Study the statements and select the correct ones
(a) A lion eating a deer represents predator-prey relationships.
(b) Predator star fish, pisaster, helps in maintaining species diversity of some invertebrates.
(c) Predators ultimately lead to extinction of prey species
(d) Plant chemicals like nicotine and strychnine are produced due to metabolic disorders.

The correct option is C a and b
The sparrow feeding on the grain and the lion feeding on the deer are both considered predators.
The presence of keystone species is crucial for maintaining numbers and diversity of other species, which makes their role exceptional in the ecosystem. Predator star fish, pisaster, helps in maintaining species diversity of some invertebrates.
Plant chemicals like nicotine and strychnine are produced as secondary metabolites in plants. They often play an important role in plant defense against herbivory and other interspecies defenses.