Biology 11

INTRODUCTION TO VIRUSES

  1. List several characteristics that biologists use to classify things into living or non-living categories.
  1. Should viruses be classified as living?

YES:______

NO: ______

Summary: ______

  1. Label the diagrams of viruses as fully as possible. Use terms such as MEMBRANOUS ENVELOPE, PROTEIN CAPSID, NUCLEIC ACID CORE, SURFACE PROTEINS, DNA, RNA, HEAD, TAIL FIBRE

VIRUS ANATOMY(Text 482, SG 29-30)

Describe briefly each of the following:

  • Nucleic acid core ____DNA OR RNA MOLECULE THAT CARRIES THE GENETIC INFORMATION FOR VIRAL REPRODUCTION______
  • Capsid ____PROTEIN SHELL AROUND THE NUCLEIC ACID, VARIOUS FUNCTIONS
  • Antigens ______PROTEIN MOLECULES THAT IDENTIFY A CELL OR INVADER AS FRIENDLY OR DANGEROUS TO THE BODY’S IMMUNE SYSTEM (Antibodies bind antigens)

VIRUS ‘LIFE’-CYCLES (Text 484-485 SG 30-31)

Use the space below to draw diagrams and make notes on the LYTIC and LYSOGENIC CYCLES of viruses.

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

______

What is the main difference between these two cycles? ____IN LYSOGENIC CYCLE THE GENETIC MATERIAL IS REPLICATED AND LIES DORMANT IN MANY CELLS UNTIL ACTIVATED; THEN LYTIC.

What is viral specificity? ____VIRUSES CAN ONLY INFECT AND ATTACK SPECIFIC HOST CELLS, e.g. HIV attacks T-cells

VIRAL INFECTIONS (Text 486-487, SG 31-32)

Viruses often attack humans. The body has defenses against these attacks. What are the following?

  • Primary line of defense

____SKIN AND ITS SPECIALIZATIONS

  • Secondary line of defense

______PHAGOCYTES (EATING CELLS) WHITE BLOOD CELLS OF IMMUNE SYSTEM

  • Tertiary line of defense
    ______LYMPHOCYTES PRODUCE ANTIBODIES TO ATTACH TO ANTIGENS OF VIRUSES AND FORM CLUMPS FOR DESTRUCTION; ALSO INTERFERON COATING OF CELLS TO ‘HIDE’ CELLS FROM VIRUSES; ETC.

What can we do to help the body fight viral infections? Mention VACCINATION, ACTIVE AND PASSIVE IMMUNITY.

VACCINATION IS INJECTION OF SUBSTANCES TO PROVIDE IMMUNITY AGAINST VIRAL OR BACTERIAL ATTACK

ACTIVE IMMUNITY: WEAKENED, DEAD VIRUSES INTRODUCED TO BODY TO AROUSE BODY’S IMMUNE SYSTEM;PRODUCES MILD INFECTION AND BODY ‘REMEMBERS’ ANTIGEN FOR FUTURE ANTIBODY PRODUCTION

PASSIVE IMMUNITY: INJECTION OF ANTIBODIES

Name some common viral infections in humans.

______

Can antibiotics help against viral infections? ______

RESEARCH TASK: VIRUSES

In a maximum of one two-sided letter-sized page, present your research on one of the following topics.

  1. Research a common or unusual viral disease (HIV, Measles) and describe it in terms of
  • How infection occurs
  • Symptoms
  • Treatment
  • Prognosis
  • Impact of disease on human population (history)
  • Potential future research areas/treatments
  1. How viruses can be used in genetic engineering
  2. Any topic on viruses you suggest and teacher approves.

Present research in pamphlet or plain paper format by end of class on Tuesday, October 5.

ASSESSMENT:

Correctness of content10

Neat, attractive presentation 5

Citing of sources, use of original language 5