Aquatic and marine dead zones can be caused by increases in nitrogen and phosphorus in the water from human waste or fertilizer. these substances encourage algal blooms. although algae produce oxygen in the daytime by photosynthesis, during the night hours they continue to undergo cellular respiration and use up available oxygen. when algal blooms die off, more oxygen is used during decomposition of the dead algal cells. both of these processes can result in a significant depletion of dissolved oxygen in the water, creating dead zones. dead zones can be caused by natural or human factors. a. summarize the role of algal blooms in disrupting the health of aquatic ecosystems.

Me brainliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula.5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects.8. describe the planets’ orbits around the sun.9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets.13. what causes the seasons?

Which tool could you see a plant cell? a. a filter b. a microscope c. a microwave d. an electromagnet

Label all the places where dna is located in the plant cell and in the animal cell. dna