species from a region
https://openstax.org/books/concepts-biology/pages/21-key-terms
extinction rate : the number of species becoming extinct over time, sometimes defined as extinctions per million species–years to make numbers manageable (E/MSY)
https://openstax.org/books/concepts-biology/pages/21-key-terms
genetic diversity : the variety of genes and alleles in a species or other taxonomic group or ecosystem; the term can refer to allelic diversity or genome-wide diversity
https://openstax.org/books/concepts-biology/pages/21-key-terms
habitat heterogeneity : the number of ecological niches
https://openstax.org/books/concepts-biology/pages/21-key-terms
secondary plant compound : a compound produced as a byproduct of plant metabolic processes that is typically toxic, but is sequestered by the plant to defend against herbivores
https://openstax.org/books/concepts-biology/pages/21-key-terms
species-area relationship : the relationship between area surveyed and number of species encountered; typically measured by incrementally increasing the area of a survey and determining the cumulative numbers of species
https://openstax.org/books/concepts-biology/pages/21-key-terms
tragedy of the commons : an economic principle that resources held in common will inevitably be over-exploited
https://openstax.org/books/concepts-biology/pages/21-key-terms
white-nose syndrome : a disease of cave-hibernating bats in the eastern United States and Canada associated with the fungusGeomyces destructans
https://openstax.org/books/concepts-biology/pages/21-key-terms
Human anatomy is the scientific study of the body’s structures. In the past, anatomy has primarily been studied via observing injuries, and later by the dissection of anatomical structures of cadavers, but in the past century, computer-assisted imaging techniques have allowed clinicians to look inside the liv...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Life processes of the human body are maintained at several levels of structural organization. These include the chemical, cellular, tissue, organ, organ system, and the organism level. Higher levels of organization are built from lower levels. Therefore, molecules combine to form cells, cells combine to form tissues, t...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Most processes that occur in the human body are not consciously controlled. They occur continuously to build, maintain, and sustain life. These processes include: organization, in terms of the maintenance of essential body boundaries; metabolism, including energy transfer via anabolic and catabolic reactions; responsiv...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Humans cannot survive for more than a few minutes without oxygen, for more than several days without water, and for more than several weeks without carbohydrates, lipids, proteins, vitamins, and minerals. Although the body can respond to high temperatures by sweating and to low temperatures by shivering and increased f...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Homeostasis is the activity of cells throughout the body to maintain the physiological state within a narrow range that is compatible with life. Homeostasis is regulated by negative feedback loops and, much less frequently, by positive feedback loops. Both have the same components of a stimulus, sensor, control center,...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Ancient Greek and Latin words are used to build anatomical terms. A standard reference position for mapping the body’s structures is the normal anatomical position. Regions of the body are identified using terms such as “occipital” that are more precise than common words and phrases such as “the back of the hea...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
Detailed anatomical drawings of the human body first became available in the fifteenth and sixteenth centuries; however, it was not until the end of the nineteenth century, and the discovery of X-rays, that anatomists and physicians discovered non-surgical methods to look inside a living body. Since then, many other te...
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-chapter-review
abdominopelvic cavity : division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
anabolism : assembly of more complex molecules from simpler molecules
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
anatomical position : standard reference position used for describing locations and directions on the human body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
anatomy : science that studies the form and composition of the body’s structures
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
anterior : describes the front or direction toward the front of the body; also referred to as ventral
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
anterior cavity : larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
catabolism : breaking down of more complex molecules into simpler molecules
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
caudal : describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
cell : smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
computed tomography (CT) : medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
control center : compares values to their normal range; deviations cause the activation of an effector
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
cranial : describes a position above or higher than another part of the body proper; also referred to as superior
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
cranial cavity : division of the posterior (dorsal) cavity that houses the brain
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
deep : describes a position farther from the surface of the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
development : changes an organism goes through during its life
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
differentiation : process by which unspecialized cells become specialized in structure and function
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
distal : describes a position farther from the point of attachment or the trunk of the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
dorsal : describes the back or direction toward the back of the body; also referred to as posterior
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
dorsal cavity : posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
effector : organ that can cause a change in a value
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
frontal plane : two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
gross anatomy : study of the larger structures of the body, typically with the unaided eye; also referred to macroscopic anatomy
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
growth : process of increasing in size
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
homeostasis : steady state of body systems that living organisms maintain
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
inferior : describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
lateral : describes the side or direction toward the side of the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
magnetic resonance imaging (MRI) : medical imaging technique in which a device generates a magnetic field to obtain detailed sectional images of the internal structures of the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
medial : describes the middle or direction toward the middle of the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
metabolism : sum of all of the body’s chemical reactions
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
microscopic anatomy : study of very small structures of the body using magnification
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
negative feedback : homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
normal range : range of values around the set point that do not cause a reaction by the control center
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
nutrient : chemical obtained from foods and beverages that is critical to human survival
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
organ : functionally distinct structure composed of two or more types of tissues
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
organ system : group of organs that work together to carry out a particular function
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
organism : living being that has a cellular structure and that can independently perform all physiologic functions necessary for life
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
pericardium : sac that encloses the heart
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
peritoneum : serous membrane that lines the abdominopelvic cavity and covers the organs found there
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
physiology : science that studies the chemistry, biochemistry, and physics of the body’s functions
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
plane : imaginary two-dimensional surface that passes through the body
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
pleura : serous membrane that lines the pleural cavity and covers the lungs
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
positive feedback : mechanism that intensifies a change in the body’s physiological condition in response to a stimulus
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
positron emission tomography (PET) : medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
posterior : describes the back or direction toward the back of the body; also referred to as dorsal
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
posterior cavity : posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms
pressure : force exerted by a substance in contact with another substance
https://openstax.org/books/anatomy-and-physiology-2e/pages/1-key-terms