Which of the following groups has no member having gliding or flying appendages?

Which of the following pairs of animals are jawless fishes?

In which class of animals do the larvae return to the sea after metamorphosis?

Assertion: Cyclostomates are marine but migrate for spawning to fresh water.
Reason: After spawning, within a few days they die. Their larvae after metamorphosis return to the ocean.

All the following statements are correct about $Petromyzon$ (Lamprey) except:

Which of the following statements are correct for $Cyclostomata$?
$I$ - They have a sucking and circular mouth without jaws.
$II$ - Their body is devoid of scales and paired fins.
$III$ - Their cranium and vertebral column are cartilaginous.
$IV$ - They have a closed type of circulatory system.
$V$ - $Cyclostomes$ live in freshwater, but migrate to the ocean for spawning.
$VI$ - They show direct development.