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oviparity : process by which fertilized eggs are laid outside the female’s body and develop there, receiving nourishment from the yolk that is a part of the egg
https://openstax.org/books/biology/pages/43-key-terms
ovoviparity : process by which fertilized eggs are retained within the female; the embryo obtains its nourishment from the egg’s yolk and the young are fully developed when they are hatched
https://openstax.org/books/biology/pages/43-key-terms
ovulation : release of the egg by the most mature follicle
https://openstax.org/books/biology/pages/43-key-terms
parthenogenesis : form of asexual reproduction where an egg develops into a complete individual without being fertilized
https://openstax.org/books/biology/pages/43-key-terms
penis : male reproductive structure for urine elimination and copulation
https://openstax.org/books/biology/pages/43-key-terms
placenta : organ that supports the diffusion of nutrients and waste between the mother’s and fetus’ blood
https://openstax.org/books/biology/pages/43-key-terms
polyspermy : condition in which one egg is fertilized by multiple sperm
https://openstax.org/books/biology/pages/43-key-terms
progesterone : reproductive hormone in women; assists in endometrial re-growth and inhibition of FSH and LH release
https://openstax.org/books/biology/pages/43-key-terms
prostate gland : structure that is a mixture of smooth muscle and glandular material and that contributes to semen
https://openstax.org/books/biology/pages/43-key-terms
scrotum : sac containing testes; exterior to the body
https://openstax.org/books/biology/pages/43-key-terms
semen : fluid mixture of sperm and supporting materials
https://openstax.org/books/biology/pages/43-key-terms
seminal vesicle : secretory accessory gland in males; contributes to semen
https://openstax.org/books/biology/pages/43-key-terms
seminiferous tubule : site of sperm production in testes
https://openstax.org/books/biology/pages/43-key-terms
Sertoli cell : cell in seminiferous tubules that assists developing sperm and makes inhibin
https://openstax.org/books/biology/pages/43-key-terms
sexual reproduction : mixing of genetic material from two individuals to produce genetically unique offspring
https://openstax.org/books/biology/pages/43-key-terms
somite : group of cells separated by small spaces that form from the mesoderm and give rise to connective tissue
https://openstax.org/books/biology/pages/43-key-terms
spermatheca : specialized sac that stores sperm for later use
https://openstax.org/books/biology/pages/43-key-terms
spermatogenesis : process of producing haploid sperm
https://openstax.org/books/biology/pages/43-key-terms
testes : pair of reproductive organs in males
https://openstax.org/books/biology/pages/43-key-terms
testosterone : reproductive hormone in men that assists in sperm production and promoting secondary sexual characteristics
https://openstax.org/books/biology/pages/43-key-terms
trophoblast : outer layer of cells in the blastocyst
https://openstax.org/books/biology/pages/43-key-terms
uterus : environment for developing embryo and fetus
https://openstax.org/books/biology/pages/43-key-terms
vagina : muscular tube for the passage of menstrual flow, copulation, and birth of offspring
https://openstax.org/books/biology/pages/43-key-terms
viviparity : process in which the young develop within the female, receiving nourishment from the mother’s blood through a placenta
https://openstax.org/books/biology/pages/43-key-terms
zona pellucida : protective layer of glycoproteins on the mammalian egg
https://openstax.org/books/biology/pages/43-key-terms
Ecology is the study of the interactions of living things with their environment. Ecologists ask questions across four levels of biological organization—organismal, population, community, and ecosystem. At the organismal level, ecologists study individual organisms and how they interact with their environments. At th...
https://openstax.org/books/biology/pages/44-chapter-summary
Biogeography is the study of the geographic distribution of living things and the abiotic factors that affect their distribution. Endemic species are species that are naturally found only in a specific geographic area. The distribution of living things is influenced by several environmental factors that are, in part, c...
https://openstax.org/books/biology/pages/44-chapter-summary
The Earth has terrestrial biomes and aquatic biomes. Aquatic biomes include both freshwater and marine environments. There are eight major terrestrial biomes: tropical wet forests, savannas, subtropical deserts, chaparral, temperate grasslands, temperate forests, boreal forests, and Arctic tundra. The same biome can oc...
https://openstax.org/books/biology/pages/44-chapter-summary
Aquatic ecosystems include both saltwater and freshwater biomes. The abiotic factors important for the structuring of aquatic ecosystems can be different than those seen in terrestrial systems. Sunlight is a driving force behind the structure of forests and also is an important factor in bodies of water, especially tho...
https://openstax.org/books/biology/pages/44-chapter-summary
The Earth has gone through periodic cycles of increases and decreases in temperature. During the past 2000 years, the Medieval Climate Anomaly was a warmer period, while the Little Ice Age was unusually cool. Both of these irregularities can be explained by natural causes of changes in climate, and, although the temper...
