Bob grows corn. Last year she grew 2,000 pounds of corns in a year while using 250 square feet of land and 1 worker. This year she doubled her land to 500 square feet, doubled her workers to 2, and grew 4,500 pounds of corns. She sells her rare, organic corns for $50 a pound. She pays her a worker $25,000 a year and rents her land for $100 per square foot for a year. What was Bob's total cost last year and this year?

Spider crabs live in the shallow regions of the ocean floor. algae tend to grow on the surface of spider crabs. the algae provide the crabs protection from predators by camouflaging them. the spider crabs give the algae shelter. what does this description suggest? 1. the algae are parasites of the spider crabs. 2. the algae and the spider crabs have a mutualistic relationship. 3. the spider crabs are commensals, and the algae are parasites. 4. the spider crabs benefit from the algae living on them. 5. the spider crabs are parasites of the algae.