Unit 5: Viva / Practical Record Books / Field study
This unit covers the non-experimental, submission-based components of your practical examination. These components assess your diligence, observational skills, documentation, and overall understanding of the entire syllabus.
Botanical Excursion and Field Report
Objective
The syllabus requires a visit to an institute of microbial technology OR a visit to local vegetation to understand lower cryptogams (algae, fungi, lichens).
The Excursion Report
After the visit, you must submit a formal excursion report. This report is your scientific documentation of the trip.
Components of a Good Field Report:
- Introduction: State the aim of the visit (e.g., "To study the diversity of lower cryptogams in the [Location] area..."), the date, and the location.
- Methodology: Briefly describe how you observed and collected data (e.g., "Visual observation, collection of specimens, photographic documentation...").
- Observations: This is the main body.
- Describe the habitat (e.g., "The area was moist and shaded, ideal for fungal growth...").
- List the specimens you observed or collected (e.g., "Parmelia (Foliose lichen) was found on tree bark...").
- Include photographs or sketches of the specimens in their natural habitat.
- Discussion (if visiting an institute): If you visited an institute, describe the techniques or research you observed (e.g., "We observed the process of media preparation and sterilization in the microbiology lab...").
- Conclusion: Summarize what you learned from the visit.
Submission of Practical Record Books
Objective
The practical record book is the official, certified record that you have completed all the experiments in the syllabus. It is a major component of your practical marks.
Checklist for a Perfect Record Book:
- Completeness: Ensure every single experiment from Units 1, 2, 3, and 4 is included.
- Index: Have a neat, complete index at the front with experiment titles and page numbers.
- Structure: Each experiment should follow a clear format:
- Aim: (e.g., "To perform Gram staining on a bacterial smear from curd.")
- Principle: (The "why" of the experiment, e.g., "Gram+ bacteria have a thick peptidoglycan wall...").
- Materials Required: (List all reagents, glassware, specimens).
- Procedure: (Step-by-step, in past tense).
- Observations: (What you saw, e.g., "Rod-shaped, purple-stained cells were observed..."). This also includes calculations (e.g., for micrometry).
- Diagrams: All drawings must be on the blank/drawing page. They must be large, clear, and pencil-labeled. Label lines should be horizontal.
- Result/Conclusion: (e.g., "The bacteria from curd are Gram-positive rods.").
- Neatness: The record must be clean, with no scribbling or excessive corrections.
- Certification: Ensure your record book is checked and signed by your course instructor well before the exam date.
Viva-Voce (Oral Examination)
Objective
The viva-voce is an oral test conducted by external and internal examiners. Its purpose is to test your fundamental understanding of the practicals you performed. You cannot pass by just copying the record book; you must understand what you did.
How to Prepare for the Viva:
Go through your record book and ask yourself "Why?" for every step.
Example Questions for Each Unit:
- Unit 1 (Microbes):
- "What is the role of the mordant (iodine) in Gram staining?" (Answer: It forms a large, insoluble complex with crystal violet.)
- "Why is the decolorization step 'critical'?" (Answer: It's the step that differentiates; over-decolorizing can make a Gram+ look Gram-, and vice-versa.)
- "What is a prophage?" (Answer: The integrated viral DNA in the host's chromosome during the lysogenic cycle.)
- "Why do we autoclave media?" (Answer: To sterilize it by killing all microbes, including endospores.)
- Unit 2 (Algae):
- "You are given Chlamydomonas and Chlorella. How will you differentiate them?" (Answer: Chlamydomonas is motile with flagella; Chlorella is non-motile.)
- "What is a heterocyst and what is its function?" (Answer: A thick-walled cell in Nostoc/Anabaena for nitrogen fixation.)
- "What is a coenocytic thallus? Give an example." (Answer: Aseptate, multinucleate. Example: Vaucheria.)
- "How do you identify Ectocarpus?" (Answer: By its unilocular and plurilocular sporangia.)
- Unit 3 (Fungi/Lichen):
- "What is the function of phenol in Lactophenol stain?" (Answer: It kills the fungus.)
- "How do you identify Rhizopus vs. Penicillium under a microscope?" (Answer: Rhizopus is coenocytic with sporangia; Penicillium is septate with brush-like conidiophores.)
- "What is the difference between a foliose and a crustose lichen?" (Answer: Foliose is leafy and can be peeled off; crustose is a flat crust that cannot be removed.)
- Unit 4 (Cell Biology):
- "What is the principle of plasmolysis?" (Answer: Exosmosis of water when a cell is in a hypertonic solution.)
- "Why did the beetroot leak pigment at 70°C but not at 25°C?" (Answer: The high temperature denatured the membrane proteins and melted the lipids, destroying the membrane.)
- "How do you identify Anaphase I of meiosis?" (Answer: Homologous chromosomes separate, but sister chromatids stay together.)
- "What is the formula for calculating cell concentration with a haemocytometer?" (Answer: (Avg. cells/square) * Dilution * 10,000.)