https://openstax.org/books/biology/pages/44-chapter-summary
abiotic : nonliving components of the environment
https://openstax.org/books/biology/pages/44-key-terms
aboveground biomass : total mass of aboveground living plants per area
https://openstax.org/books/biology/pages/44-key-terms
abyssal zone : deepest part of the ocean at depths of 4000 m or greater
https://openstax.org/books/biology/pages/44-key-terms
algal bloom : rapid increase of algae in an aquatic system
https://openstax.org/books/biology/pages/44-key-terms
aphotic zone : part of the ocean where no light penetrates
https://openstax.org/books/biology/pages/44-key-terms
benthic realm : (also, benthic zone) part of the ocean that extends along the ocean bottom from the shoreline to the deepest parts of the ocean floor
https://openstax.org/books/biology/pages/44-key-terms
biogeography : study of the geographic distribution of living things and the abiotic factors that affect their distribution
https://openstax.org/books/biology/pages/44-key-terms
biome : ecological community of plants, animals, and other organisms that is adapted to a characteristic set of environmental conditions
https://openstax.org/books/biology/pages/44-key-terms
biotic : living components of the environment
https://openstax.org/books/biology/pages/44-key-terms
canopy : branches and foliage of trees that form a layer of overhead coverage in a forest
https://openstax.org/books/biology/pages/44-key-terms
channel : width of a river or stream from one bank to the other bank
https://openstax.org/books/biology/pages/44-key-terms
clathrates : frozen chunks of ice and methane found at the bottom of the ocean
https://openstax.org/books/biology/pages/44-key-terms
climate : long-term, predictable atmospheric conditions present in a specific area
https://openstax.org/books/biology/pages/44-key-terms
conspecifics : individuals that are members of the same species
https://openstax.org/books/biology/pages/44-key-terms
coral reef : ocean ridges formed by marine invertebrates living in warm, shallow waters within the photic zone
https://openstax.org/books/biology/pages/44-key-terms
cryptofauna : invertebrates found within the calcium carbonate substrate of coral reefs
https://openstax.org/books/biology/pages/44-key-terms
ecology : study of interaction between living things and their environment
https://openstax.org/books/biology/pages/44-key-terms
ecosystem services : human benefits and services provided by natural ecosystems
https://openstax.org/books/biology/pages/44-key-terms
emergent vegetation : wetland plants that are rooted in the soil but have portions of leaves, stems, and flowers extending above the water’s surface
https://openstax.org/books/biology/pages/44-key-terms
endemic : species found only in a specific geographic area that is usually restricted in size
https://openstax.org/books/biology/pages/44-key-terms
estuary : biomes where a source of fresh water, such as a river, meets the ocean
https://openstax.org/books/biology/pages/44-key-terms
fall and spring turnover : seasonal process that recycles nutrients and oxygen from the bottom of a freshwater ecosystem to the top
https://openstax.org/books/biology/pages/44-key-terms
global climate change : altered global weather patterns, including a worldwide increase in temperature, due largely to rising levels of atmospheric carbon dioxide
https://openstax.org/books/biology/pages/44-key-terms
greenhouse effect : warming of Earth due to carbon dioxide and other greenhouse gases in the atmosphere
https://openstax.org/books/biology/pages/44-key-terms
greenhouse gases : atmospheric gases such as carbon dioxide and methane that absorb and emit radiation, thus trapping heat in Earth’s atmosphere
https://openstax.org/books/biology/pages/44-key-terms
haze-effect cooling : effect of the gases and solids from a volcanic eruption on global climate
https://openstax.org/books/biology/pages/44-key-terms
heterospecifics : individuals that are members of different species
https://openstax.org/books/biology/pages/44-key-terms
intertidal zone : part of the ocean that is closest to land; parts extend above the water at low tide
https://openstax.org/books/biology/pages/44-key-terms
Milankovitch cycles : cyclic changes in the Earth's orbit that may affect climate
https://openstax.org/books/biology/pages/44-key-terms
neritic zone : part of the ocean that extends from low tide to the edge of the continental shelf
https://openstax.org/books/biology/pages/44-key-terms
net primary productivity : measurement of the energy accumulation within an ecosystem, calculated as the total amount of carbon fixed per year minus the amount that is oxidized during cellular respiration
https://openstax.org/books/biology/pages/44-key-terms
ocean upwelling : rising of deep ocean waters that occurs when prevailing winds blow along surface waters near a coastline
https://openstax.org/books/biology/pages/44-key-terms
oceanic zone : part of the ocean that begins offshore where the water measures 200 m deep or deeper
https://openstax.org/books/biology/pages/44-key-terms
pelagic realm : (also, pelagic zone) open ocean waters that are not close to the bottom or near the shore
https://openstax.org/books/biology/pages/44-key-terms
permafrost : perennially frozen portion of the Arctic tundra soil
https://openstax.org/books/biology/pages/44-key-terms
photic zone : portion of the ocean that light can penetrate
https://openstax.org/books/biology/pages/44-key-terms
planktivore : animal species that eats plankton
https://openstax.org/books/biology/pages/44-key-terms
predator : animal species that hunt and are carnivores or “flesh eaters”
https://openstax.org/books/biology/pages/44-key-terms
Sargassum : type of free-floating marine seaweed
https://openstax.org/books/biology/pages/44-key-terms
solar intensity : amount of solar power energy the sun emits in a given amount of time
https://openstax.org/books/biology/pages/44-key-terms
source water : point of origin of a river or stream
https://openstax.org/books/biology/pages/44-key-terms
thermocline : layer of water with a temperature that is significantly different from that of the surrounding layers
https://openstax.org/books/biology/pages/44-key-terms
weather : conditions of the atmosphere during a short period of time
https://openstax.org/books/biology/pages/44-key-terms
Populations are individuals of a species that live in a particular habitat. Ecologists measure characteristics of populations: size, density, dispersion pattern, age structure, and sex ratio. Life tables are useful to calculate life expectancies of individual population members. Survivorship curves show the number of i...
