) Why is it important to aquatic life (in ponds and lakes) that water freezes top down?

If ice were to form from the bottom of a lake or pond upwards, all life in that water would eventually freeze and die. Freezing of water from the top down is critical for aquatic life to survive in brutally cold winters, since surface ice actually helps insulate and slow the cooling of the water below.

answers are:

lysogenic     viral dna merges with host cell dna

lysogenic     no symptoms

lytic               viral dna takes over

lysogenic     virus does not destroy host cell

lytic               virus destroys host cell

lytic               induces symptoms of viral infection

lysogenic       cell reproduces and spreads provirus