click below
click below
Normal Size Small Size show me how
9th chap 8.1 ENV
9TH CHAP 8 8.1 AENVIRONMENT OUTLINE
Question | Answer |
---|---|
POPULATION | A _______________ is a group of organisms of the same species that live in a specific geographical area and interbreed. |
BREED | A population is a reproductive group because organisms usually________with members of their own population. |
SIZE | The word population refers to the group in general and also to the ______ of the population, or the number of individuals it contains. |
DENSITY | _________________ is the number of individuals of the same species in that live in a given unit of area. |
DISPERSION | ___________is the pattern of distribution of organisms in a population. A population’s dispersion may be even, clumped, or random. |
PREDICT | Size, density, dispersion, and other properties can be used to describe populations and to __________changes within them. |
BIRTH DEATH | A population gains individuals with each new offspring or _____ and loses them with each ______. |
CHANGE | The resulting population _______ over time can be represented by the equation below. |
GROWTH RATE | ______ _______ is an expression of the increase in the size of an organism or population over a given period of time. It is the birth rate minus the death rate. |
EQUAL | For the growth rate to be zero, the average number of births must ______ the average number of deaths. |
TWO | A population would remain the same size if each pair of adults produced exactly ____ offspring, and each of those offspring survived to reproduce. |
NEGATIVE | If the adults in a population are not replaced by new births, the growth rate will be ______ and the population will shrink |
FACTORS | Populations usually stay about the same size from year to year because various _______ kill many individuals before they can reproduce. |
CARRYING CAPACITY | ___________ _________ is the largest population that an environment can support at any given time. |
BEYOND | A population may increase_____________ this number but it cannot stay at this increased size. |
CRASH | Because ecosystems change, carrying capacity is difficult to predict or calculate exactly. However it may be estimated by looking at average population sizes or by observing a population___________ after a certain size has been exceeded. |
SAME RATE | A species reaches its carrying capacity when it consumes a particular natural resource at the ______ ________ at which the ecosystem produces the resource. |
LIMITING RESOURCE | That natural resource is then called a __________ ______________. |
SUPPLY | The ______________ of the most severely limited resources determines the carrying capacity of an environment for a particular species at a particular time.Competition Within a Population |
COMPETE | The members of a population use the same resources in the same ways, so they will eventually _______ with one another as the population approaches its carrying capacity. |
TERRITORY | instead of competing for a limiting resource, members of a species may compete indirectly for social dominance or for a ____________. |
COMPETITION | _______________within a population is part of the pressure of natural selection. |
TERRITORY | A_______________is an area defended by one or more individuals against other individuals. |
VALUE | The territory is of________not only for the space but for the shelter, food, or breeding sites it contains. |
ENERGY | Many organisms expend a large amount of time and ______ competing with members of the same species for mates, food, or homes for their families. |
DENSELY | Population size can be limited in ways that may or may not depend on the ______________________of the population. |
DEATH | Causes of _________in a population may be density dependent or density independent. |
INDEPENDENT | When a cause of death in a population is density ____________, deaths occur more quickly in a crowded population than in a sparse population. |
DENSILY | This type of regulation happens when individuals of a population are __________ packed together. |
HIGHER | Limited resources, predation and disease result in ________________ rates of death in dense populations than in sparse populations. |
INDEPENDENT | When a cause of death is density __________, a certain proportion of a population may die regardless of the population’s density. |
ALL | This type of regulation affects _____populations in a general or uniform way. |
WEATHER | Severe ________and natural disasters are often density independent causes of death |
EVOLVES | In the long run, the factors also determine how the population __________. |
BIOTIC | A species’ _____________potential is the fastest rate at which its populations can grow. This rate is limited by reproductive potential. |
REPRODUCTIVE POTENTIAL | A species’ biotic potential is the fastest rate at which its populations can grow. This rate is limited by ______________- _____________. |
HIGHER | Some species have much __________ reproductive potentials than others. |
MORE | Reproductive potential increases when individuals produce ______ offspring at a time, reproduce often, and reproduce earlier in life. |
EARLIER | Reproducing _____in life has the greatest effect on reproductive potential. |
GENERATION | Reproducing early shortens the _________ time, or the average time it takes a member of the population to reach the age when it reproduces. |
GROW QUICKLY | Small organisms, such as bacteria and insects, have short generation times and can reproduce when they are only a few hours or a few days old. As a result, their populations can ____________ _________. |
EXPONENTIAL GROWTH | __________ _________ is logarithmic growth or growth in which numbers increase by a certain factor in each successive time period. |
ONLY | Exponential growth occurs in nature _______ when populations have plenty of food and space, and have no competition or predators. |
LARGE | In exponential growth, a __________number of individuals is added to the population in each succeeding time period. |
CANNOT | Because natural conditions are neither ideal nor constant, populations ________ grow forever. |
USED UP | Eventually, resources are ________ __ or the environment changes, and deaths increase or births decrease. |