Sample Qs-Blood clotting mechanism

1. Diagram shows a body defence mechanism.

Rajah menunjukkan satu mekanisme pertahanan badan.

(a) Explain the body’s response towards the entry of bacteria into the body.

Terangkan gerak balas badan terhadap kemasukan bakteria ke dalam badan. [4 m]

(b) Microorganisms are very useful in medicinal field. They are widely used in

biotechnology in producing substances to fight against diseases.

Explain this statement by using two examples of the application.

Mikroorganisma adalah sangat berguna dalam bidang perubatan. Mikroorganisma

digunakan dengan meluas dalam bioteknologi bagi menghasilkan bahan untuk

melawan penyakit.

Terangkan pernyataan ini dengan menggunakan dua contoh aplikasi. [ 6m]

Courtesy from SBP TRIAL 2010-

SUGGESTED ANSWER:

(a)

- Pathogens / bacteria succeed in penetrating the skin / first line of

defence.

-Chemicals / proteins / antigens (produced by the pathogens)

- Attract the phagocytes / neutrophils / macrophages / monocytes

(to the infected area)

-By using pseudopodia

- Surround / engulf / kill / destroy the pathogens / bacteria

-by lysozymes / lysosomes.

-A non-specific immune response.

(b)

Example 1

-The production of insulin.

-Insert human gene (which controls the synthesis of insulin) into bacteria

-Bacteria are cultured / multiplied

-Insulin produced (by bacteria is collected).

Any 3

Example 2

-The production of antiserum.

- (Specific) antigens / pathogens are injected into an animal.

-The animal produces (specific) antibody

-Antiserum is extracted / taken (from the animal’s blood).

-To stimulate passive immunity (in humans).

Any 3

Example 3

- The production of vaccine.

-(A suspension) containing weakened / dead antigens / pathogen.

-Injected into human (body / blood)

-To stimulate the production of antibody (actively) // to achieve

-active immunity.

Any 3

Example 4

-The production of antibiotics.

-Chemicals produced by microorganisms / Penicilium notatum /

-Streptomyces to kill other microorganisms / bacteria.

-Example: penicillin / streptomycin.

-Penicillin is used to treat gonorrhea / syphilis / lung infection.

-Streptomycin is used to treat tuberculosis / TB.

Any 3