1. Characteristics of Life
To be considered living, an organism must…..
Be based on a universal genetic code.
DNA/RNA
Replication, transcription
2. Grow and develop- Cell division, make proteins, increase in size

2. Characteristics of Life
3. Be able to reproduce
- Asexually (binary fission)
- Sexually (conjugation, mitosis)
4. Use materials and energy
- Metabolism, respiration

3. Characteristics of Life
5. Be able to respond to their environment - Stimulus  Response
6. Maintain stable internal environment
- Homeostasis: getting rid of unnecessary materials, osmosis, diffusion, cell transport

4. Characteristics of Life
7. Change over time, as a group. -Evolution, natural selection, adaptation
8. Made of units called cells -Unicellular -Multicellular
multicellular
unicellular

5. BASIC VIRUS NOTES

6. CHARACTERISTICS OF VIRUSES
VIRUS – (POISON) DISCOVERED BY STANLEY – 1935, TMV
Viruses are pathogens—agents which cause disease
NOT NORMALLY CLASSIFIED (debate on living vs. nonliving)
CONTAIN GENETIC MATERIAL & PROTEIN
LIVE AND REPRODUCE ONLY INSIDE OTHER
LIVING CELLS
CAUSE DISEASES SUCH AS COLDS, FLU, AIDS,
SMALL POX, MEASLES, CHICKEN POX, RABIES,
MUMPS AND MONONUCLEOSIS.

7. STRUCTURE OF A VIRUS CORE OF NUCLEIC ACID AND PROTEIN COAT
PROTEIN COAT-CAPSID
NUCLEIC ACID IS EITHER DNA OR RNA

8. FIVE BASIC SHAPES OF VIRUSES
HELICAL
SPHERICAL
POLYHEDRAL
BINAL
FILOVIRUS

9. HELICAL
RNA OR DNA COILED IN A LONG NARROW CAPSID
TOBACCO MOSAIC VIRUS

10. SPHERICAL
TYPICALLY STUDDED WITH RECEPTORS, MAY BE ENVELOPED (ENVELOPE AROUND CAPSID)
INFLUENZA (FLU) VIRUS

11. POLYHEDRAL VIRUS GEOMETRIC APPEARANCE
ADENOVIRUS CAUSES THE COMMON COLD

12. BINAL
POLYHEDRAL CAPSID (DNA/RNA)
HELICAL TAIL
EX. Bacteriophage

13. FILOVIRUS NO DISTINCT UNIFORM SHAPE THREADLIKE LOOPS
FILOVIRUSFiloviridae Photo Album
EBOLA
DEADLY VIRUSES
NO DISTINCT UNIFORM SHAPE
THREADLIKE LOOPS

14. LYTIC CYCLE VIRUS ENTERS HOST REPLICATES IMMEDIATELY
PRODUCES MANY NEW VIRUSES
THESE VIRUSES INVADE OTHER CELLS

15. LYSOGENIC CYCLE VIRUS INVADES CELL DOES NOT IMMEDIATELY KILL HOST CELL
BECOMES PART OF HOST’S DNA
EVENTUALLY GOES INTO LYTIC CYCLE

16. VIRAL REPLICATION CYCLES

17. IMPORTANT TERMS
HOST –
AN ORGANISM THAT SHELTERS AND NOURISHES SOMETHING.
2. RETROVIRUS -
A VIRUS THAT REPLICATES BY FIRST TRANSCRIBING RNA INTO DNA. (HIV)

18. 3. VIROID -
A SINGLE STRAND OF VIRAL RNA. (PLANT DISEASES)
4. PRION -
VIRAL PROTEIN MOLECULE. CAUSES DISEASES IN ANIMALS. (MAD COW DI-SEASE).

19. 5. CAPSID - 6. PROPHAGE - 7. LYSIS - 8. BACTERIOPHAGE
THE PROTEIN COAT OF A VIRUS.
6. PROPHAGE -
A VIRAL DNA SEGMENT INSERTED INTO A BACTERIAL CELL
7. LYSIS -
THE BREAKING APART OF THE CELL TO
RELEASE NEW VIRUSES.
8. BACTERIOPHAGE
A VIRUS THAT ATTACKS A BACTERIA.