VIRUSES WHAT IS A VIRUS SUBMICROSCOPIC SUPER SMALL

VIRUSES

WHAT IS A VIRUS? SUBMICROSCOPIC (SUPER SMALL) PARASITE THAT INFECTS ANIMAL, PLANT, OR BACTERIA CELLS

VIRUS STRUCTURE Essentially a protein packet containing either RNA or DNA Typically has RNA

TYPES OF VIRUSES Animal Viruses – infect animals Plant Viruses – infect plants Bacteriophage – infect bacteria

VIRUS LIFE CYCLE Lytic – the Viral RNA/DNA take over the cell, makes copies of itself, then lyses the cell (this kills the host cell). Lysogenic – Viral RNA/DNA is added to the host DNA, so that it can be passed down to the next generation of cells.

HOW DO WE STOP A VIRUS? • • • Our immune system (over time) learns how to identify different viruses When a virus is recognized, it is tagged by the immune system and an alarm in the body is sounded Helper T- cells then seek out and kill the invading virus.

ARE VIRUSES ALIVE? To be considered alive it must be able to…. 1. Obtain and use energy 2. Reproduce on its own (not via a host) 3. Are made of cells There are more, but you do not need to worry about those right now.

ARE VIRUSES MORE CLOSELY RELATED TO EUKARYOTES OR PROKARYOTES? WHY?

DESCRIBE VIRAL REPRODUCTION • IN A PARAGRAPH, EXPLAIN THE PROCESS OF VIRAL REPRODUCTION. WHICH CYCLE DO YOU THINK IS MOST HARMFUL? EXPLAIN.

DESCRIBE THE ROLE OF VIRUSES IN CAUSING DISEASES SUCH AS HUMAN IMMUNODEFICIENCY VIRUS (HIV) AND INFLUENZA • EXPLAIN IN 1 PARAGRAPH

HOW CAN WE PREVENT GETTING VIRUSES? • EXPLAIN ANY PRECAUTIONS WE CAN TAKE, IN 1 PARAGRAPH