Nitrogen Stable Isotopes Are Useful Tools for the Study of Food

question 7

Multiple Choice

Nitrogen stable isotopes are useful tools for the study of food web structure because isotope ratios

• A) change in predictable ways across trophic levels.
• B) often vary among alternative food sources for a consumer.
• C) for a predator exactly match the isotope ratio in its prey.
• D) both change in predictable ways across trophic levels and often vary among alternative food sources for a consumer.

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Definitions:

Leukocyte

Leukocytes, also known as white blood cells, are cells of the immune system involved in protecting the body against both infectious disease and foreign invaders.

Erythrocyte

A red blood cell, which is responsible for carrying oxygen from the lungs to the body's tissues and carbon dioxide as a waste product back to the lungs.

Parietal Layer

The outer layer of the membranes surrounding organs within body cavities, particularly in the pleura, pericardium, and peritoneum.

Glomerulus

A cluster of tiny blood vessels in the kidneys where blood filtration begins.