BT102 Final Term Current Solved Questions Set 2 by Arif Khan

Bt102 Current final term Questions solved by M Arif

khan. (2021)

Q1. What is reverse transcription? 2marks

Answer: A reverse transcriptase is an enzyme used to generate complementary DNA from an RNA template, a process termed reverse transcription.

Q2. What is epidemiology? Write the study method of epidemiology. 3-marks

Answer: Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations. The application of this study to the control of health problems

Following are the broad categories of epidemiological studies;

• Cross-sectional studies.
• Case-control studies.
• Cohort studies.
• Intervention studies

Q3. Explain the following terms.( 5-10marks)

Phaeophyta (Kelp):

• Commonly known as brown algae.
• Brownish in color and contains cellulose aliginic acid cell walls.
• Multicellular and contain chlorophyll a and c, xanthophylls. These store carbohydrates and are used for algin.

Rhodophyta.

• Reddish in color.
• Contains Cellulose cell walls.
• Most are Multi-cellular
• Contains Chlorophyll a and d, phycobiliproteins.
• Store glucose polymer.

Chlorophyta.

• It is a Green algae
• It contains Cellulose cell walls
• These are Unicellular or multi-cellular
• Contains Chlorophyll a and b
• Store glucose polymer
• Rise to terrestrial plants

Bacillariophyta.

• These are Brownish in color
• Contains cell wall which is composed of Pectin and silica.
• These are Unicellular.
• Contains Chlorophyll a and c, carotene, xanthophylls.
• Bacillariophyta Store oil and Fossilized diatoms formed oil.
• Produce domoic acid.

Dinoflagellata.

• These are Brownish in color.
• Contains Cellulose in plasma membrane.
• These are Unicellular.
• Contains Chlorophyll a and c, carotene, xanthins.
• Store starch.
• Some are symbionts in marine animals.
• Neurotoxins cause paralytic shellfish poisoning

Q4. Explain Natural immunity, Aquired active and passive immunity. 3mrks

Natural immunity: Immunity that is naturally existing. Natural immunity does not re quire prior sensitization to an antigen.

Aquired Active Immunity: Acquired active immunity occur when the individual is introduced to a live microorganism, develops the disease and gets safe due to the fundamental safe response. Once a microbe penetrates the body's skin, mucous membranes, or other primary defenses, it interacts with the immune system.

Passive Immunity:

Passive immunity is protection from a disease provided by antibodies created outside of the body. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta.

Q5. What is Plaque? 2marks

Answer: Plaques are equivalent to bacterial colonies. Basically a plaque is an area where the virus infection has lysed the cells. These plaques are formed on cultured cells in a culture dish. Plaques can be counted easily much like bacterial colonies. e.g: Dental plaque is an example of bio-film.

Q6. What is hypersensitivity? Explain its types? 5-marks

Answer: Answer: Hypersensitivity refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity.

Types: Following are the four types of hypersensitivity;

Type-I hypersensitivity: Type-1 hypersensitivity reaction is an allergic reaction provoked by reexposure to a specific type of antigen referred to as an allergen. The reaction may be either local or systemic. Its examples are Asthma and dermatitis.

Type-II hypersensitivity: Type II hypersensitivity reaction refers to an antibody-mediated immune reaction in which antibodies (IgG or IgM) are directed against cellular or extracellular matrix antigens with the resultant cellular destruction, functional loss, or damage to tissues.

Type-III hypersensitivity: Type III hypersensitivity occurs when there is an excess of antigen, leading to small immune complexes being formed that fix complement and are not cleared from the circulation. It involves soluble antigens that are not bound to cell surfaces

Type-IV hypersensitivity: Type IV hypersensitivity, also called delayed-type hypersensitivity involves T-cell antigen interactions that cause activation and cytokine secretion. This type of hypersensitivity requires sensitized lymphocytes that respond 24–48 h after exposure to soluble antigens.

Q7. Name the drugs which resist cell wall? 2marks

Answer: Penicillin and cephalosporin are the major drugs (antibiotics) that inhibit bacterial cell wall synthesis. They are called beta-lactams.