Test your learning
1. what are the functions of bone?
2. describe the structure of bone.
3. what is the periosteum, and what are its functions?
4. describe the functions of red marrow.
5. what is ossification?
6. list the parts of the axial skeleton and the appendicular skeleton.
7. name the five types of joints and give an example of each.
8. how are bones held together at movable joints?
9. what is the function of synovial fluid?
10. describe the structure of striated muscle.
11. what is the source of energy for muscle contraction?
12. how does skeletal muscle contract?
13. how is skeletal muscle connected to bones?
14. why do muscles work in pairs?
15. define the terms flexor and extensor.

Sea levels are rising due to climate change while increasing numbers of people are moving into coastal areas. to accommodate more people, there has been increased construction of beachfront resorts and condominiums. how is this impacting sea turtle numbers and biodiversity and why? a. the increased human population in coastal areas has meant that more food is available to the turtles (e.g., dropped food, waste from restaurants), which has led to an increase in the numbers and diversity of sea turtles. b. there has been very little change in the numbers and biodiversity of sea turtles because the planet is so vast that they can simply relocate to less crowded beaches. c. this has resulted in a decrease in numbers and diversity of sea turtles because it is restricting available nesting sites, and hence reproduction. d. this has resulted in an increase in numbers and diversity of sea turtles because people are around to protect them from natural predators.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere

Why did adult crab numbers decline in he ecosystem, even though sea stars were still available?