https://openstax.org/books/biology/pages/45-chapter-summary
All species have evolved a pattern of living, called a life history strategy, in which they partition energy for growth, maintenance, and reproduction. These patterns evolve through natural selection; they allow species to adapt to their environment to obtain the resources they need to successfully reproduce. There is ...
https://openstax.org/books/biology/pages/45-chapter-summary
Populations with unlimited resources grow exponentially, with an accelerating growth rate. When resources become limiting, populations follow a logistic growth curve. The population of a species will level off at the carrying capacity of its environment.
https://openstax.org/books/biology/pages/45-chapter-summary
Populations are regulated by a variety of density-dependent and density-independent factors. Species are divided into two categories based on a variety of features of their life history patterns:r-selected species, which have large numbers of offspring, andK-selected species, which have few offspring. Ther- andK-select...
https://openstax.org/books/biology/pages/45-chapter-summary
The world’s human population is growing at an exponential rate. Humans have increased the world’s carrying capacity through migration, agriculture, medical advances, and communication. The age structure of a population allows us to predict population growth. Unchecked human population growth could have dire long-te...
https://openstax.org/books/biology/pages/45-chapter-summary
Communities include all the different species living in a given area. The variety of these species is called species richness. Many organisms have developed defenses against predation and herbivory, including mechanical defenses, warning coloration, and mimicry, as a result of evolution and the interaction with other m...
https://openstax.org/books/biology/pages/45-chapter-summary
Behaviors are responses to stimuli. They can either be instinctual/innate behaviors, which are not influenced by the environment, or learned behaviors, which are influenced by environmental changes. Instinctual behaviors include mating systems and methods of communication. Learned behaviors include imprinting and habit...
https://openstax.org/books/biology/pages/45-chapter-summary
age structure : proportion of population members at specific age ranges
https://openstax.org/books/biology/pages/45-key-terms
aggressive display : visual display by a species member to discourage other members of the same species or different species
https://openstax.org/books/biology/pages/45-key-terms
aposematic coloration : warning coloration used as a defensive mechanism against predation
https://openstax.org/books/biology/pages/45-key-terms
Batesian mimicry : type of mimicry where a non-harmful species takes on the warning colorations of a harmful one
https://openstax.org/books/biology/pages/45-key-terms
behavior : change in an organism’s activities in response to a stimulus
https://openstax.org/books/biology/pages/45-key-terms
behavioral biology : study of the biology and evolution of behavior
https://openstax.org/books/biology/pages/45-key-terms
biotic potential (rmax) : maximal potential growth rate of a species
https://openstax.org/books/biology/pages/45-key-terms
birth rate (B) : number of births within a population at a specific point in time
https://openstax.org/books/biology/pages/45-key-terms
camouflage : avoid detection by blending in with the background.
https://openstax.org/books/biology/pages/45-key-terms
carrying capacity (K) : number of individuals of a species that can be supported by the limited resources of a habitat
https://openstax.org/books/biology/pages/45-key-terms
classical conditioning : association of a specific stimulus and response through conditioning
https://openstax.org/books/biology/pages/45-key-terms
climax community : final stage of succession, where a stable community is formed by a characteristic assortment of plant and animal species
https://openstax.org/books/biology/pages/45-key-terms
cognitive learning : knowledge and skills acquired by the manipulation of information in the mind
https://openstax.org/books/biology/pages/45-key-terms
commensalism : relationship between species wherein one species benefits from the close, prolonged interaction, while the other species neither benefits nor is harmed
https://openstax.org/books/biology/pages/45-key-terms
competitive exclusion principle : no two species within a habitat can coexist when they compete for the same resources at the same place and time
https://openstax.org/books/biology/pages/45-key-terms
conditioned behavior : behavior that becomes associated with a specific stimulus through conditioning
https://openstax.org/books/biology/pages/45-key-terms
courtship display : visual display used to attract a mate
https://openstax.org/books/biology/pages/45-key-terms
death rate (D) : number of deaths within a population at a specific point in time
https://openstax.org/books/biology/pages/45-key-terms
demographic-based population model : modern model of population dynamics incorporating many features of ther- andK-selection theory
https://openstax.org/books/biology/pages/45-key-terms
demography : statistical study of changes in populations over time
https://openstax.org/books/biology/pages/45-key-terms