Question

Whales have magnetite in their retinas, which aids in navigation during migration by a. piloting. b. locating the position of the Sun. c. use of the Earth's magnetic fields. d. locating the positions of the stars. e. doing none of the above.

Short answer

The correct answer is (c) use of the Earth's magnetic fields.

Step-by-step solution

Understand the role of magnetite

Magnetite is a magnetic mineral and animals like whales use it for navigation. It allows them to sense the earth's magnetic field.

Analyze the options

Going through all the options: (a) Piloting is orienting using external visual reference points which is not related to magnetite. (b,c,d) Locating position of the sun, use of earth's magnetic field, locating position of stars are navigation methods. (e) Doing none of the above is a negative statement.

Select the correct option

Since Magnetite helps sense the earth's magnetic fields, the correct choice is (c) use of the Earth's magnetic fields.

Key concepts

Magnetite

Magnetite is a fascinating mineral with magnetic properties, commonly found in various animals, including whales. This magnetic mineral can act like a natural compass, helping animals in their quest for navigation. Certain cells in animal bodies contain tiny magnetite crystals. These crystals are reactive to the Earth's magnetic fields.

It's believed that these magnetite crystals enable animals to detect their spatial orientation. Through this, they can traverse long distances much like guided by an innate GPS system. Not only whales, but birds and some fish also use magnetite for similar purposes, making it clear how evolution has integrated this mineral into superior survival tools for migratory species.

Earth's Magnetic Fields

The Earth is surrounded by magnetic fields. These fields are generated by the movement of molten iron in the Earth's outer core. You can think of it as a giant magnet laid out across the world, with a north and south pole.

Animals including whales can sense and interpret these magnetic fields. With their internal magnetite crystals, whales can perceive changes and strengths in these fields. This perception helps them steer in the right direction during migration. The Earth's magnetic fields essentially provide a map without lines, guiding these large creatures over oceans.

Migration

Migration is an awe-inspiring natural phenomenon where animals travel from one region to another, often in response to seasonal changes. For many animals, migration is essential for breeding, feeding, and survival.

Whales are famous for their long migratory journeys. They travel thousands of miles, guided by various natural cues including the Earth's magnetic fields. For these creatures, successful migration means moving to warmer waters for breeding and calving or to climates with richer feeding grounds. This journey requires precise navigation, made possible by natural tools like magnetite.

Whales

Whales are among the largest animals on our planet, and they embark on some of the most extensive migratory trips. How do these giants of the sea navigate vast, open oceans? They rely on a combination of sensory skills.

• Visual landmarks and sun position
• Acoustic cues like underwater sounds
• The Earth’s magnetic fields

Among these tools, magnetite plays a crucial role in interpreting the magnetic signals of the Earth. Whales have evolved to use all of these cues to guide their travel paths successfully.

Magnetic Minerals

Magnetic minerals like magnetite are not only significant for whales but for many other animals. These minerals are integral to comprehending how animals interact with the Earth's magnetic fields.

For instance, migratory birds have been known to possess magnetite in their beaks, assisting them in similar ways to whales. This characteristic showcases the importance of magnetic minerals in the animal kingdom. They offer a deeper understanding of the fundamental evolutionary mechanisms that facilitate animal navigation.