Baleen whales feed by doing what?

Straining small prey from mouthfuls of water through plates of keratin

Crushing shellfish between flattened molar teeth

Spearing individual fish with a single elongated tooth

Grazing seaweed and algae from shallow rocks

Echolocation in toothed whales works by what means?

Emitting rapid clicks and interpreting the echoes that return

Sensing electrical fields given off by prey

Detecting small changes in water temperature

Following chemical trails left in the water

What distinguishes a true seal from a sea lion?

True seals have no external ear flaps and cannot rotate their hind limbs forward

True seals are always considerably larger

Sea lions live only in fresh water

True seals give birth at sea rather than on land

Sea otters stay warm in cold water without a thick layer of blubber by relying on what?

An exceptionally dense fur coat that traps a layer of air

A very high-fat diet and nothing else

Long periods basking on sun-warmed rocks

Slowing the heartbeat almost to a stop

Why do diving seals and whales avoid the decompression sickness that can affect human divers?

They exhale before diving and let the lungs collapse, so little nitrogen dissolves into the blood

They breathe a different mixture of gases at the surface

Their blood is chemically unable to dissolve nitrogen

They ascend far more slowly than any human diver

Spermaceti, the waxy substance in a sperm whale's head, was historically valued for what?

Making smokeless candles and fine lubricating oils

Preserving meat on long voyages

Grey whales and humpbacks make long seasonal migrations chiefly in order to do what?

Breed and calve in warm water while feeding in cold water

Ride ocean currents that carry them along passively

Escape parasites that occur only at high latitudes

Reach river mouths where they can drink fresh water

Polar bears are usually classed as marine mammals because of what?

They depend on sea ice for hunting and spend much of their lives out on it

They give birth and nurse their young underwater

They have webbed hind flippers rather than feet

They are unable to survive for long on land

How is this quiz scored?

Every correct answer adds to your score, and there is no penalty for a wrong one. Your result is shown at the end with a full review of each question.

Do I need an account to play?

No. Every quiz is free and playable without signing in. An account is optional and only used to save your progress across devices.

Are explanations included?

Yes. Every question is followed by a short explanation of why the correct answer is right, so the quiz is useful whether you score well or not.

Oceans & Marine Life Medium ⚡ 10 Questions ⏱️ ~6 Mins +100 XP

Marine Mammals and Their Ways

Q: Can I retake this quiz?

Yes. You can replay any quiz as many times as you like, and the questions and answer options are reshuffled each time.

Several separate groups of land mammals went back to the water, and each solved the same problems in a slightly different way.

Start Quiz

Questions

~6m

Duration

Medium

Difficulty

+100

Max XP

About this topic

Mammals returned to the sea at least four times, and the groups involved are not close relatives. Whales and dolphins descend from hoofed land animals; seals and sea lions from carnivores related to bears and otters; manatees and dugongs from the same ancestry as elephants; sea otters from the weasel family. Each lineage had to solve the same list of problems from scratch — staying warm, holding a breath, drinking without fresh water, and giving birth to an air-breathing young. The solutions differ in revealing ways. Most groups insulate with blubber; the sea otter does it with fur so dense it traps a layer of air. Whales hunt by sound because sound carries well and light does not. Diving physiology in seals and whales runs almost the opposite way to a human diver's, with the lungs deliberately emptied rather than filled. The questions here cover feeding, senses, diving and migration.

Questions & answers

Marine Mammals and Their Ways: all 10 questions and answers

Every question in this quiz is listed below with its correct answer and the reasoning behind it. Play first if you would rather not see the answers — or read through as a study sheet.

Play it instead

Show all answers and explanationsHide answers

1Baleen whales feed by doing what?
- A Grazing seaweed and algae from shallow rocks
- B Straining small prey from mouthfuls of water through plates of keratin Correct
- C Crushing shellfish between flattened molar teeth
- D Spearing individual fish with a single elongated tooth
Answer: B. Straining small prey from mouthfuls of water through plates of keratin

Why: The plates hang from the upper jaw and fray into a bristly mat along the inner edge. Toothed whales, the other main group, take prey one animal at a time.
2Which whale carries a long spiral tusk that is really an overgrown tooth?
- A The narwhal Correct
- B The beluga
- C The minke
- D The pilot whale
Answer: A. The narwhal

