Botany MCQs for NEET — Practice Questions with Answers

The birth rate is calculated as the number of children born per 1000 individuals in a population per year. Given the population of 5000 and 1111 children born, the birth rate can be calculated as: \[\text{Birth Rate} = \frac{1111}{5000} \times 1000 = 222.2 \text{ births per 1000 individuals per year (or 0.2222)}\].

In a lichen, the mycobiont (fungal component) provides minerals and water to the phycobiont (algal component), while the phycobiont performs photosynthesis to produce organic nutrients (like carbohydrates) which are shared with the mycobiont. Therefore, X is minerals and Y is organic nutrients.

Lichens, a symbiotic association of algae and fungi, are often the pioneer species in primary succession on bare rock (xerosere). They are capable of withstanding harsh conditions and contribute to soil formation by breaking down the rock surface.

Interspecific competition occurs between different species that compete for the same resources, such as food, light, or space. This competition typically results in more or less harmful effects to both organisms involved, as they expend energy and resources in the struggle to obtain what they need. The correct answer is 'more or less harmful effect to both.'