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#	Question	Answer
1	What is the essence of biological understanding according to ecology?	Understanding how organisms interact with other organisms and physical habitats as organised wholes.
2	According to the example in the text, why does a bird sing during the breeding season?	To communicate with its mate.
3	At which level does natural selection operate to evolve desired traits?	At the population level.
4	If 4 fruitflies die in a population of 40 in one week, what is the death rate?	0.1 individuals per fruitfly per week.
5	Ecological processes are evaluated in terms of changes in what factor?	Population size.
6	Which measures may be more meaningful than numbers for some populations?	Per cent cover or biomass.
7	Is population size a static parameter?	No, it changes with time.
8	Which two processes decrease population density?	Mortality and emigration.
9	Write the equation for population density at time t + 1.	Nt+1 = Nt + [(B + I) – (D + E)]
10	Which two major types of population growth are described in the text?	Exponential growth and logistic growth.
11	Write the equation for exponential population growth.	dN/dt = rN
12	What type of curve is produced by exponential growth?	J-shaped curve.
13	What can happen to species growing exponentially under unlimited resources?	They can reach enormous population densities in a short time.
14	What is carrying capacity (K)?	The maximum possible number of individuals that a habitat can support.
15	What is another name for logistic growth?	Verhulst-Pearl Logistic Growth.
16	Give examples of organisms that breed only once in their lifetime.	Pacific salmon fish and bamboo.
17	Can a natural habitat be inhabited by only a single species?	No, such a situation is inconceivable.
18	Which interaction benefits both species?	Mutualism.
19	What is amensalism?	One species is harmed while the other remains unaffected.
20	What can happen if predators are absent from an ecosystem?	Prey populations may grow excessively and cause ecosystem instability.
21	What interaction symbols are used for mutualism?	+ +
22	What interaction symbols are used for amensalism?	– 0
23	Why is the Monarch butterfly avoided by predators?	It is highly distasteful due to a special chemical present in its body.
24	What are common morphological defenses in plants against herbivores?	Thorns in Acacia and Cactus.
25	According to Darwin, what is a potent force in organic evolution?	Interspecific competition.
26	Which tortoise became extinct after goats were introduced in the Galapagos Islands?	Abingdon tortoise.
27	How did the warbler species avoid competition?	Through behavioural differences in foraging activities.
28	Which intermediate hosts are involved in the life cycle of the human liver fluke?	A snail and a fish.
29	Why is Cuscuta considered a parasitic plant?	It derives nutrition from the host plant it parasitises.
30	Why are endoparasite life cycles more complex?	Due to their extreme specialisation.
31	Define commensalism.	An interaction where one species benefits while the other is neither harmed nor benefited.
32	What is mutualism?	An interaction in which both species benefit.
33	What do plants require animals for in mutualistic relationships?	Pollination of flowers and dispersal of seeds.
34	How many wasp species generally pollinate a given fig species?	Only one specific partner wasp species.
35	Why are orchids considered evolutionarily fascinating?	Because they show diverse floral patterns adapted to attract specific pollinators.
36	How is pollen transferred in Ophrys orchids?	The bee gets dusted with pollen during pseudocopulation and transfers it to another flower.
37	Name population attributes absent in individuals.	Birth rates, death rates, sex ratio and age distribution.
38	What limits population growth ultimately?	Carrying capacity of the environment.
39	What attributes do populations possess that individuals do not?	Birth rates, death rates, sex ratio and age distribution.
40	Define population.	A group of individuals of a species sharing or competing for similar resources in a defined geographical area.
41	Define mutualism.	An interaction in which both interacting species benefit.
42	Name any three important characteristics of a population.	Birth rate, death rate and sex ratio.