Excessive fertilizer/animal organic waste from agricultural land
/farming area flows into river nearby when it rains
The presence of more minerals/organic substances
Promotes algal growth /growth of aquatic plants
Chapter 9 : Endangered Ecosystem
Green house effects
Ultra violet(uv) from solar radiation is absorbed by the earth
and some of them is reflected back to the atmosphere in the
form of heat/infra red.
Heat or infrared radiation cannot be
Nitrogen fixing bacteria/Rhizobium sp. in the root nodules of
legumes plant/Azotobacter sp/Nostoc
Use nitrogen in the air to make nitrates/carries out nitrogen
Nitrates produced by the bacte
Colonisation and succession in pond
Pioneer : Elodea sp. and Hydrilla sp. (submerged)
Successor 1 : Lemna sp. and Pistia sp. (floating)
Successor 2 : Sedges and cattails (emergent)
Explain how colonization and successio
Explain the process of colonisation and succession in mangrove swamp
The pioneer species of a mangrove swamp are the Sonneratia sp. and Avicennia sp.
The presence of this species gradually changes the physical
Colonisation and succession in an ecosystem
A group of organisms that look alike and capable
of interbreeding and producing fertile offspring
The natural environment in which organism can
get food, shelter, living space, nesting an
Chapter 8 : Dynamic Ecosystem
Sequence of organism which energy is transferred/flow
from trophic level to another trophic level by eating
In food chain, the energy received by the organism in each trophic level is only 10%
from the pre
Describe how the change of oxygen and carbon dioxide content are
regulated by the body
F1 The higher level of carbon dioxide in the blood cause the drop of
the pH value
F2 The drop in pH is detected by central chemoreceptor in medulla
Breathing mechanisms in man
Diaphragm is a muscular sheet in the body cavity separating the thorax from the abdomen.
At the start of inhalation, the muscles of the diaphragm contract , making it less arched.
The adaptation of respiratory structure of amphibians(frog)
Anaerobic respiration in human muscle
During a vigorous exercise (running), the breathing rate is increased.
This is to supply more oxygen to the muscles for rapid muscular contracti
Respiratory structures and breathing mechanism in human and animals
Respiratory structue is the organ for respiration
Respiratiry surface is the site where the exchange of gases occur
Chapter 7 : Respiration
Respiration is the process of oxidation of complex
organic substances with the release of energy utilizes
oxygen an dremoving carbon dioxide in living cells
There are two types of respiration
Aerobic respiration (presence of oxygen
Explain the diet for the following people
A lady athlete:
An athlete is a very active person and has high rate of metabolism to produce energy.
The diet should include more carbohydrates to supply enough energy to carry out the vigorous
The formation of starch in plants is by the process ofphotosynthesis which occurs in chloroplasts.
The two stages in photosynthesis are the light and dark reactions.
takes place in
Assimilation of digested food
In the Liver
F1 Amino acids is needed to synthesis new plasma protein
F2 When a short supply of glucose and glycogen occurs, the liver
converts amino acids into glucose
F3 Excess amino acid cannot be stored, so amino acids is
Explain three structural adaptation of intestinal for effective absorption of food
- When the question asked for
adaptation, your answer must be in the
form of STRUCTURE + FUNCTION
- When the question asked for function,
start your answer
Digestion in Rodent and Ruminant (essay)
Digestion of cellulose by ruminant
Partially chewed food is passed to the rumen (largest compartment of the stomach).
Cellulose is broken down by cel
Summary of the digestion
Ileum (small intestine)
Have intestinal gland which secrete intestinal juice
that contain enzymes :
Have salivary gland to secrete saliva
Saliva contain salivary amylase
Salivary amylase will digest
Maltose + water
Examples of essays
Digestion in mouth
Secretion of saliva by three pairs of
Saliva contains the enzyme salivary
Begins the hydrolysis of starch to maltose.
Starch + water
An additional digestive process occ
Chapter 6 : Nutrition
Energy value of food (kJ g-1)
Percentage of vitamin C in fruit juice =
Test on food samples
Concentration of vitamin C in fruit juice =
Exam tips :
- Process in Meiosis II is likely same as
- The term use for Meiosis I is
Homologous chromosome while in
Meiosis II, the term used is sister
Similarities between Meiosis I and Meiosis II
Both consist of four stages
Synapsis, Crossing Over and Chiasmata(singular : chiasma)
Synapsis is the process where
the chromosomes pairing up
Crossing over is the process
where non sister chromatids
exchange segment of genetic
Chiasmata is the point where
Small pieces of
tissue is cut (e.g :
Plant cell divide by
mitosis to form callus
mass of tissue
1. During prophase I, homologous
chromosomes pair up (synapsis) and
crossing over betwe
Application of Mitosis
Advantages of cloning
Biotechnologists to multiply copies of
useful genes or clones.
Clones can be produced in a shorter time
and in large numbers.
Cloned plants, however, can produced
flowers and fruits w
Cytokinesis in animal cell
Process of cytoplasmic division.
Begins before nuclear division is completed.
Actin filament formed contractile ring.
Contracts and constrict pull aring of plasma membrane inwards.
Groove of cleavage furrow pinch
Stages in mitosis
Pro Meta Ana Telo
Chromosomes in the
shorter and thicker.
Consist of sister
chromatid joined at the
Spindle fibres begin to
Centrioles migrate at
At the end,
Chapter 5 : Cell Division
Where do mitosis occur?
In plants, mitosis occur in meristematic tissues.
What is meristematic tissues?
All parts of the body except TESTES and OVARY
What is monosaccharides?
Exam tips :
Glucose + monosaccharides
Exam tips :
Addition of water is
necessary. Must be
What is disaccharides?
Glucose + glucose
Glucose + fructose
Glucose + galactose