Class name Subject Book title Chapter number Content Created at
Class XII Biology Biology 11 We are mostly obliged to estimate population sizes indirectly,withoutactuallycountingthemorseeingthem.Thetigercensus in our national parks and tige...
Class XII Biology Biology 11 other two factors assuming importance only under special conditions. For instance, if a new habitat is just being colonised, immigration may contri...
Class XII Biology Biology 11 For calculating it, you need to know the birth rates and death rates. The above equation describes the exponential or geometric growth pattern of a...
Class XII Biology Biology 11 first square and proceeded to fill the other squares following minister’s suggested procedure, but by the time he covered half the chess board, the...
Class XII Biology Biology 4 behaviour of chromosomes was parallel to the behaviour of genes and used chromosome movement (Figure 4.8) to explain Mendel’s laws (Table 4.3). Rec...
Class XII Biology Biology 11 more realistic one. Gather from Government Census data the population figures for India for the last 100 years, plot them and check which growth pa...
Class XII Biology Biology 11 species. They could be beneficial, detrimental or neutral (neither harm nor benefit) to one of the species or both. Assigning a ‘+’ sign for benefi...
Class XII Biology Biology 11 invasive and start spreading fast because the invaded land does not have its natural predators. The prickly pear cactus introduced into Australia i...
Class XII Biology Biology 11 the most common morphological means of defence. Many plants produce and store chemicals that make the herbivore sick when they are eaten, inhibit f...
Class XII Biology Biology 11 conclusive. Strong and persuasive circumstantial evidence does exist however in some cases. The Abingdon tortoise in Galapagos Islands became extin...
Class XII Biology Biology 11 parasites have evolved to be host-specific (they can parasitise only a single species of host) in such a way that both host and the parasite tend t...
Class XII Biology Biology 11 cells, etc.). The life cycles of endoparasites are more complex because of their extreme specialisation. Their morphological and anatomical feature...
Class XII Biology Biology 11 is pollinated by wasp; (b) Wasp laying eggs in a fig fruit (v) Mutualism: Thisinteractionconfersbenefitsonboththeinteracting species. Lichens repre...
Class XII Biology Biology 11 deceit’ to get pollination done by a species of bee. One petal of its flower bears an uncanny resemblance to the female of the bee in size, colour ...
Class XII Biology Biology 11 through births and immigration and decline through deaths and emigration. When resources are unlimited, the growth is usually exponential but when ...
Class XII Biology Biology 11 terms and give one example for each: (a) Commensalism (b) Parasitism (c) Camouflage (d) Mutualism (e) Interspecific competition 8. With the help of...
Class XII Biology Biology 12 CHAPTER 12 ECOSYSTEM 12.1 Ecosystem–Structure andFunction An ecosystem can be visualised as a functional unit of 12.2. Productivity nature,whereliv...
Class XII Biology Biology 12 occupying different levels is called stratification. For example, trees occupy top verticalstrataorlayerofaforest,shrubsthesecondandherbsandgrasses...
Class XII Biology Biology 12 (kcal m ). The rate of biomass production is called productivity. –2 –1 – –1 It is expressed in terms of gm yr or (kcal m ) yr to compare the produ...
Class XII Biology Biology 12 raw material for decomposition. The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification and miner...
Class XII Biology Biology 12 energy captured by plants flows through different organisms of an ecosystem.Allorganismsaredependentfortheirfoodonproducers,either directly or indi...
Class XII Biology Biology 12 A simple grazing food chain (GFC) is depicted below: Grass Goat Man (Producer) (Primary Consumer) (Secondary consumer) Reprint 2026-27 BIOLOGY The ...
Class XII Biology Biology 12 when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step. Each bar in the energ...
Class XII Biology Biology 12 involves three processes, namely fragmentation of detritus, leaching and catabolism. Energy flow is unidirectional. First, plants capture solar ene...
Class XII Biology Biology 12 of an ecosystem. 8. Define ecological pyramids and describe with examples, pyramids of number and biomass. 9. What is primary productivity? Give br...