The Large Spiracles on the Top of the Head of Skates

question 25

Multiple Choice

The large spiracles on the top of the head of skates and rays are for

• A)air intake for respiration.
• B)water intake to prevent clogging the gills.
• C)detection of bioelectric fields from prey buried in the sea bottom.
• D)detection of chemical odors in the water.

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Definitions:

Autonomous Consumption

Describes the expenditure that consumers will make even when they have no income, considering it as a basic level of consumption driven by needs.

Saving

The act of setting aside money for future use, reducing current consumption.

Induced Consumption

Consumer spending that increases or decreases as a result of changes in income, as opposed to autonomous consumption that does not change with income.

Disposable Income

Income available to a household or individual after taxes have been paid, available for spending or saving.