BIO Paper 1 SPM answers

Suggested answers for those have tried attempted this paper:

REVIEW OF THE 2009 SPM BIOLOGY PAPER 1


1. P is mitochondrion, Q is Rough endoplasmic reticulum, R is chromosome
Answer : C
2. Organelle that synthesizes protein is ribosome
Answer: B
3. P shown in the structure of plasma membrane is a carrier protein.
Answer: D
4. After one hour, there will be a rise in capillary tube because the water molecules from distilled water which is hypotonic has entered the Visking tubing via osmosis.
Answer: C
5. The process X is osmosis because water molecules from distilled water will diffuse through the egg membrane which is a semi permeable membrane.
Answer: A
6. The type of movement of molecules P is facilitated diffusion because it moves along concentration gradient
Answer: D
7. The correct sequence of the production of the extracellular enzyme is R Q P
Answer: C
8. The Diagram which shows the cell has been immersed in a hypotonic solution is the one which shows the largest vacuole.
Answer: C
9. The process of formation of a disaccharide molecule from two monosaccharide is known as condensation.
Answer: B
10. Hydrolysis of protein is represented by the equation D
Answer: D
11. Diagram which shows cell that is produced by the cell division of mitosis is A
Answer: B
12. The stage of the mitotic cell division is metaphase because the chromosomes are aligned at the equatorial plane.
Answer: D
13. The individuals of P is breast feeding mother, Q is construction worker and R is a clerk. This is because a bar chart shows the highest energy requirement for Q, the second highest for P and the least for R
Answer: B
14. The food in Level 1 in a food guide pyramid for a balanced diet is rice which is a carbohydrate.
Answer: B
15. The most suitable menu for those suffering from night blindness are Q,S and T which includes vitamin A
Answer: A
16. The cells in a leaf which transport organic substances and water are N and M which are phloem and xylem respectively.
Answer: C
17. The process shown in a Diagram is assimilation where glucose and amino acid are transported to the body cell.
Answer: A
18.The labeled part which contains beneficial bacteria is colon.
Answer: D
19. The purpose of plucking the leaves from a seedling before transferring it from the nursery to the orchard is to reduce the rate of transpiration.
Answer: C
20. The rate of heart beat after the boy stops running is indicated by part B because the heart beat is back to the normal.
Answer: B
21. Based on Diagram given, the adaptations of alveolus which increase the rate of gaseous exchange include: located close to blood capillaries and covered by a thin film of moisture
Answer: D
22. The processes which occur in the respiratory system of a mountain climber which has dropped from its normal level so that the level is returned to normal are: breathing and ventilation rate increase and respiratory muscles contract and relax faster.
Answer: C
23. The total amount of energy used by the plant is when it is absorbed by plant, and for growth.
Answer: C
24. An equation for an anerobic respiration is P is Glucose, Q is oxygen, R is carbon dioxide, S is water and T is ATP.
Answer: D
25. The immediate effect of smoking on the respiratory surface is dries up the lining of alveoli
Answer: B
26. The correct sequence about a sampling technique to estimate the population size of garden snails in a habitat is capture a large number of garden snails and mark each shell, release the garden snails in the same habitat, capture at random a number of garden snails and record the number which are marked and calculate the population of the garden snails
Answer: A
27. The abiotic components in an ecosystem are humidity and light intensity
Answer: C
28. The correct sequence refers to the thinning of the ozone layer is : CFC leaks out of air conditioner, Ultra violet rays break down CFC molecules, then chlorine atom breaks down ozone molecule.
Answer: D
29. The environmental phenomenon which show the melting of ice at the poles and an increase in sea level is global warming.
Answer: D
30. The procedure to investigate the level of water pollution in a river is:
Fill the reagent bottles with water samples, use a syringe to add 1 ml of methylene blue solution, place the reagent bottles inside a cupboard, then record the time taken for the methylene blue solution to decolorize.
Answer: A
31. B.O.D. value is high in river X shows that the river is polluted.
Answer: A
32. The labeled vascular tissue in a tree trunk is sieve tube.
Answer: B
33. The formation of oxyhaemoglobin takes place in the lungs and the dissociation of it occurs in body cells.
Answer: A
34. The part in the gills of a fish which has the highest rate of gaseous exchange is the lamellae
Answer: C
35. The systemic circulatory system is when the oxygenated blood flows from left ventricle to the body, then deoxygenated blood flows from body to the right atrium.
Answer: C
36. A complete ring of bark is removed from a stem of a woody plant. After a few months, the leaves start to fall off and finally the plant dies. This is because sugar is not transported to the roots.
Answer: B
37. The curve which shows the concentration of the antibody after the 8th week of an individual who was affected with measles is B
Answer: B
38. Substance which is injected into the body to stimulate the production of antibodies is vaccine
Answer: B
39. Bones that make up the pectoral girdle are clavicle and scapula.
Answer: D
40. Substances which moves across synapse is neurotransmitter
Answer: D
41. Structure which carries the impulses towards the spinal cord is afferent neurone
Answer: A
42. Based on graph showing changes in the blood glucose level, the true statement is hormone X which is insulin lower the blood glucose level
Answer: A
43. Part of the brain which controls the breathing process is medula oblongata
Answer: D
44. The formation of female gametes is known as oogenesis
Answer: B
45. In spermatogenesis, the groups of cells which have a haploid number of chromosome is secondary spermatocyte and spermatids.
Answer: D
46. In the development of a follicle in an ovary, the structure which involve in secreting progesterone is corpus luteum.
Answer: C
47. A wife has difficulty in ovulating. The hormone treatment which is the most suitable to help the wife to ovulate is Luteinizing hormone.
Answer: B
48. A boy has blood group A and his sister has blood group B. The correct combination of genotypes belonging to their parents are father: AB, mother: AB
Answer: A
49. After 15 days the Graafian follicle will develop into a corpus luteum.
Answer: C
50. The process of separation of sister chromatids does not cause variation.
Answer: C

