CHAPTER 1 : INTRODUCTION TO BIOLOGY AND LABORATORY RULES

1.2 SAFETY AND RULES IN BIOLOGY LABORATORY

Laboratory Protective Equipment
Emergency Shower  Used when chemicals/hazardous substances come into contact with skin
Eye Wash Station  Used to wash the eyes when exposed to chemical/hazardous subtances
Fume Hood  To avoid breathing in hazardous gases : chlorine, bromine and nitrogen dioxide
Laminar Flow Cabinet  Provides flow of filtered air for clean work area in laminar flow cabinet
Biological Safety Cabinet  Provides an enclosed work space to study materials that have been
Biological Safety Cabinet  contaminated by pathogens

Personal Protective Equipment

Goggles, Face mask, Laboratory gloves, Handwash, Lab coat, Lab shoes

Substances that can be disposed into the sink

- Chemicals with pH values 5-9
- Low concentration liquids and solutions that are harmless to users : sucrose solution

Substances that cannot be disposed into the sink

- Organic solvents (acetone, alcohol, benzene)
- Substance that have a pH value less than 5 or more than 9
- Chemicals (acids, greases, oils)
- Solid waste (chemicals, glass, rubber)
- Heavy metals (mercury)
- Volatile substance
- Toxic substance
- Organic waste (microorganisms, carcases)
- Reactive substances
- Radioactive substances

Methods for managing biological waste

Biological waste categories Management method

Category A (sharp wastes) Placed into a special bin for sharp material disposal
The bin does not need to be sterilised
Category B (non-sharp wastes) Packed first in autoclave resistant biohazard plastic bags
Sterilised in an autoclave for decontamination
Placed into a biohazard bin
Category C (animal carcasses) Wrapped carefully in absorbent material (tissue paper)
Packed carefully into a biohazard plastic bag and frozen
Category D (liquids) Decontaminate by autoclaving before disposal
 OBJECTIVE

1. Decontamination by autoclaving is done a temperature of 121°C and pressurised

at 15 psi for 20 minutes.
2. Biohazard plastic bags that have been sterilised in an autoclave and sharp waste
bin must be stored temporarily in a controlled storage place until the scheduled
time for disposal

Accidents in the laboratory

Steps to Handle General Chemical Spills Steps to Handle Mercury Spills

1. Inform teacher 1. Inform teacher
2. Declare spill area as restricted zone 2. Declare spill area as restricted zone
3. Prevent spreading using sand 3. Sprinkle sulphur to cover the mercury
4. Scoop up chemical spill using spills
appropriate equipment 4. Call the fire and rescue department
5. Dispose it safely

Practices in the laboratory

Laboratory Safety Rules Safety Measures for Fires

1. Don’t work alone without supervision 1. Stop work immediately
2. Wash hands after experiment 2. Switch off all nearby power sources
3. No irrelevant items in laboratory 3. Unplug appliances
4. Clean workstation using disinfectant 4. Exit the laboratory according to
5. Dispose wastes according to the set emergency exit plan
procedures 5. Call the fire and rescue department
6. Do not eat and drink in the laboratory 6. Do not panic and stay calm
7. Identify all safety symbols on 7. Do not turn back to collect belongings
substances and equipment before use 8. Assemble at the assembly point
Handling Glass and Chemicals Handling Live Specimens
1. Be cautious when handling hot 1. Use appropriate gloves when handling
glassware biological specimens
2. Report any damaged equipment or 2. Specimens that are not harmful and
glassware to teachers immediately have been dissected 解剖 should be
3. Keep flammable chemicals away from buried or frozen
fire sources 3. Wash hands with antiseptic
4. Do not touch, taste and smell detergents before and after
chemicals directly experiment
4. Clean surface and workstations with
disinfectant before leaving the lab
Emergency Help
1. Inform teacher
2. Call the fire and rescue emergency number
3. Remove the victim from the scene
4. Give emergency treatment
5. Make the place of accident as a restricted area

Scientific Attitudes and Noble Values

1. Having interest and curiosity
2. Being honest and accurate in recording and validating data
3. Being diligent and persevering
4. Being responsible
5. Appreciating and practising clean and healthy living
6. Appreciate the contributions of science and technology
7. Think critically and analytically

1.3 COMMUNICATING IN BIOLOGY

(a) Table
(b) Graph
(c) Biological Drawing

Characteristics of Biological Drawing

1. Large and accurate ; use a sharp pencil and not a colour pencil or pen
2. Not shaded artistically
3. Lines drawn must be clear, clean and continuous.
4. Do not use ruler to draw the outline of a specimen
5. Drawings must be labelled
6. Label lines must point to the correct structure, no arrowheads, must be straight and not
6. crossing each other
7. Drawings must have titles
8. Structure in drawing must be placed in correct position, size should be proportionate to the
8. rest of the structures
9. Magnification factor of a drawing must be stated

