The Large Spiracles on the Top of the Head of Skates

question 61

Multiple Choice

The large spiracles on the top of the head of skates and rays is 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:

Mean Weight

The average weight of a group of items or individuals calculated by summing their weights and dividing by the number of items or individuals.

Confidence Interval

A statistical range, with a given probability, that is likely to contain the true value of an unknown population parameter.

Average Speed

A measure of the total distance traveled divided by the total time taken for the trip, used in various contexts to indicate speed consistency.

Daily Tonnage

The total weight of goods or materials processed or transported in a single day.