Grade 10 biology Cell Biology and Biodiversity – Specimen Collection and Preservation Notes

Specific Learning Outcomes

1. a) Identify apparatus and materials used for collecting, processing and preserving specimens.
2. b) Collect, process and preserve specimens for biological studies using improvised and conventional apparatus (teacher supervised).
3. c) Appreciate the importance of collecting, processing and preserving specimens for research, conservation and education.

Apparatus & Materials (Conventional and Improvised)

Basic safety items for every collection: gloves, safety glasses, hand sanitizer, first-aid kit, teacher supervision and permits when needed.

Step-by-step: Collecting, Processing & Preserving (student-friendly)

1) Plant specimens (leaves, flowers)

1. Record site: date, place (landmark or GPS), habitat (farm, school compound, river bank), collector name.
2. Collect whole leaves/flowers where possible. Avoid damaging rare plants — ask teacher/permit if unsure.
3. Press between newspaper sheets and cardboard; stack several books or use straps. Change papers if damp, and dry in a warm, ventilated place.
4. When dry, glue or tie to a herbarium sheet (A4), label with details and preliminary identification.
5. For long-term DNA or chemical studies, place small tissue in 95% ethanol (teacher supervised).

2) Insects (butterflies, beetles, small arthropods)

1. Use a net or carefully pick into a jar. For observation-only, photograph and release.
2. For preserved specimens: small insects can be humanely killed by placing jars in a freezer (short time) or by using ethyl acetate in a killing jar — only under teacher supervision.
3. Pin larger insects through the thorax on a polystyrene board; store in insect box with labels. For tiny insects use card-pointing or small vials with 70% ethanol.
4. Dry storage must be kept sealed and with naphthalene/other pest controls as directed by teacher to avoid moth damage.

3) Pond water & microscopic life

1. Scoop water with a clean bottle or plankton net. Label bottle with date and site.
2. For immediate observation: place a drop on a slide and examine with a microscope.
3. To preserve plankton: add a few drops of Lugol’s iodine or 4% formalin (teacher supervised). Alternatively, cool and examine within 24 hours.
4. For microbiology (safe school demos only): use sterile swabs and petri dishes — only under teacher supervision and with safe organisms; follow disposal rules.

4) Soil & seed samples

1. Collect in labeled bags. Keep plant seeds dry and store in envelopes with labels.
2. For soil microbes, collect into sterile containers and refrigerate; culture only under supervision.

Labeling & Records (always):

• Date, exact site or GPS, habitat description, collector name, method used, preservative used, field notes and photos.

Common Preservatives & Safety Notes

• 70% ethanol: Good for general preservation (insects, small animals, tissues). Flammable — keep away from flames.
• 95% ethanol: Best for DNA preservation (small tissue samples). Teacher use and secure storage.
• Formalin / 4% formaldehyde (10% formalin): Strong fixative for long-term preservation (museum specimens). Hazardous — teacher only, use gloves, fume hood if possible.
• Lugol’s iodine: Used to fix and stain plankton for microscopy. Stains skin and clothes — teacher supervised.
• Drying / pressing / silica gel: Safe, low-cost methods for plants and flowers.
• Always follow school chemical disposal rules. Never pour strong fixatives into drains; keep chemicals locked away.

Why Collect, Process & Preserve Specimens? (Appreciation)

• Supports identification and study of biodiversity in Kenyan habitats (school compound, farms, wetlands, forests).
• Provides physical evidence for research, comparison and teaching (herbaria, insect collections, museum records).
• Helps monitor environmental change, invasive species and disease — valuable for conservation and local decisions.
• Preserved specimens can be used for future studies (morphology, DNA, education) and for sharing with institutions (e.g., National Museums of Kenya with permission).
• Builds skills: careful observation, recording, safe handling and scientific thinking.

Suggested Learning Experiences (Classroom & Field)

1. Field trip to a nearby habitat (school compound, river/pond, community farm): make a checklist of common plants and insects, collect samples for herbarium and insect box (teacher-supervised).
2. Build an improvised plant press from cardboard and newspaper; each student prepares one herbarium sheet and presents the plant’s features.
3. Pond study: students collect water, observe plankton under microscopes, and prepare one preserved sample using safe amounts of iodine (teacher-led).
4. In-class demonstration on labeling and data recording; each group submits a labeled specimen with a one-page field report (date, location, method, sketch/photo, short description).
5. Compare preservation methods: dry versus ethanol-preserved specimens — discuss advantages and limitations in groups and present findings.
6. Invite a local expert (museum or forestry officer) to speak about permits and ethical collecting in Kenya; link to local conservation issues.
7. Citizen science project: use photos to record species on platforms (e.g., iNaturalist) or compile a “School Biodiversity Map” for the county.

Assessment Ideas & Safety Checklist

Assessment: practical test (collect & prepare herbarium sheet), group field report, quiz on apparatus and preservative choice, short presentation on importance of specimens.

Safety & Ethics Checklist

• Always work with a teacher or supervisor when using chemicals or sharp tools.
• Do not collect protected or endangered species without permit (contact National Museums of Kenya or county offices).
• Wear gloves and eye protection when handling preservatives; label containers clearly.
• Dispose of chemical waste according to school/institution rules. Clean and store equipment after use.
• Respect local communities and private land — ask for permission before collecting on private or protected land.