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Biology - Diversity - Evolution

	In the response to population selection, what is being selected and what is necessary for survival?
	phenotype is being selected an organism that "works" in its environment

	What are some examples of natural selection?
	In response to predation by seed beetles, leguminous tropical trees developed defense mechanisms to insure survival of the seeds. In one species, the trees bore a few large seeds that were poisonous, while another species developed many smaller seeds escaping total dessimation through size and quantity.

	What are the implications of asexual reproduction for a plant population?
	Asexual reproduction of plants in nature are products of mitosis, creating a plant that is genetically identical to the parent plant. Without the recombination and genetic variability of seed produced plants, asexually propagated plants may be able to flourish only in a locally restricted habitat.

	What does the idea of punctuated equilibrium propose?
	The punctuated equilibrium model proposes that evolutionary changes occur during a period of rapid change alternating with a long period of gradual or no change.

	Why can't we simply arrange present day plants in an evolutionary sequence (bryophytes, ferns, conifers, angiosperms)?
	All of these groups have evolved further since their divergence millions of years ago

	What two aspects of the reproductive process do we see develop particularly among the angiosperms?
	pollination and seed dispersal mechanisms

	What are the main trends in the evolutionary development of flower structure?
	from indefinite numbers of petals stamens etc. to definite numbers from four kinds of parts to 3, 2 or 1 fusion of parts from superior ovary (hypogynous flower) to inferior (epigynous) from radial to bilateral symmetry

	Why could it be that we see greater consistency in flower structure than in vegetative structure in angiosperm families?
	rapid change in flower structure causes reproductive failure less problems in changing leaf or stem structure if pollination still works

	How does the structure of fruits relate to mechanisms of dispersal?
	fleshy fruits attract animal dispersal agents winged and "fluffy" fruits for wind dispersal hooks for animal dispersal exploding fruits

	Pollination and seed dispersal mechanisms often result from coevolution. What is another type of coevolution and what has been a secondary consequence for our use of plants?
	Biochemical coevolution: production of a great variety of chemicals (phenolics, terpenoids, alkaloids) to attract (pollinators), repel (herbivores) or kill (pathogens). Animals herbivores and pathogens evolve to exploit these mechanisms.   Spices, flavors, scents, pharmaceuticals, "natural" pesticides

What process does an RNA virus use to make multiple copies of its genome? reverse transcription transcription translation

Reverse transcription is a necessary before multiplication can begin, but only a few copies can be made and they will be DNA, not RNA as in the mature virus.   Yes, since their genetic material is passed on through RNA which can only be made (in today's world) by copying from DNA they must use transcription.   Translation is necessary to make the protein coat but this is not the critical step in multiplication.

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