Question

A line on a map joining places of equal salinity is called an_________.
a.Isohyet
b.Isotherm
c.Isohaline
d. Isobar

Answer 1

Hint: The lines on a map are called contour lines. Salinity is the amount of saltiness or amount of salt dissolved in a body of water.

Complete answer: Isohaline is the line on a map of the ocean connecting all points of equal salinity. It appears in oceans, seas and lakes.
Looking at the above options:
Option a: Isohyets are lines drawn on a weather map connecting points that receive equal amounts of precipitation during a given period of time. This option is incorrect.
Option b: Isotherms are lines on the map joining places of equal temperature. They are often used on weather maps by meteorologists. This option is incorrect.
Option c: Iso means 'same' and haline means 'salinity'. Thus, Isohaline joins all points or contours having the same 'salinity in an aquatic system'. The changes in salinity, changes the pattern of drawing lines. The change in salinity aids in studying the change in aquatic life. This is because salinity is a significant factor in determining the chemical alterations of water and biological processes. This option is correct.
Option d: Isobars are lines on a map connecting points having the same atmospheric pressure at a given time. This option is incorrect.

Hence, the correct answer is option c.

Note: -The salinity for normal open ocean ranges between 33 and 37.
-Salinity of oceans depends on evaporation and precipitation.
-Surface salinity is greatly affected in coastal regions by the freshwater flow from rivers, and in polar regions by the methods of freezing and thawing of ice.