Question

unit 5: marine phyla of life

1. describe in a sentence or two what happened during the cambrian period
2. review and summarize coral reef formation and coral reproduction strategies.
3. describe the difference between a polyp and medusa. which body form do corals have their entire lives?
4. what are corals, and how are they classified biologically?
5. what is the difference between hard corals and soft corals?
6. what are coral polyps, and what role do they play in coral growth?
7. what is the significance of coral reefs in marine ecosystems?
8. explain the symbiotic relationship between corals and zooxanthellae.
9. how do corals reproduce, and what are the differences between sexual and asexual reproduction in corals?
10. what is coral bleaching, and what causes it?
11. name three types of reef structures formed by corals. over time, what causes these formations?
12. how do human activities contribute to coral reef degradation?
13. why are coral reefs often called the

ainforests of the sea\?

Explanation:

To solve these questions, we'll address one (e.g., question 1) using the Answer - Explanation Format under the Natural Science (Biology) subfield.

(for question 1):
The Cambrian Period (541 - 485.4 mya) saw the Cambrian Explosion, a rapid diversification of life with most major animal phyla appearing, including marine - adapted forms, due to environmental and evolutionary factors.

(for question 8):
Corals (Cnidarians) and zooxanthellae (dinoflagellates) have a mutualistic symbiosis. Zooxanthellae live in coral tissues, photosynthesize to provide corals with organic compounds (e.g., glucose) and oxygen. Corals provide zooxanthellae with a protected environment, carbon dioxide, and nutrients (e.g., nitrogen, phosphorus) from their metabolism and waste. This relationship is vital for coral growth/color and reef health.

Answer:

(for question 1):
During the Cambrian Period, the Cambrian Explosion occurred, with a rapid diversification of life and the appearance of most major animal phyla, many adapted to marine environments.

(For other questions, follow a similar approach. For example, for question 8 - explaining the symbiotic relationship between corals and zooxanthellae: