Saturday, October 13, 2007
O level time table18 Oct 2007 - Science Practical22 Oct 2007 - A maths Paper 1 ( 14 30 to 16 30)23 Oct 2007 - A maths Paper 2( 14 30 to 16 30)24 Oct 2007 - Science Paper 3(Chem) (14 30 to 15 45)25 Oct 2007 - Combined humanites Paper 2(Geo) ( 1430 to 16 00)29 Oct 2007 - English Paper 1 ( 08 00 tp 09 45)29 Oct 2007 - English Paper 2 (10 15 to 11 55 )29 Oct 2007 - E maths Paper 1 ( 14 00 to 16 00)30 Oct 2007 - E maths Paper 2 ( 08 00 to 10 30 )31 Oct 2007 - Chinese Paper 1( 08 00 to 10 00)31 Oct 2007 - Chinese Paper 2 ( 10 30 to 12 00)02 Nov 2007 - Science Paper 2 ( Phy) (08 00 to 09 15 )05 Nov 2007 - Combined humanities Paper 1(ss)( 08 00 to 09 30 )05 Nov 2007 - Biology Paper 2 ( 14 00 to 15 45)06 Nov 2007 - Science Paper 1 ( 08 00 to 09 00 )13 Nov 2007 - Biology Paper 1 ( 09 30 to 10 30 )mgh :)
11:30 AM
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Saturday, June 09, 2007
Holiday Homework
- E Maths : Complete Casco 'O' level mathematics
- A maths : A Maths textbook Revision Ex1 (pg 111), Ex2 (pg219) & Ex3(pg367)
- English : Comprehension & Standard vs Non-standard English wkst
- Chemistry : can be found in http://sharepoint.peicaisec.moe.edu.sg/
- Physic : workbook pg 119 to 123 & pg 127 to 131
- Bio : TYS pg 161 Qn 2 and 4 ,pg 162 Qn 5 & discussion on the movie, The Island (can be found in the sharepoint website but must wait till miss toh upload it)
- Social Studies :Structure Essays Question on Venice(Note: email your work to mrs kalai one week before sch reopen)
- Mother Tongue : Practise your oral!!
Start doing now!!=)
MGH=))
1:31 AM
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Friday, June 08, 2007
DATES FOR MOCK EXAMS
19June07 Tuesday
0800-1000: Emaths Paper1
1045-1315 : Emaths Paper2
20June07 Wednesday
English
21June07 Thursday
0800-1000: Amaths Paper1
1045-1245 : Amaths Paper2
( venue: classroom )
REMEMBER TO TURN UP!!!!!!! MGH=))
11:50 PM
& SHINE LIKE A STARR.
Wednesday, May 30, 2007
Hi 4G
Look like I can't post my notes here. I will find another way for you to access the notes. Find out more on Friday. Don't be absent ok !!!!!!
Bye !!!
Mdm Faridah
Your Sc(Chem) teacher for 2 long...... years
4:30 AM
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Friday, May 25, 2007
Remember to turn up for your oral prelim exam on 29/5 (Tuesday).
Schedule is as follow, in case you dun know:
0800 - 1045:
Register nos. 1-3 (2B classroom), 4-16 (2F classroom), 30-35 (2C classroom)
1115 to 1400:
Register nos. 17-29 (2F classroom)
DO NOT BE LATE
BE IN PROPER ATTIRE
NO HANDPHONES IN POSSESSION (POCKETS/BAGS) THROUGHOUT EXAM (even while waiting in the classroom)
GOOD LUCK TO ALL - Ms Toh
1:25 PM
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Wednesday, May 09, 2007
Here're the solutions to the questions you were all suppose to practice for BIO TYS.
Do also read ALL the notes I'd previously printed for you. They'll be helpful.
During the BIO exam, you MUST read the questions carefully, KNOW WHAT IT WANTS, check the marks to be awarded... and USE YOUR INTELLIGENCE.
Study hard. Good luck to you :)
Ms Toh
1:31 PM
& SHINE LIKE A STARR.
PURE BIOLOGY TYS
RECOMMENDED ANSWERS TO SELECTED QUESTIONSTOPIC 12: Coordination and Response
P101, Q55(a) Position 4
5(b)
- Circular muscles in the iris relax;
- Radial muscles in iris contract.
- This antagonistic action of the two sets of muscles
- causes pupil size to increase thus allowing more light to enter eye.
5(c)(i) Pupil reflex
5(c)(ii)
- Prevents excessive light from entering eye.
- Prolong exposure to excessive light can damage light sensitive region (retina) of eye.
