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Part A: design a food chain with four trophic levels, and identify the organism in each level. Part B: Can humans ever occupy the lowest, or first, trophic level?

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One example of ecological interaction in the ocean is the relationship between boxer crabs and sea anemones. In this unique relationship, the crabs "wear" the stinging anemones on their claws as an extra level of protection from predators. The anemones are then free to eat any leftovers from the crab's meal.
Part A: Identify which type of symbiotic relationship the above example is. (1 point)
Part B: In a parasitic type symbiotic relationship, one species of the pair is harmed. Make a fictional change to one of the members of the boxer crab/sea anemone relationship so that it becomes a parasitic relationship. Describe what that change is. (3 points)

The collared lizard is a species found in the desert southwest. male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. your tentative explanation is that male color plays a role in attracting females for mating purposes. you predict that females will preferentially choose brightly colored males over dull-colored ones. to test this prediction, you observed the interactions of female collared lizards with their male counterparts. you selected males that were the same age and size, and that differed only in their coloration pattern. you placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. in 3 instances, the females did not mate with either type. create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. on the y-axis, plot the frequency with which each type of male was chosen by females. using this graph, answer the following question(s). is it reasonable to conclude (i. e., is it supported by the data) that female collared lizards prefer more brightly colored male lizards over dull-colored males?

Hey me with this one❤❤❤❤ every organism needs food. does a cell also need it? explain very briefly.

If a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?