biological

BIO 103 (General Biology Practical I) Manual

Introduction

• This course focuses on:
  • Common laboratory hazards, prevention, and first aid.
  • Measurements in biology.
  • Care and use of microscopes (both compound and dissecting).
  • Biological drawings and illustrations, including scaling, accuracy, and proportion.
  • Use of common laboratory apparatus for experiments to complement topics covered in BIO 101.

Common Laboratory Hazards, Prevention, and First Aid

• Science labs can be dangerous due to:
  • Glass equipment.
  • Live animals.
  • Chemicals.
  • Water.
• Potential accidents include:
  • Fires.
  • Chemical burns.
  • Slips and falls.
  • Animal bites.
  • Cuts from broken glass.
  • Toxic fume inhalation.
• Importance of first aid knowledge even in well-structured safety environments to treat injuries until professional help is available.

Preventing Lab Accidents

1. Awareness: Know specific hazards related to the task at hand.
2. Preparation Before Work:
   • Inspect equipment for weaknesses (e.g., cracks or chips).
   • Check electrical equipment for fraying.
   • Locate emergency eyewash stations.
   • Ensure first aid kit is fully stocked.
   • Clear up clutter and check for trip hazards.
   • Never work alone in a lab.

Clothing Guidelines

• Wear proper clothing to ensure safety:
  • Long sleeves and long pants or skirts for arm and leg coverage.
  • Closed-toe shoes made of strong materials with flat heels to avoid trips.
  • Long hair should be tied back.
  • Remove jewelry to prevent snagging.
  • Use goggles and gloves when handling chemicals, and a face shield when pouring larger quantities.

Preventing Contamination

• Maintain a contamination-free lab environment:
  • No food or beverages allowed.
  • Remove and properly dispose of gloves after use and wash hands.
  • Carefully handle sharps (needles, syringes) and dispose of them appropriately.
  • Contain materials properly in transport.
  • Always wear clean personal protective equipment (PPE).

Care with Chemicals

• Work in well-ventilated areas; utilize chemical fume hoods.
• Never smell, inhale, or taste chemicals.
• Do not pour chemicals down a drain; know proper disposal methods.
• Ensure all containers are tightly closed and secure when not in use.

First Aid for Lab Accidents

• Bleeding and Wound Care:

  • Minor cuts:
  • Apply pressure with sterile gauze.
  • Clean with soap and water.
  • Cover with a sterile bandage.
  • Serious cuts:
  • Have the person sit down and raise the bleeding aspect while applying pressure.
  • If severe bleeding or fainting occurs, seek immediate medical attention.

• Burns:

  • Heat Burns:
  • Cool the area under running water for 5-10 minutes.
  • For minor burns, apply burn cream and bandage; for serious burns, seek medical help.
  • Chemical Burns:
  • Remove contaminated clothing and rinse with cool running water for 15 minutes; seek medical help.

• Eye Injuries:

  • For chemicals splashing into eyes:
  • Flush with tepid water for at least 15 minutes.
  • Ensure the victim turns their head to allow water to run over both eyes.
  • For solid materials in the eye, cover the eye and seek medical attention.

Microscope

• Definition: An instrument used by biologists and scientists to observe microorganisms and small objects not visible to the naked eye.
• Function: Magnifies objects, creating observable images for the observer.

Microscope Care

• Carry the microscope carefully to avoid dropping it.
• Unplug when not in use.
• Clean the microscope post-use with a dry towel and return it to storage.

Biological Drawings and Illustration

• Purpose: To represent aspects of living organisms visually, aiding in the presentation of biological concepts.
• Guidelines:
  1. Use pencil for all parts of the drawing.
  2. Draw boundary lines free-hand.
  3. Ensure lines are continuous and connect neatly without overlapping.
  4. Maintain single, thin, and firm lines without woolliness.
  5. Avoid shading; use contour lines if needed.
  6. Label all key structures clearly.
  7. Use ruled guidelines.
  8. Label using sentence case, not capital letters.
  9. Include a title beneath the drawing indicating the specimen.
  10. Ensure accuracy by focusing on observed details and proportions.
  11. Draw organisms at the largest possible magnification, occupying 1/3 to 1/2 of the page.
  12. Avoid drawing on both sides of paper.
  13. Include magnification details of the drawing based on microscope use.

Scale and Magnification

• Definition: Represents how much larger or smaller a drawing is compared to the actual specimen.

Magnification Calculation for Specimens

• Non-Microscopic Specimen:
  Magnification = \frac{Length \ of \ Drawing}{Length \ of \ Specimen} \ (cm/mm)
• Microscopic Specimen:
  Magnification = (Magnification \ of \ Eyepiece) \times (Magnification \ of \ Objective \ Lens)

Experiment No. 1: Study of the Cheek Cell

• Title: Exploration of the cheek cell and its organelles.
• Aim: To study the cheek cell and its organelles.
• Materials:
  • Methylene blue solution (0.5% to 1%) diluted with water.
  • Sterile cotton swab.
  • Glass microscope slide, plastic coverslip.
  • Paper towel or tissue.
• Procedure:
  1. Gently scrape the inside of the cheek with a cotton swab.
  2. Smear the swab on the slide and dispose of properly.
  3. Add a drop of methylene blue solution carefully.
  4. Place and adjust coverslip to avoid bubbles.
  5. Focus using x4 objective followed by x10.

Activity

• Draw a labeled diagram of observed squamous epithelial cells and surrounding bacteria.
• Discuss differences between plant and animal cells.

Experiment No. 2: Study of Onion Cells

• Title: Investigation of onion cell structure.
• Aim: To investigate onion cells using wet mount microscopy.
• Materials:
  • Microscope with eyepiece graticule.
  • Microscope slide and cover slip, onion piece, iodine solution.
  • Paper towel, scalpel, white tile, mounted needle.
• Procedure:
  1. Place two drops of water on a slide.
  2. Peel onion membrane and lay flat.
  3. Add iodine solution and cover with coverslip.
  4. Focus using x4 followed by x10 objectives.

Activity

• Draw a group of at least three labeled cells.
• Identify the food vacuole, cell wall, and nucleus.

Risk Assessment