P102, Q1616(a)
- When hand touches hot object, heat stimulates nerve endings (receptors)
- in the skin (sense organ).
- Impulses produced travel along sensory/receptor neurone
- to the spinal cord.
- In the spinal cord, impulses are transmitted first across a synapse
- to the intermediate/relay neurone
- and then across another synapse
- to the motor/effector neurone.
- Effector neurone transmits the impulse to the effector
- The effector, which is the biceps muscles then contracts and withdraws the hand.
16(b)
- Events described in (a) is involuntary and
- involves a reflex arc (receptor, sensory neurone, relay neurone, reflex centre, motor neurone and effector)
- A deliberate action is voluntary and
- does not involve a sensory neurone as it is controlled by the will.
TOPIC 15: Food Chains, Food Webs and Carbon CycleP121, Q1212(b)(i)
- Radiant energy captured by producers through photosynthesis.
- Primary consumers get energy from producers when they feed on plants.
- Energy is passed from one trophic level to the next through feeding.
- Flow of energy is non-cyclic.
12(b)(ii)
- Energy consumed at each level is lost through respiration, excretion, egested material, movement etc.
- Dead organisms and excretory materials contain trapped energy
- which are released to environment by activity of decomposers
- or through combustion of fossil fuels.
12(c)
- 90% of the energy in crop plants will be lost to the environment if fed to the animals.
- That means the animal only retains and passes on 10% of the energy consumed to the next trophic level, i.e. human consumption.
P121, Q1515(a) Ecosystem
15(b)(i) Organisms H and J
15(b)(ii)
Energy used: RADIANT/LIGHT ENERGY
Energy passed on: CHEMICAL ENERGY
15(c)(ii)
Increasing concentration as it goes higher up the food chain.
Insecticide accumulates in bodies of organisms and builds up in the top predators.
15(d) Insecticides used on the plants/crops near the lake had seeped into the soil. It then dissolves in the water and get washed out into the lake
TOPIC 17: Effect of Man On The EcosystemP127, Q11(a)(i) 4th Month
1(a)(ii)
Insect A: 18 months
Insect B: 14 months
1(b)
- Over time, effect of insecticide is gone and thus unable to control population.
- Insects reproduce over the few months to increase the population size.
- Natural predator and prey relationship sets in to return the biological equilibrium/balance.
1(c)(i) Insect B is the carnivore
1(c)(ii)
- Population of Insect B is lower than A.
- This is characteristic of most predator and prey relationship whereby predators are smaller in numbers than prey.
- Population of insect B is reactive towards the drop of insect A numbers, i.e. Insect A population started declining at month 15 before insect B population reacted to the reduction in food supply (insect B) one month later.
P127, Q22(a) At about 10km downstream
2(b)(i)
- Bacteria grow and multiply rapidly, explaining the increasing bacteria population from 10km to 20km.
- The high BOD of bacteria causes the depletion of oxygen in the water, hence the drop in concentration of dissolved oxygen between 10kmto 20km.
- Following the drop in oxygen supply in the water, organisms like fishes die
2(b)(ii) untreated sewage discharged into the river.
2(c)
- A large part of the fish population had died upstream where the pollution was very serious. There are not many mature fish left and it would take time before they can reproduce and return the population to its original level.
- Although oxygen level is returning to original level, it is still relatively low and not as viable to support a big population of organisms.
TOPIC 18: Sexual and Asexual Reproduction in PlantsP136, Q11(b)(i) Wind
1(b)(ii)
- small petals
- large feathery stigma
- long pendulous filament
- numerous, small pollen grain (DO NOT use light because we can’t tell the weight by looking at the figure)
P136, Q22(a) Starch. It has been used up completely used up at the stage of a seed. The other constituents remain present in the seed and are not fully utilized.
2(b)(i) Cellulose
2(b)(ii) Remains relatively constant, only a slight increase is observed. Increase is due to increasing mass of a growing seedling which develops more cells.
2(c) As the seedling grows, it develops leaves to carry our photosynthesis. Glucose produced in photosynthesis is stored as starch.
P138, Q99(a)
A: Radicle
B: Cotyledon
C: Testa
9(b) Germination
9(c)(i) Absorbs water
9(c)(ii) Enzymes break down starch into simpler substance
9(c)(iii) Photosynthesis is carried at stage 4
9(d) Sugar stored in cotyledon has been used up. Glucose present in plant is now converted into starch for storage.
P139, Q17
17(a)
- The long pendulous filaments (B)
- protrude out of the bracts,
- exposing the mature anthers (C) to the wind.
- The delicate filament sway in the slightest breeze.
