Shark Quiz
Questions: 16 · 10 minutes
1. A shark has a dark upper surface and a pale underside. How can this countershading help conceal it?
Both surfaces reflect bright colors that confuse prey
The pale underside makes the shark invisible on the seabed
The color pattern imitates the warning markings of venomous fish
The dark back blends with deeper water from above, while the pale underside blends with brighter water from below
2. Which field observation most strongly suggests that an animal is a shark rather than a ray?
Its body is broad and disc-shaped
Its mouth and gill openings are on the underside
Its enlarged pectoral fins are fused to the sides of its head
Its gill slits are positioned along the sides of a streamlined head
3. A shark’s skin feels rough partly because it is covered with what structures?
Overlapping bony scales
Hardened mucus plates
Flexible shell fragments
Dermal denticles
4. Which shark is the largest living shark species?
Great white shark
Basking shark
Whale shark
Tiger shark
5. A whale shark’s name can cause confusion. Which evidence correctly identifies it as a fish rather than a whale?
It lives only in salt water and has a streamlined body
It breathes through gills and has a cartilaginous skeleton
It swims with fins and travels long distances
It is very large and feeds on small organisms
6. In male sharks, claspers are primarily involved in what process?
Steering during rapid turns
Transferring sperm during internal fertilization
Detecting electrical signals from prey
Holding food while the shark bites
7. At a distance, which combination most strongly indicates that an animal is a shark rather than a dolphin?
Regular surfacing to exhale through the top of the head
A blowhole and a tail that moves mainly up and down
Visible gill slits and a tail that moves mainly from side to side
A horizontal tail used to push water vertically
8. A nurse shark remains on the seabed while continuing to breathe. Which mechanism helps make this possible?
It stores air in a lung-like chamber
It absorbs oxygen directly through its skin
It temporarily stops using oxygen while resting
It actively pumps water over its gills
9. If large predatory sharks decline sharply in an ecosystem, which change is a plausible food-web effect?
Some mid-level predators increase and place greater pressure on their prey
Plankton immediately disappears from the entire region
Every prey species increases equally
Other species remain unaffected because sharks have no ecological influence
10. Which statement best reflects the fossil history of sharks?
Shark ancestors existed before the earliest known trees
Sharks first appeared after modern whales evolved
Sharks originated at about the same time as humans
The first sharks appeared only after the extinction of non-avian dinosaurs
11. Researchers observe two enormous sharks swimming with open mouths as they strain tiny organisms from the water. Which pair best fits that behavior?
Great white shark and tiger shark
Hammerhead shark and bull shark
Whale shark and basking shark
Shortfin mako and thresher shark
12. While swimming near shore, you notice baitfish leaping, a shark-like fin nearby, and a lifeguard signaling people to exit. What is the most appropriate response?
Leave the water calmly and promptly, then follow lifeguard instructions
Splash vigorously to frighten the animal away
Remain in place because most sharks do not target humans
Swim closer to confirm the shark’s species
13. A bull shark moves from coastal seawater into a freshwater river. What ability is especially important during this transition?
Switching from gills to lungs
Adjusting salt and water balance through osmoregulation
Replacing cartilage with bone
Becoming temporarily warm-blooded
14. What forms most of a shark’s skeleton?
Dense bone
Keratin
Cartilage
A calcium shell surrounding soft tissue
15. Which sensory structures help sharks detect weak electrical fields produced by living animals?
Lateral-line scales
Ampullae of Lorenzini
Gill rakers
Spiracles
16. A leathery “mermaid’s purse” found attached to seaweed is most likely evidence of which reproductive method?
An egg-laying shark or ray depositing an egg case
A shark building a nest from shed skin
A live-bearing shark leaving a placental sac
A juvenile shark forming a protective feeding pouch