B.O.D.

In respond to Question 31 Paper 1 SPM 2009

From a study on river X, this finding is obtained: Biochemical oxygen demand (B.O.D) value is high: Which statement is correct about the river:

1. The river is POLLUTED.
2.The content of dissolved OXYGEN is LOW
3.The river contains LESS/NO living aquatic organisms.
4.The DECOMPOSITION activity by microorganisms is HIGH.

Many students get confused over the B.O.D stuff which is related with the BOD experiment to test the pollution in different water samples..

Biochemical oxygen demand or BOD is a chemical procedure for determining the uptake rate of dissolved oxygen by the biological organisms in a body of water.

It is not a precise quantitative test, although it is widely used as an indication of the quality of water.

Moderately polluted rivers may have a BOD value in the range of 2 to 8 mg/L.

Municipal sewage that is efficiently treated by a three-stage process would have a value of about 20 mg/L or less. Untreated sewage varies, but averages around 600 mg/L in Europe.

The following notes will help you to understand more abot BOD:

Microorganisms such as bacteria are responsible for decomposing organic waste. When organic matter such as dead plants, leaves, manure, sewage, or even food waste is present in a water supply, the bacteria will begin the process of breaking down this waste. When this happens, much of the available dissolved oxygen is consumed by aerobic bacteria, robbing other aquatic organisms of the oxygen they need to live.

Biological Oxygen Demand (BOD) is a measure of the oxygen used by microorganisms to decompose this waste. If there is a large quantity of organic waste in the water supply, there will also be a lot of bacteria present working to decompose this waste. In this case, the demand for oxygen will be high (due to all the bacteria) so the BOD level will be high. As the waste is consumed or dispersed through the water, BOD levels will begin to decline.

Nitrates and phosphates in a body of water can contribute to high BOD levels. Nitrates and phosphates are plant nutrients (maybe from organic fertilisers) and can cause plant life and algae to grow quickly. When plants grow quickly, they also die quickly. This contributes to the organic waste in the water, which is then decomposed by bacteria. This results in a high BOD level.

The temperature of the water can also contribute to high BOD levels. For example, warmer water usually will have a higher BOD level than colder water. As water temperature increases, the rate of photosynthesis by algae and other plant life in the water also increases. When this happens, plants grow faster and also die faster. When the plants die, they fall to the bottom where they are decomposed by bacteria. The bacteria require oxygen for this process so the BOD is high at this location. Therefore, increased water temperatures will speed up bacterial decomposition and result in higher BOD levels.

When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria. Since less dissolved oxygen is available in the water, fish and other aquatic organisms may not survive.

Test Procedure:

The BOD test takes 5 days to complete and is performed using a dissolved oxygen test kit.

The BOD level is determined by comparing the DO level of a water sample taken immediately with the DO level of a water sample that has been incubated in a dark location for 5 days.

The difference between the two DO levels represents the amount of oxygen required for the decomposition of any organic material in the sample and is a good approximation of the BOD level.

1.Take 2 samples of water
2.Record the DO level (ppm) of one immediately using the method described in the dissolved oxygen test.
3.Place the second water sample in an incubator in complete darkness at 20 °C for 5 days. If you don't have an incubator, wrap the water sample bottle in aluminum foil or black electrical tape and store in a dark place at room temperature (20 °C or 68 °F).
4. After 5 days, take another dissolved oxygen reading (ppm) using the dissolved oxygen test kit.
5. Subtract the Day 5 reading from the Day 1 reading to determine the BOD level.