Plan Drawing  Line drawing that shows the outline of a structure

Detailed Drawing  Shows the cells in a structure
Planes
Sagittal plane (Divides the body into right and left parts)
Frontal plane (Divides the body into frontal and rear parts)
Horizontal plane (Divides the body into upper and lower parts)

Section
Cross section (Divides the structure into upper and lower portions horizontally
Longitudinal section (Divides the structure into left and right portions)

Directions
Superior (The part that is above all other parts to towards the head)
Lateral (Far from the midline or at the side of the body)
Inferior (Situated below other parts or towards the feet)
Ventral (Towards the lower part of the body)
Dorsal (Towards the upper part of the body)
Anterior (Towards the front of the body)
Posterior (Towards the back of the body)

1.4 SCIENTIFIC INVESTIGATION IN BIOLOGY

1. Identifying problems
2. Forming a hypothesis
3. Identifying and controlling variables and data collection method
4. Planning and carrying out a scientific investigation
5. Collecting data
6. Interpreting data and results through scientific reasoning
7. Forming a conclusion
8. Writing a report
CHAPTER 2 : CELL STRUCTURE AND FUNCTION

OBJECTIVE

1. Using a mounting needle, cover the onion epidermis with a cover slip by placing it
at a 45° angle to the slide and slowly press it down. The temporary slide of this
specimen is named as wet mount.
2. Add a drop of iodine solution on one side of the cover slip. Place the filter paper
at the opposite end of the cover slip to draw the iodine solution to absorb and
stain the entire onion epidermis. This technique is known as the irrigation
technique.
CHAPTER 3 : MOVEMENT OF SUBSTANCES ACROSS PLASMA MEMBRANE

3.1 Structure of Plasma Membrane

1. Fluid Mosaic Model (Draw)
- Fluid refers to phospholipid bilayer and protein molecules float freely and are free to move
- sideways within the membrane
- Mosaic beause it has various protein molecules embedded in the phospholipid bilayer

2. A phospholipid molecule has:

- A polar head which is hydrophilic
- A nonpolar tail which is hydrophobic

3. Other molecules present in plasma membrane:

(a) Cholesterol
- Stronger, more flexible, less permeable to water-soluble substance (ions)
(b) Carrier protein and channel protein (pore protein)
(c) Glycolipid
(d) Glycoprotein

4. Function of glycolipid and glycoprotein (SAR)

(a) To stabilise the plasma membrane by forming hydrogen bond with the water
(b) Act as antigens for cell identification
(c) Act as receptors for hormones such as insulin

3.2 Concept of Movement of Substances Across a Plasma Membrane

Characteristics Substances Through Process

- Lipid-soluble - Vitamin A, D, E, K Phospholipid Simple diffusion,
substances - Fatty acids bilayer Osmosis
- Small, non-polar - Glycerol
molecules - Water
- Small, polar - Oxygen
molecules - Carbon dioxide

- Ions - Potassium Channel Facilitated diffusion,

- Polar molecules - Calcium protein Osmosis
- Sodium
- Water
- Large, water- - Glucose Carrier protein Faciliated diffusion,
soluble polar - Amino acids Active transport
molecules - Potassium
- Small, water- - Calcium
soluble ions - Sodium
Passive Transport
Passive transport is the movement of substances across the plasma membrane from a region of
high concentration to a region of low concentration

Simple Diffusion
Movement of substances across the plasma membrane from a region of high concentration to a
region of low concentration until dynamic equilibrium is achieved

Example : Gaseous exchange between body cell and blood capillaries

Osmosis
Net movement of water molecules from a region of high water potential to a region of low
water potential through a selectively permeable membrane

Example : Absorption of water by root hair cells of a plant

Facillitated Diffusion
- Involves both carrier protein and channel protein
- Mechanism of carrier protein in facillitated diffusion:
(a) Solute move to the binding site of the specific carrier protein
(b) Solute binds to the binding site of the carrier protein, triggering the carrier protein to change

its shape
(c) Carrier protein changes its shape and the solute moves across the plasma membrane
(d) The carrier protein returns to its original shape

Example : Absorption of fructose molecule in the villus

Active Transport
Active transport is the movement of substances across the plasma membrane from a region of
low concentration to a region of high concentration with the use of energy

Mechanism of sodium-potassium pump:

(a) Three sodium ions from inside of the cell binds to the carrier protein
(b) The ATP decomposes into ADP and P. The phosphate group is bound to the carrier protein
(c) Phosphate bond provides energy, the carrier protein changes shape, three sodium ions is
transported through the carrier protein out of the cell
(d) Two potassium ion from outside of the cell binds to the carrier protein
(e) The phosphate group leaves the carrier protein. Carrier protein restores its original shape
(f) Two potassium ion is transported across the carrier protein into the cell
Proton pumps
- Found in the epithelial cells lining the stomach cavity
- In response to eating, the epithelial cells lining the stomach cavity uses ATP to pump large
- number of hydrogen ions into the stomach
- This causes an accumulation of hydrogen ion and acid production in the stomach cavity

