Imagine a system where a finch feeds on thistle seeds and the finch population size is linked to the productivity of the thistle, and the thistle population size is related to foraging pressure of the finch population. this is an example of population dynamics at the level. (a) population. (b) community. (c) ecosystem. (d) species.

Community.

Explanation:

Community may be defined as a group of population of two or more different species in a ecosystem. These population occupy the same geographical area and may or may not share the same resources.

The finch feeds on thistle population and the thistle population size is related to foraging pressure of finch population. Here, two populations are interacting with each other, this is a case of community.

Thus, the correct answer is option (B).

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the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.