Question

how do whales differ from fish?

whales use blowholes for breathing.
whales have scales that cover their skin.
whales develop lungs following metamorphosis.
whales reproduce through external fertilization.

Explanation:

Identify the core biological differences

Whales are mammals, whereas fish belong to distinct classes of aquatic vertebrates (such as bony or cartilaginous fish). Mammals are warm-blooded, breathe air using lungs, have hair at some stage, and nurse their young. Fish are cold-blooded, typically breathe underwater using gills, and possess scales.

Evaluate the first option

Whales, as mammals, must breathe atmospheric air. They have lungs and use a blowhole (a modified nostril located on top of their head) to breathe at the water's surface. Fish, on the other hand, extract dissolved oxygen from water using gills. This represents a fundamental difference.

Evaluate the second option

Whales have smooth skin without scales (though they may have sparse hairs). Fish typically have scales covering their skin. Therefore, the statement that whales have scales is biologically incorrect.

Evaluate the third option

Whales do not undergo metamorphosis; they develop directly in the womb and are born as miniature versions of adults. Metamorphosis is characteristic of amphibians and many invertebrates.

Evaluate the fourth option

Whales reproduce via internal fertilization and give birth to live young (viviparity). Many fish species reproduce through external fertilization, where eggs and sperm are released into the water. Thus, this statement is incorrect for whales.

Answer:

• Whales use blowholes for breathing. (Correct answer)
• Whales have scales that cover their skin.
• Whales develop lungs following metamorphosis.
• Whales reproduce through external fertilization.