Animal Kingdom: common misconceptions

If your child says… “Any division through the middle gives matching halves.”

Ask together

Would a division across the butterfly match its front with its rear?

What’s true

Bilateral symmetry has one matching left–right division; radial symmetry allows many through the central axis.

If your child says… “Water enters through the big top opening.”

Ask together

Where should an outward arrow go on your sketch?

What’s true

Water enters through ostia, the small pores, and exits through the osculum, the large opening.

If your child says… “The roundworm's cavity has a complete lining too.”

Ask together

Where is the mesoderm lining around the roundworm's gut?

What’s true

A roundworm's cavity lacks the complete mesoderm lining that defines a coelom.

If your child says… “The snail moves with its mantle.”

Ask together

Which broad part slides against the ground?

What’s true

The muscular foot supports movement; the mantle is a covering fold.

If your child says… “A sea star has the same symmetry throughout life.”

Ask together

Does this adult outline tell us what its larva looks like?

What’s true

Sea-star larvae have bilateral symmetry, with matching left and right halves. Adults have radial symmetry, with parts arranged around a centre.

If your child says… “The main nerve cord is solid and underneath.”

Ask together

Which structure is hollow and above the supporting rod?

What’s true

A chordate's main nerve cord is single, hollow and dorsal, above the notochord.

If your child says… “The air bladder does the breathing.”

Ask together

Which structure meets the surrounding water beneath the cover?

What’s true

Gills exchange gases with water; the air bladder helps a typical bony fish control floating depth.

If your child says… “An animal must fly to be a bird.”

Ask together

Does staying on the ground remove a bird's feathers?

What’s true

An ostrich remains a bird because it has feathers, despite being unable to fly.