Isolated and purified hepatitis B virus surface antigen can be used to synthesize ________ vaccine.

Activation of C3a results in ________.

Some antimicrobial chemicals are considered disinfectants and antiseptics.

All of the following contribute to a pathogen's pathogenicity except:

A patient infected with a new virus shows strong NK-cell activity on day 2 but no CTL response yet. Which is the best explanation?

The classical pathway for complement activation is initiated by:

Differentiate exotoxins and endotoxins in the following aspects (5 points): 

Source – Which types of bacteria produce each?

Chemical composition – What are they made of? 

Heat stability – Are they heat-stable or heat-labile?

Toxicity and lethality – Which is more potent and lethal, and why?

Mechanism of action – How are they released? How do they cause damage to host cells?

Examples of diseases – Name at least one disease caused by each.

Define normal microbiota and explain their significance to human health. Address the following points (4 points):

Definition – What are normal microbiota, and where are they commonly found in the human body?

Example – Provide one example of a normal microbial species and the body site it inhabits.

Factors influencing composition – Identify at least 3 factors that affect the composition of the normal microbiota 

Health role – Describe 2 beneficial functions of normal microbiota in maintaining human health 

Choose 2 out of the 3 questions to answer. If you answer all 3, the last question will automatically be skipped for grading. (4 points each, 8 points in total)

 a, Select one DNA or RNA virus family and a representative human virus from that family. Describe:

The virus family name and genome type (DNA/RNA, single or double-stranded, enveloped or non-enveloped).

The disease(s) it causes and its main route of transmission.

Whether the infection is acute, chronic, latent, or persistent, and how this relates to its viral replication mechanism.

One treatment or prevention strategy (e.g., antiviral, vaccine, or public health measure) and why it is effective.

b. Define the term virulence as it applies to a pathogen, and explain how it contributes to disease severity. Address the following points:

Definition – What is virulence, and how is it different from pathogenicity?

Factors influencing virulence – Name 4 pathogen traits that affect virulence 

Mechanisms countering host defenses – Name and explain at least two ways pathogens increase virulence by evading or resisting host defenses 

Example – Provide one pathogen example that demonstrates one or more of these virulence factors.

c. Differentiate between vertical and horizontal gene transfer in bacteria. Address the following points:

Definition and direction of transfer

Vertical gene transfer: describe how genetic material is inherited from parent to offspring during reproduction.

Horizontal gene transfer: name and briefly describe the three main mechanisms. 

Bioengineering application -- Identify which process is most commonly used to create recombinant bacteria and explain why it is useful in genetic engineering.

Scientists are concerned that bacteria will be resistant to all antibiotics within the next decade. 

Explain how bacterial populations can develop drug resistance in a short period of time. You may discuss the mechanisms of resistance, genetic factors, population dynamics, etc.

Name and explain at least two strategies to reduce antibiotic resistance.