Question

dubautia carrii is a species in a family of plants known collectively as the silversword alliance, all of which grow only on the hawaiian islands. members of this alliance exhibit an extraordinary range of phenotypes, with some species maturing into vines and others into shrubs and trees. all species in the alliance descended from a single ancestral tarweed plant that arrived on the islands around 5 million years ago. the tarweeds descendants diversified into distinct species as they adapted to live in the wide variety of habitats found on the hawaiian islands. 3 mark for review which choice best states the main purpose of the text? a to indicate the specific tarweed ancestor of all plants that grow on the hawaiian islands and explain why the plants have such varied physical characteristics b to describe the specific habitat where dubautia carrii are found and identify other plants that share a common ancestor with them c to describe the silversword alliance and explain how the plant family became so varied d to advance the claim that all plants on the hawaiian islands are part of the silversword alliance and list possible ancestors of the plants that make up the alliance

Explanation:

• Option A: The text says the tarweed is the ancestor of the silversword alliance, not all plants on Hawaiian Islands, so A is wrong.
• Option B: The text doesn't focus on describing the specific habitat of Dubautia carrii or identifying other plants with the same ancestor in that way; it's about the alliance's diversity, so B is wrong.
• Option C: The text introduces the silversword alliance (including Dubautia carrii) and explains how their ancestor diversified into varied species, which matches this option.
• Option D: The text says the silversword alliance grows only on Hawaiian Islands, not all Hawaiian plants are in it, and it identifies the ancestor (tarweed), not list possible ancestors, so D is wrong.

Answer:

C. To describe the silversword alliance and explain how the plant family became so varied