Question : Which of the following statements is not correct?
(a) A common functional group is present in different members of a homologous series.
(b) Two consecutive members of a homologous series differ by a –CH3 group.
(c) The members of a homologous series can be represented by one general formula.
(d) Different members of a homologous series have similar chemical properties.
Answer : B
Match the Family given in List-I to their general formula given in List-II and choose the correct option.
(Family) (General formula)
(P) Alkyne 1. CnH2n + 1X
(Q) Alcohol 2. CnH2n – 2
(R) Alkyl halide 3. CnH2n
(S) Alkene 4. CnH2n + 2O
(a) P - 1, Q - 2, R - 3, S - 4
(b) P - 2, Q - 4, R - 1, S - 3
(c) P - 4, Q - 2, R - 1, S - 3
(d) P - 2, Q - 1, R - 3, S - 4
Answer : B
Question : Why should biodegradable and non-biodegradable wastes to be discarded in two separate dustbins?
Why are green plants called ‘producers’?
Answer : Biodegradable wastes are decomposed naturally by the action of microbes into their simple constituents and non-biodegradable wastes cannot be disposed off naturally since they cannot be decomposed by microbes. Such wastes are either recycled, incinerated or put in landfills, etc. As the disposal methods of the two types of wastes are different, it is advisable to discard the two types of waste in two separate dustbins.
Green plants are called producers because they prepare their own food in the presence of sunlight and chlorophyll by the process of photosynthesis.
Question : Why is the progeny of pea plant is always tall when a tall pea plant is crossed with a short pea plant?
Answer : When a tall pea plant is crossed with a short pea plant, the resultant progeny is always tall because tallness is a dominant trait while shortness is a recessive trait. Hence, dominant trait expresses itself in the progeny
Question : Write any four examples of abiotic components of an ecosystem.
Answer : The abiotic components of ecosystem are: temperature, soil, rainfall and minerals.
Question : Why is vegetative propagation needed for growing some plants?
Answer : Vegetative propagation is needed for growing those plants which usually do not produce seeds or produce non-viable seeds.