Organism and Population MCQs for NEET — Botany Questions with Answers

The NCERT text defines the components: '(iii) Immigration is the number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration.'

The NCERT explicitly uses Pacific salmon fish as an example of organisms that have evolved to breed only once in their lifetime, which is a life history trait reflecting an efficient reproductive strategy under particular selection pressures.

The NCERT text states: 'Evolution of life history traits in different species is currently an important area of research being conducted by ecologists.'

The text states, 'a sparrow eating any seed is no less a predator.' While animals eating plants are often categorized as herbivores, in a broad ecological context, they are not very different from predators. Therefore, predation is the most accurate description.

The text explicitly states: 'They keep prey populations under control...Predators also help in maintaining species diversity in a community, by reducing the intensity of competition among competing prey species.'

The text mentions, 'When certain exotic species are introduced into a geographical area, they become invasive and start spreading fast because the invaded land does not have its natural predators.' The prickly pear cactus in Australia is given as a specific example of this phenomenon.

The text states, 'If a predator is too efficient and overexploits its prey, then the prey might become extinct and following it, the predator will also become extinct for lack of food. This is the reason why predators in nature are prudent.'

The text mentions, 'Thorns (Acacia, Cactus) are the most common morphological means of defence.' The other options are chemical defenses.

The text explains, 'The Monarch butterfly is highly distasteful to its predator (bird) because of a special chemical present in its body. Interestingly, the butterfly acquires this chemical during its caterpillar stage by feeding on a poisonous weed.'

The context states, 'Many plants produce and store chemicals that make the herbivore sick when they are eaten... The plant produces highly poisonous cardiac glycosides and that is why you never see any cattle or goats browsing on this plant.' This clearly indicates a defense against herbivory.