Science Homework Help

Identify and characterize the diversity of life at the phylum level and critically evaluate the hypotheses regarding the overarching phylogenetic patterns. Each response should be 250-350 words Your answers must be in your own words (although specific jargon can be used). Student demonstrates mastery of the concept, uses biological vocabulary correctly and provides evidence/examples when appropriate. The answer is accurate and thorough, but avoids superfluous information.

**Be able to visually identify representative species from the phyla we covered this semester. Emphasis will be placed on Kingdom Animalia and Kingdom Plantae.

Question 1 Evolutionary biologists study a process that, for the most part, none of us were around to witness! What is the evidence that these scientists collect to make inferences about the diversification of life on this planet? Provide at two examples from the animal diversification presentations. Be sure to explain how the evidence used connects to the inferences made in each case.

Question 2 What are homeobox genes? How do patterns in the evolution of these genes show shared ancestry among all animals? How do the patterns show divergence? As you know, arthropods possess a variety of different mouth parts; since homeobox genes control the development of the head region, scientists have argued that they were instrumental in driving the diversification of arthropods. Imagine a single group of arthropods with the same mouth parts and explain the steps that might have followed to give rise to the diversity we see today.

Question 3 Explain how sympatric speciation occurs among cichlid species living in Lake Victoria. Some areas of the lake experience extreme runoff from developed areas which dumps sediment in the water, making it cloudy. How might this impact the reinforcement of reproductive barriers and what are the consequences? Discuss how other environmental variables might impact the process of speciation.

question 4 Contrast the flower characteristics that attract bats, hummingbirds, and bees. What features of their sensory system are responsible for these patterns? Describe coevolution and a specific example of how one of these pollinators might drive the evolution of flower characteristics in plants. How would one go about testing a hypothesis about coevolution driving speciation?

Question 5 Plants, which evolved from an algae ancestor who was obligately aquatic, consist of clades that are increasingly well adapted to the challenges of life on land. Provide examples of the progression, explaining how traits increased fitness for plants that possessed them. How might some of these traits lead to diversification over time?

Question 6 Mutualistic interactions between land plants and mycorrhizal fungi are found in nearly every plant clade. What are the benefits each organism derives from this relationship? What is the significance of this relationship to plants as they made the transition on to land? How might this relationship cause diversification in fungi?

Question 7 How do bacteria and protists differ? Explain how serial endosymbiosis was significant to the evolution and diversification of protists. Despite their lack of complexity relative to protists, bacteria are the most diverse group of organisms on the planet. What features have contributed to their diversification? Explain.