The role of fins in swimming Who knows the answer to the report book on biological experiments on th

Pectoral fins, pelvic fins: control balance.

Tail fin: Controls the direction of travel.

Swing of the trunk and tail fin: the driving force of the fish forward.

The tail fin swings from side to side to allow the fish to swim forward and control the direction, and the rest is used to maintain balance.

Pectoral fins, dorsal fins, and pelvic fins play a balancing role.

The anal fin plays an auxiliary role.

The caudal fin is used to determine direction and generate forward momentum.

The pectoral fins can change direction.

Categories: Education Academic Exams >> High School Entrance Examination.

Problem description:1If no simulation is chosen, the fish chosen are: - because this fish has --- characteristics.

Cord, wire, cotton, gauze, adhesive tape, thick and thin wooden boards, styrofoam, plastic sheets, etc.) 3.**Program Highlights: --4

Phenomena during the experiment: --5The results and conclusions of the experiment should be taken cautiously ((any one or two can also be used)).

Analysis: The fin of crucian carp is more obvious and easy to distinguish.

Material: Fine line, thin woodblock.

Step 1Tie the dorsal fin, pectoral fin, and pelvic fin with a thin wire to observe any abnormalities in the fish.

Note that the pectoral fins are fragile and should be tied carefully.

2.Loosen the pectoral fin, pectoral fin, pelvic fin, tie the caudal fin with a woodblock fine thread, and observe the phenomenon.

Phenomenon Hehe, this was all made a few years ago, and I almost forgot about it.

Let's talk about it.

When the dorsal fin, pectoral fin, and pelvic fin are bundled, the fish sways from side to side and cannot control the direction of travel.

When the tail fin is tied with tumbling, it is not possible to move forward.

Conclusion Dorsal fin, pectoral fin, and pelvic fin control direction.

The caudal fin generates power.

Be careful not to get too many scales off (fish will die).

My classmate killed one (we cooked it later).

The model is much simpler.

However, it is not good to study the role of the dorsal fin, pectoral fin, and pelvic fin, and it is better to study the caudal fin than live fish.

Materials: Balloons, rubber bands, straws, caudal fin-like hard plastic.

Step 1 Fill the balloon with a portion of the gas and fill it with a small amount of water.

Place the straw **balloon mouth with your hand to flatten the straw.

Tie the balloon neck tightly with a rubber band.

After folding the straw over, another rubber band should be tied tightly.

Place two stiff pieces of plastic on the tail fin around the balloon neck and tie them tightly with rubber bands.

Clamp with a return needle.

Insert a plastic knife between the two caudal fins.

Put the balloon in the water.

Press and hold the tip of the "fish" with your hand and move the plastic knife.

Observe if the fish advances.

Conclusion ......Think for yourself, it's easy to die)

Note that this experiment has failed, hehe.

But that's right.

These experiments are so easy to do, why not??

Also, during the live fish experiment, bundling the fins is not a simple thing to tie with one finger (the fish is light and slippery and difficult to catch), we starved the fish for a day, hehe, simple Dora.

Fins have the effect of maintaining the balance of the fish's body.

2. Fish fins are used by fish to defend against enemies.

3. The fin is the "beautiful coat" that attracts the attention of the fish

4. The tail fin is the "power device" for the fish to move forward

5. The tail fin determines the direction of movement.

= Dorsal and anal fins: Vertical fluctuations to keep the fish upright.

Tail fin: Swings from side to side, propelling the fish forward.

Pectoral fin: When the caudal fin is not moving, the pectoral fin opens to both sides of the fish body and swings back and forth, and the fish moves forward; When the pectoral fin swings on one side, the fish turns to the side that does not move.

Pelvic fin: The swing range is not large, slightly extended to the sides, keeping the fish stable.

Broadly speaking, the role of the fin is to be an organ of movement and balance; If interpreted in a narrow sense, the use of various fins is not the same as that of hailstones.

Tail fin: Swings from side to side, propelling the fish forward. Determines the direction of movement, and if lost, the fish will not turn.

Pectoral fin: When the tail fin is not moving, the pectoral fin opens to both sides of the fish's body and swings back and forth, and the fish body calls forward; Side.

When the pectoral fin swings, the fish turns to the side that does not move; If the balance is lost, the fish will sway from side to side.

Pelvic fin: The swing range is not large, slightly extended to the sides, keeping the fish stable.

Dorsal fin: Keeping the fish on its side plays a key role in the balance of the fish, if lost, it will lose its balance and roll over.

Anal fins: Coordinate with the other fins to play a balancing role, if lost, the body shakes slightly.