Exam 9: Biodiversity of Invertebrate Animals and Biodiversity of Plants

Seeds within edible fruits are often dispersed through

After reading the paragraphs below, answer the question(s) that follow(s). Scientists believe that a shift from pollination by insects to pollination by birds occurred several times over the course of angiosperm evolution. Two researchers designed an experiment to investigate how these shifts might evolve using two species of monkey flower (Mimulus spp.). M. lewisii has violet-pink flowers and is pollinated by bumblebees. M. cardinalis has orange-red flowers and is pollinated by hummingbirds. The researchers switched flower-colour genes between the two species. As a result of the gene transfer, they produced a variation of M. cardinalis with dark pink flowers (instead of the original orange-red). The new variety of M. lewisiis had orange flowers (instead of the original violet-pink). Plants of both genetically altered varieties were placed in their original habitats and observed. The genetically altered variety of M. cardinalis was visited by bumblebees 74 times more often than plants with the original colour flowers. The genetically altered variety of M. lewisii was visited by hummingbirds 68 times more often than plants with the original colour flowers. -A general conclusion of this study would be that

After reading the paragraphs below, answer the question(s) that follow(s). Corals belong to phylum Cnidaria. The reefs themselves are made up of millions of polyps, each of which secretes a calcium carbonate skeleton that becomes part of the reef structure. Coral, which are attached to the reef as adults, have free-swimming larvae that develop into new polyps. Corals are actually colourless. The brilliant colours that are visible on the reef come from the zooxanthellae (microscopic algae) that live within their body tissues. The zooxanthellae and corals have a symbiotic relationship in which corals provide carbon dioxide and mineral nutrients (released as wastes from coral digestion) to the zooxanthellae. The zooxanthellae perform photosynthesis. Photosynthesis produces nutrients (in the form of sugars) for the coral and also releases oxygen. This relationship supplements energy from predation and allows corals to survive in clear tropical water, even though these areas have very low nutrient levels. -Coral bleaching occurs when the zooxanthellae are lost from the coral for a variety of reasons. What will be the important functional outcome of this for the coral?

Where does the grain that grows on sand dunes originate?

After reading the paragraphs below, answer the question(s) that follow(s). Bipedalism is one of the most important characteristics of hominin evolution. The appearance of bipedalism led to anatomical changes that are considered to be distinguishing characteristics among hominin fossils. The evidence for bipedalism is supported by fossil evidence from more than 4 million years ago and a trackway of footprints in volcanic ash 3.6 million years old. Recently, however, scientists have focused on the link between tooth structure and diet in the evolution of the early hominins, specifically in Australopithecus species. Detailed studies of hominin dental features have provided evidence of an important dietary shift that led to adaptive radiation within this genus. Most of the evidence comes from analyses of tooth size and shape, microscopic wear patterns on teeth, and jaw structure. The evidence suggests that fibrous plant materials became more important through the Pliocene, perhaps as critical components in the diet of some species. -In addition to the two typical embryonic layers, most animals have a third embryonic layer called the

Pollination is only effective when

Which of the following is true about mosses?