- The dust-like pollen is shaken free and carried away by the wind.
- The large, feathery stigma (A)
- also project out of the bracts,
- providing a large surface area to receive the pollen that may be floating around.
17(b)(i)
- do not need external agencies for pollination or dispersal
- desirable qualities are passed on without any change
- only requires one parent
- can colonise a habitat more rapidly
17(b)(ii)
- Can produce crops with better quality and higher yield
- Crops mature faster and as they are not grown from seeds
P140, Q22
22(a)
- avoid overcrowding and competition for food
- enable plant to colonise new and favourable habitats
- reduce spread of diseases
22(b)(i) Seed
22(b)(ii) Ovary wall
22(c)
Fruit W:
Method of dispersal: By wind
Explanation:
- Parachute of fine hair
- increases surface area/ air resistance/ buoyancy in air
Fruit X:
Method of dispersal: By animals
Explanation:
- Hook-like structure
- attaches to animals’ fur
22(d)
- No/insufficient water
- Unsuitable temperature
- Inadequate oxygen supply
P141, Q2323(a)
P: Sperm
Organ: Testis
Q: Pollen
Organ: Anther
23(b)
R is a flagellum that enables the sperm to swim/ propel from vagina to the fallopian tube towards the egg.
S is a pollen tube that penetrates through the style and carries the male gamete towards the ovary/ovule
23(c)
Similarities: Contains chromosomes/genetic material
Differences: Structure T has a haploid number of 23 chromosomes. Contains only half the chromosomes of the cells which produced it
TOPIC 19: Sexual Reproduction in Man & Sexually Transmitted DiseasesP149, Q14
14(a)
A: placenta
B: amniotic sac / amnion (Amiotic fluid is wrong)
C: urinary bladder
D: vagina
14(b)
- supports/cushions embryo
- shock absorber/ prevents mechanical injury
- lubricates/ reduces friction in vagina during birth
- bouys up foetus and allows it to move freely during growth
14(c)(i) carbon dioxide, urea (Metabolic waste is NOT accepted)
14(c)(ii) artery
14(d)(i) absence of Y chromosomes in the nucleus OR presence of 2 X-chromosomes in the nucleus
14(d)(ii) Presence of an extra chromosome 21
P149, Q15 ** draw a simple biological diagram of the female reproductive system (front view) and label the parts identified in the answer
15(a)
Two ovaries where eggs mature and are released, one every month and where female hormones (oestrogen and progesterone) are produced
Fallopian tube or Oviducts is the site of fertilization.
Muscular tube that carries unfertilized egg or zygote towards the uterus
Uterus is where baby/fetus develops during pregnancy
Uterine wall/lining provides nutrients to developing fetus and is shed every month during menstruation if woman is not pregnant.
Cervix is the narrow opening at the lower end of the uterus
Vagina is the birth canal and also where semen is deposited during intercourse
15(b)(i)
Syphilis
Signs/Symptoms:
- rashes or sores on genitals, mouth and throat
- bald patches may appear on head
- heart failure
- blindness
- damage to brain and spinal cord leading to paralysis and death
15(b)(ii)
Control spread:
- treat infection with antibiotics promptly
- infected persons refrain from intercourse
- use condoms during intercourse
- keeping to one sex partner
P150, Q1717(a)(i) Egg/Ovum which is a haploid cell (DO NOT write ‘Egg, Haploid’… seems like examiner must choose the right answer)
17(a)(ii) Fertilisation
17(a)(iii) Zygote which is a diploid cell
17(b) Zygote will splits into two cells, each grows independently into a baby
17(c)(i) One egg is fertilized by a sperm containing 2 X-chromosomes. This zygote then divides into two cells which develop into a pair of identical baby girls.
17(c)(ii) Two eggs are released at about the same time. One if fertilized by a sperm carrying the Y-chromosome. The other by a sperm with 2 X-chromosomes. The zygote with Y chromosome develops into a male, while the other develops into a female.
1:02 PM
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Friday, January 26, 2007
Homework:Amath-
Ex12C pg 266 Qns 8, 12, 14, 16 [Monday290107]Test:Amath test on Functions.
[Monday 290107]Chinese spelling chapter 1 & 2.
[Words can be found in bi ji. Monday 290107]Amath test on Limits & Differentiations.
[Tuesday 300107]Chem test on periodic table.
[Tuesday 300107]Things to bring:English exercise book used in Sec3.
[Monday 290107]Other than that, those people whom MsLee wrote "redo" on their papers, remember to redo. Monday's the deadline. Happy weekends then! Gnights!June
9:32 PM
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