Match each description to the type of relationship it represents. 1. predator and prey
2. obligate parasitism
3. commensalism
4. facultative parasitism

-1- Rickettsia bacteria can only survive in eukaryotic cells, which are destroyed when the bacteria replicates.
-2- A freshwater amoeba feeds on bacteria in the water.
-3- A pseudoscorpion, a type of arthropod, hides under a beetle's wings for protection and transportation, but does not affect the beetle.
-4- Armillaria fungi grow within a tree's roots, causing the tree to rot, but will survive if the tree dies.

Hormones are chemical molecules produced by endocrine glands. one such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles. which two statements describe the probable reason for the function of the hormone? the cells in the heart have specific receptors that allow for the intake of hormones. the heart and the endocrine glands have the exact same types of cells. all cells make the same types of hormones. thyroid hormones show their effect on the heart by means of specialized cells. thyroid cells and cardiac cells have different dna.

What part of the cell does 9 represent? a. cytoplasm b. lysosome c. ribosome d. centrosome

What is the most common structure of volcanoes?