A Neural Tube Defect May Be Caused by a Maternal

question 24

True/False

A neural tube defect may be caused by a maternal lack of vitamin A.

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Definitions:

Food Webs

Complex networks of predators and prey showing the feeding relationships between organisms within an ecosystem.

Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment, chiefly involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, decay of organisms, and the burning of fossil fuels.

Trophic Levels

The levels in an ecosystem, representing a step in the food chain or food web, characterized by organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.

Natural Food Chains

A sequence of organisms each dependent on the next as a source of food, demonstrating the flow of energy and nutrients in an ecosystem.