Why: It is usually the left canine of a male, grown out through the lip, and it is packed with nerve endings that may sense the water around it.
3Echolocation in toothed whales works by what means?
- A Sensing electrical fields given off by prey
- B Detecting small changes in water temperature
- C Following chemical trails left in the water
- D Emitting rapid clicks and interpreting the echoes that return Correct
Answer: D. Emitting rapid clicks and interpreting the echoes that return

Why: The clicks are focused by a fatty structure in the forehead called the melon, and the returning sound is picked up through the lower jaw rather than the ears.
4Which group of marine mammals includes the manatee and the dugong?
- A Cetaceans
- B Mustelids
- C Sirenians Correct
- D Pinnipeds
Answer: C. Sirenians

Why: They are plant-eaters that graze on seagrass, and they are more closely related to elephants than to seals. The group name comes from the sirens of Greek myth.
5What distinguishes a true seal from a sea lion?
- A True seals give birth at sea rather than on land
- B True seals have no external ear flaps and cannot rotate their hind limbs forward Correct
- C True seals are always considerably larger
- D Sea lions live only in fresh water
Answer: B. True seals have no external ear flaps and cannot rotate their hind limbs forward

Why: That limb difference is why a sea lion can walk on all fours on land while a true seal has to hump along on its belly.
6Sea otters stay warm in cold water without a thick layer of blubber by relying on what?
- A An exceptionally dense fur coat that traps a layer of air Correct
- B A very high-fat diet and nothing else
- C Long periods basking on sun-warmed rocks
- D Slowing the heartbeat almost to a stop
Answer: A. An exceptionally dense fur coat that traps a layer of air

Why: Their fur is the densest of any mammal, and they groom constantly because matted or oiled fur loses the trapped air and the insulation with it.
7Why do diving seals and whales avoid the decompression sickness that can affect human divers?
- A They breathe a different mixture of gases at the surface
- B Their blood is chemically unable to dissolve nitrogen
- C They ascend far more slowly than any human diver
- D They exhale before diving and let the lungs collapse, so little nitrogen dissolves into the blood Correct
Answer: D. They exhale before diving and let the lungs collapse, so little nitrogen dissolves into the blood

Why: Their oxygen store is carried in the blood and muscle instead of the lungs, helped by very high concentrations of the pigment myoglobin.
8Spermaceti, the waxy substance in a sperm whale's head, was historically valued for what?
- A Fixing dyes in woollen cloth
- B Preserving meat on long voyages
- C Making smokeless candles and fine lubricating oils Correct
- D Tanning and softening leather
Answer: C. Making smokeless candles and fine lubricating oils

Why: Demand for it drove much of the nineteenth-century whaling industry, and it was later used to lubricate precision machinery and instruments.
9Grey whales and humpbacks make long seasonal migrations chiefly in order to do what?
- A Reach river mouths where they can drink fresh water
- B Breed and calve in warm water while feeding in cold water Correct
- C Ride ocean currents that carry them along passively
- D Escape parasites that occur only at high latitudes
Answer: B. Breed and calve in warm water while feeding in cold water

Why: Cold seas hold far more food but are punishing for a newborn with little blubber, so calving grounds sit thousands of kilometres from feeding grounds.
10Polar bears are usually classed as marine mammals because of what?
- A They depend on sea ice for hunting and spend much of their lives out on it Correct
- B They give birth and nurse their young underwater
- C They have webbed hind flippers rather than feet
- D They are unable to survive for long on land
Answer: A. They depend on sea ice for hunting and spend much of their lives out on it

Why: Their main prey is seals taken at breathing holes and ice edges, and they swim well enough to cross stretches of open water between floes.

Read alongside this quiz

How animals solve the problems we all have

Staying warm, finding the way home, sleeping safely. Every species faces the same short list, and the answers are inventive.

6 min read

Frequently Asked Questions

How is scoring calculated for this quiz?

Each correct answer awards 10 XP. There is zero point penalty for incorrect guesses, encouraging learning through exploration.

Can I retake this quiz?

Yes! You can retake any quiz as many times as you like, or use the Practice Mistakes mode at the end to review questions you missed.

Are explanations provided for every question?

Absolutely. As soon as you select an option, QuizKite displays a detailed explanation card explaining why the answer is correct.

QuizKite Quality Guarantee

Every quiz on QuizKite is researched, written and fact-checked by hand against reliable references, with an explanation for each answer. Read our full Editorial Policy to learn more about our content standards.

Keep going