Biology · Class 12 · Chapter 11
Organisms and Populations
13 lessons99 min3 simulations10 practice questions
This chapter looks at ecology at the level of the population. It covers what a population has that an individual lacks (birth and death rates, sex ratio, age pyramids), how density is measured, how the four processes change it, exponential and logistic growth with r and K, life history strategies, and the six kinds of interaction between species: predation, competition, parasitism, commensalism, amensalism and mutualism.
Also called: population ecology · population interactions · population growth
Lessons
13 lessons · 99 min
01Ecology and populationsNCERT §11.1, §11.1.16 min02Population attributesNCERT §11.1.17 min03Population densityNCERT §11.1.16 min04Four processes of population growthNCERT §11.1.26 min05Exponential growthNCERT §11.1.2 (i)6 min06Logistic growth and life historyNCERT §11.1.2 (ii), §11.1.310 min1 sim07Population interactionsNCERT §11.1.49 min1 sim08PredationNCERT §11.1.4 (i)7 min09CompetitionNCERT §11.1.4 (ii)9 min1 sim10ParasitismNCERT §11.1.4 (iii)7 min11CommensalismNCERT §11.1.4 (iv)6 min12MutualismNCERT §11.1.4 (v)7 min13Chapter reviewMust-know facts, traps and formulas13 min
Simulations
3 in this chapter