6.Record your final BOD result in ppm.


RESULT:

BOD Level(in ppm) Water Quality
1 - 2 Very Good:There will not be much organic waste present in the water supply. 3 - 5 Fair: Moderately Clean
6 - 9 Poor: Somewhat PollutedUsually indicates organic matter is present and
bacteria are decomposing this waste.
100 or greater Very Poor: Very PollutedContains organic waste.

NOTE: Generally, when BOD levels are high, there is a decline in DO levels. This is because the demand for oxygen by the bacteria is high and they are taking that oxygen from the oxygen dissolved in the water. If there is no organic waste present in the water, there won't be as many bacteria present to decompose it and thus the BOD will tend to be lower and the DO level will tend to be higher.

..As for our experiment in our Bio Lab (Malaysian version), we are using methylene blue solution (which is blue in colour ) and will DECOLORIZE faster if there is less dissolved oxygen in the water sample…Vice versa…

…The more polluted the water sample is, the faster the methylene blue solution to decolorise ..

Notes are extracted..TQ
http://www.ciese.org/curriculum/dipproj2/en/fieldbook/bod.shtml

Gills: Gaseous Respiration in Fish

In respond to Question 34 SPM 2009 paper 1: about gills of a fish.

-Just like you and me fish need a constant supply oxygen in the form of oxygen in order to run their metabolism.
-Without oxygen they can't turn their food into energy or make any new fish body. All the free oxygen on this planet,was, or is being, released into the air by plants, the atmosphere at the moment is about 21% O2.
-However oxygen will dissolve in water,
-Fish could of course breathe air like Seals and Whales, and some do, but if they wish to stay safe under the water for longer periods of time it would be much easier if they could get the oxygen they need from the water, and this is exactly what they do. In fact they were doing this long before any vertebrate animals learned how to breath the air.
-So fish live in the water and they breathe the water, to do this they have special organs called gills.

-Gills are wonderfully well designed, and they have to be because although the water does hold some oxygen it never holds any where near as much as the air, and to make things more difficult the amount of oxygen a body of water can hold decreases the warmer it becomes, and also, salt water holds less oxygen than fresh water.
-What this means to the fish is that their gills need to be a lot more efficient at extracting O2 from the water than our lungs need to be at extracting it from the air.
-Fish solve the problems of extracting the O2 they need from the water they live in a variety of ways.
-Firstly they have different life styles, obviously a fish that spends most of its life resting on the bottom of the ocean waiting for its dinner to swim by needs less O2 than a fish which actively chases smaller fish for its dinner.
-However most of the problem is solved in the design of the gills.
-A fish's gills are situated one set on either side of the body and near the back of the head
-In fish there is a bony plate protecting the gills, this is called the operculum, and it is hinged and has muscles attached to it so it can be regularly opened and closed.
-This ability to have water continually passing over the gills is one of the major factors making gills more efficient than lungs.

-With lungs the air comes in, fills the space, and then has to be expelled before any more O2 rich air can be brought in. With gills there is no time wasted getting rid of the old air/water and no energy wasted reversing the direction of the flow..

-In sharks and rays the number of gills is usually 5, but there are some species with 6 or 7 sets, in fish the number of gills is 4 on either side of the body.
-Each gill is supported by a gill arch and protected by gill rakers.
-Each gill arch supports one set of paired gill filaments.
-The gill rakers help make sure that no extraneous material gets into the gill filaments to clog them up.

-Each paired gill filament in turn supports numerous lamellae (sing. lamella), extending out from both sides of the filament body.
It's here in the lamellae that the uptake of O2 actually occurs.
-The lamellae are very fine structures, however there exact dimensions depend on the normal activity levels of the fish in question.

-The more active the fish the thinner they are and the less distance there is between them. Also the absolute thickness of the individual lamellae walls varies, this is important in considering to facility with which O2can diffuse from the water to the fish's blood, the thinner the membrane the more quickly. and easily the O2 can pass across it.
Thus in sluggish fish like the American Brown Bullhead (Amerius nebulosus) the lamellae are 25 µ thick, 45 µ apart and the lamellae walls are 10 µ thick giving you 14 lamellae per mm, whereas in a highly active fish such as the Atlantic Herring (Clupea harengus) the lamellae are 7µ thick, 20 µ apart and the lamellae walls are >1µ in width, giving you 32 lamellae per mm.

-The presence of all these lamellae greatly increases the surface area of the gills, meaning that a large amount of water is available for gaseous exchange at any particular moment of time.

