No species can exist alone in a habitat.  Any species has a minimal requirement of at least one more species, on which it can feed.  Interspecific interactions arise from the interaction of populations of two different species.
(a) What term is given to the interaction, where one species is benefitted and the other is neutral?
(b) Give four examples of the above kind of interaction.
(c) How do you call the interaction where one species is neutral and the other is harmed? Give an example of such an interaction.
(d) What value do you learn from this?

'Struggle for existence and survival of the fittest' is Darwin's theory of Natural selection.  Interspecific competition, a potent force in organic evolution, is generally believed to occur between closely related species for the same resources, that are limiting, but this is not entirely true.
(a) Give an example where totally unrelated species could compete with each other.
(b) Resources need not be limiting for competition to occur.  Justify with an example.
(c) What value is learnt from this?

Ram saw that in his village farmers always used to plough the field before sowing seeds of any crop.He discussed his observation with his grandfather who explained that this practice helps to improve productivity  by providing better aeration, water absorption and availability of nutrients to plants.
Read the above passage and answer the following questions:
(i) What is soil?
(ii) Which factors of soil affect soil fertility?
(iii) What value is displayed by Ram?

In a biology class, teacher was telling the students that the structures/components and their functions in a watch can be compared with various lenels of organisation we find in nature. Radhika was surprised and asked teacher to explain it. Teacher got impressed with Radhika's interest and explained that there is a systematic arrangement of smaller and simpler components into larger one in a hierarchy or pyramid having different levels where each level and itself is formed of components of lower level and itself becomes part of hgher level for achieving a common goal.
(i) What are the four levels of biological organisation found in nature?
(ii) What is the basic unit of ecological organisation
(iii) Define community
(iv) What value are shown by Radhika?

A group of students visited a botanical garden, where they saw fungus growing on roots of higher plants only. They were confused seeing it then, their teacher told them that it is an interspecific interaction in which both species can be benefitted.
(i) Write the name of this particular association
(ii) How both are benefitted from each other?
(iii) State use of this interaction to a farmer
(iv) What values are shown by students