Lampreys Completely Lack Parathyroid Glands

question 79

Multiple Choice

Lampreys completely lack parathyroid glands.Suggest why these glands may be important for other vertebrates,but not for jawless fish.

• A)Because they are parasitic,lampreys get plenty of calcium from their hosts.
• B)Living in the ocean,they are surrounded by large amounts of sodium,chloride,and magnesium ions.
• C)Jawless fish employ a different system than other vertebrates to regulate blood sugar.
• D)Since they have a cartilaginous skeleton but not true bone,they have less need to regulate calcium levels.

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Definitions:

Net Operating Income

The profit a company makes from its operations, excluding non-operational revenues and expenses like interest and taxes.

Variable Costing

An accounting method that only includes variable production costs—material, labor, and overhead—in product cost calculations, excluding fixed costs.

Fixed Manufacturing Overhead

The sum of all production costs that do not change with the level of output, including salaries, rent, and utility expenses of a manufacturing facility.

Absorption Costing

An accounting method that includes both variable and fixed manufacturing overhead costs in the cost of producing goods.