C 4.1 Populations and communities

Syllabus statements

C4.1.1 Populations as interacting groups of organisms of the same species living in an area

C4.1.2 Estimation of population size by random sampling

C4.1.3 Random quadrat sampling to estimate population size for sessile organisms

C4.1.4 Capture–mark–release–recapture and the Lincoln index to estimate population size for motile organisms

C4.1.5 Carrying capacity and competition for limited resources

C4.1.6 Negative feedback control of population size by density-dependent factors

C4.1.7 Population growth curves

C4.1.8 Modelling of the sigmoid population growth curve

C4.1.9 Competition versus cooperation in intraspecific relationships

C4.1.10 A community as all of the interacting organisms in an ecosystem

C4.1.11 Herbivory, predation, interspecific competition, mutualism, parasitism and pathogenicity as categories of interspecific relationship within communities categories of interspecific relationship within communities

C4.1.12 Mutualism as an interspecific relationship that benefits both species

C4.1.13 Resource competition between endemic and invasive species

C4.1.14 Tests for interspecific competition

C4.1.15 Use of the chi-squared test for association between two species

C4.1.16 Predator–prey relationships as an example of density-dependent control of animal populations

C4.1.17 Top-down and bottom-up control of populations in communities

C4.1.18 Allelopathy and secretion of antibiotics