Which of the following statements is not true for retroviruses
The gentic material in mature retroviruses in $RNA$
Retroviruses are causative agents or certain kinds of cancer in man
$DNA$ is not present at any stage in the life cycle of retroviruses
Retroviruses carry gene for $RNA-$ dependent $DNA$ polymerase
Which of the following would be easily fossilized
Connecting link between Annelida and Mollusca is
$A$ : Lycaenops is a connecting link between reptiles and mammals.
$R$ : In permian period there was origin of mammal like reptiles.