Example : Absorption of glucose and amino acids in the villus

Isotonic, Hypotonic and Hypertonic solutions

Water will diffuse from a hypotonic solution to a hypertonic solution by osmosis.
Hypotonic : Low solute concentration, high water potential
Hypertonic : High solute concentration, low water potential

Effect of hypotonic, hypertonic and isotonic solutions on animal cells and plants cells

Situation Result
Plant cell is immersed in a hypotonic solution Turgid
- Do not burst due to rigid cell wall
Plant cell is immersed in a hypertonic solution Plasmolysed (Process : Plasmolysis)
- vacuole and cytoplasm will shrink causing
plasma membrane being pulled away from
the cell wall
Plant cell is immersed in an isotonic solution Flaccid

Situation Result
Animal cell is immersed in a hypotonic Haemolysed (Process : Haemolysis)
solution - RBC swell and finally burst @ no cell wall
Animal cell is immersed in a hypertonic Crenated (Process : Crenation)
solution - RBC shrink
Animal cell is immersed in an isotonic solution Maintain its biconcave shape
CHAPTER 4 : CHEMICAL COMPOSITION IN A CELL

OBJECTIVE

1. Chitin, a type of polysaccharide, is used as a surgical thread. The advantage is that

chitin will decompose after the sewn wound heals.

CHAPTER 9 : NUTRITION AND THE HUMAN DIGESTIVE SYSTEM

OBJECTIVE

1. Liver cirrhosis is a type of liver disease caused by factors such as alcoholic drinks,
toxic substances and hepatitis. Liver cells are replaced by scarred cells that can
cause failure in the liver functions.
2. Hepatitis is an inflammation of the liver caused by viral infection, toxic substances
or autoimmune reaction.

CHAPTER 10 : TRANSPORT IN HUMANS AND ANIMALS

OBJECTIVE

1. Perfluorocarbon (PFC) emulsions can be potentially used as artifical blood. Studies

have shown that PFC has the capacity like blood to transport oxygen and carbon
dioxide

CHAPTER 11 : IMMUNITY IN HUMANS

OBJECTIVE

1. Perfluorocarbon (PFC) emulsions can be potentially used as artifical blood.

Studies have shown that PFC has the capacity like blood to transport oxygen and
carbon dioxide
2. Ministry of Health (MOH) recommends that babies aged 2 to 3 months be
immunised against diseases such as diphtheria, pertussis, tetanus, poliomyelitis
and meningitis.
3. HIV is able to mutate and change the cell structure when it spreads. This gives
the virus a high resistance to drug therapy.
CHAPTER 12 : COORDINATION AND RESPONSE IN HUMANS

OBJECTIVE

1. All receptors can be considered as energy converters, that is, receptors can
convert one form of energy into another. For example, the eye photoreceptor
converts light energy into electrical signals, which is a form accepted by the
nervous system.
2. The cobra’s poision can cause paralysis by preventing the action of
neurotransmitter.
3.

CHAPTER 13 : HOMEOSTASIS AND THE HUMAN URINARY SYSTEM

OBJECTIVE

1. Body temperature is regulated by the integumentary system, nervous system,

circulatory system, muscle system and endocrine system
2. Blood sugar levels are regulated by the endocrine gland, circulatory system and
digestive system
3. The partial pressure of carbon dioxide in the blood is regulated by the respiratory
system, circulatory system and nervous system
4. Blood pressure is regulated by the circulatory system and nervous system

CHAPTER 15 : SEXUAL REPRODUCTION, DEVELOPMENT AND GROWTH IN HUMANS AND

ANIMALS

OBJECTIVE

1. One of the side effect of low oestrogen is calcium loss in the body which leads to a
reduction in bone density, making it porous and weak. This condition is called
osteoporosis.
CHAPTER 2 : LEAF STRUCTURE AND FUNCTION

OBJECTIVE

1. Cacti in the desert on their stomata only during the night for carbon dioxide.
Colder temperature at night can reduce the loss of weight.
2. Limiting factor is a factor that controls a biochemistry process and changes
according to other variables. An increase in the limiting factor will increase the
rate of certain biochemistry process if the other factors are constant.

CHAPTER 5 : RESPONSE IN PLANTS

OBJECTIVE

1. Uneven auxin distribution in tendrils allow tendrils to coil or wrap around an

object. This response is known as thigmotropism.
2. Avoid using plastic bags to trapp ethylene as trapped moisture could lead to faster
fruit spoilage

CHAPTER 6 : SEXUAL REPRODUCTION IN PLANTS

OBJECTIVE

1. Starch obtained from grains such as wheat, rice, barley and corn is the endosperm
tissue formed from double fertilisation

CHAPTER 7 : ADAPTATIONS OF PLANTS IN DIFFERENT HABITATS

OBJECTIVE

1. Plants in the Arctic are also classified as xerophytes. This is because the plants in
the Arctic cannot absorb water when the ground is frozen.