The lancelet, fish external structure and Lab 4
Answers are for parents and teachers.
1
Compare the lancelet and a fish: heart, brain, notochord/vertebral column, breathing.
Lancelet: no heart or brain, notochord for life, gill slits. Fish: two-chambered heart, brain, vertebral column, gills.
2
Draw a carp, label its fins and write their jobs.
Tail – thrust; dorsal/anal – stability; pectoral and pelvic – turning, stopping, balance.
3
What is protective colouring? Give a fish example.
Body colour matching the surroundings to avoid predators; a fish’s dark back and pale belly.
4
How does the swim bladder raise or sink a fish?
Gas filling the bladder lifts the fish; releasing gas makes it sink.
5
Write 3 safety rules from the lab.
Do not touch fixing solutions; beware of bones; wash hands with soap afterwards.