-The Lamellae are basically collections of blood vessels sandwiched between two sets of membranes. The membranes keep the blood and the water separate whilst allowing the dissolved gases, O2 and CO2, to diffuse naturally from one liquid to the other, depending on which has the greater concentration of either gas.

-The laws of physics compel gases to seek equilibrium, if you have different concentrations of a particular gas on either side of a permeable membrane (i.e. a membrane that very small gas molecules can pass through, but not larger organic molecules) then the gas will move from the side with the greater concentration to the other without you having to do anything.
-To ensure a continuous gradient of gaseous difference between its blood and the water flowing past its gills fish use a counter-current system.

-This means that the blood flows along the vessels in the lamellae in the opposite direction to which the water is passing on the outside of the lamellae.

-Fish can breathe the water by swimming forwards and letting some of the passing water flow in through the mouth, across the gills, and then out.

-They can control the amount of blood flowing through their gills, increasing the amount of oxygen they take from the water if they being more active. When they are moving slowly, or resting in the water fish can breathe the water by synchronously expanding and contracting the buccal cavity (the mouth and throat), and the opercular cavity, which is the space behind the operculum where the gills are. In doing this they can pump a continuous stream of water across their gills.
-Most fish can also absorb some O2 through their skin, and while they are in their larval form this is often the main source of respiration.

Extracted notes from sources...TQ
http://www.earthlife.net/fish/gills.html

Digestive system-Paper 1

When you talk about digestive system of man you must be aware of the part which is exactly contains beneficial bacteria!!!...I repeat: beneficial bacteria!!!

Bacteria in your colon are referred to by many different names - probiotics, good or bad bacteria, beneficial bacteria, micro flora, proflora, friendly flora, and unfriendly bacteria.

It refer to all the bacteria that exist in the small intestine and your colon.
Your colon has both good and bad bacteria.
The good bacteria maintain the health of your colon by keeping the bad bacteria from multiplying and reducing constipation.
Most people have bad bacteria as the dominant condition in their colon.
You can see this by the illnesses that exist throughout the world.
Most people later in their life suffer from diseases that resulted from colon neglect and abuse.

Bad bacteria multiples when you,
* Consume poisons such as pollution, pesticides, food additives such as preservatives, coloring, so on.
* Drink alcohol
* Eat processed foods
* Have excess anxiety
* Lack fiber in your diet
* Use drugs and medication

Good bacteria in your colon consists of hundred of species of bacteria.
The good bacteria are most active in a pH of 5.9 to 6.9- an acidic environment. This makes for a healthy colon.
Your colon serves as a home for the good bacteria, which ferment specific carbohydrates, which in turn keep your colon environment slightly acidic.
The acid environment favors the good bacteria and keeps the bad bacteria and pathogens from multiplying.
The bad bacteria create an alkaline environment and are most active in a pH of 7.1 to 7.9
Again, the good bacteria creates an acidic environment and are most active in a pH of 5.9 to 6.9

Acidophilus and Bifidus are the main good bacteria that exist in your colon.
The ascending colon, on the right side of your abdomen area, has the most bacteria.
The quantity of bacteria becomes less in the transverse colon and lesser in the descending colon. Eventually, little bacteria is found in the sigmoid and rectum.

When good beneficial bacteria is dominant, in your colon, it prevents the spread of disease from various organisms - parasites, bacteria, viruses, fungi.

The good bacteria keep these organisms in the minority, thus preventing them from multiplying, getting into the blood, and into the different body organs.
They do this by their antibiotic like secretions, lactic acid production, and other secretions, which keep their environment acidic.

The good bacteria live and thrive on carbohydrates. When your body has good digestion and little carbohydrates reach your colon, the good bacteria population decreases and the bad bacteria become dominant.

In a healthy colon, there are literally billions of beneficial or "friendly" bacteria.

Under favorable conditions, they multiply at a fast enough rate to keep pace with the large numbers that are lost during elimination.
Bacteria is also referred to as micro-organisms.
When they are located in the intestinal tract, they are referred to as "intestinal flora," "micro-flora", "good bacteria", "friendly/beneficial bacteria" or sometimes just "flora."

These friendly bacteria synthesize many important vitamins in the digestive tract including Vitamin K and some of the B vitamins.
A very important function they perform is helping the colon maintain a proper pH or acid-base balance.
It is necessary for the pH to stay in the correct range in order for other health supporting bacteria to exist. It is also important to keep levels of antagonistic micro-organisms under control.

***Colon is an important organ in the digestive system.

15 things that researchers have said cause colon cancer or contribute to its development.
1. Age
Age is the number one risk factor for colon cancer. Does that mean that age causes colon cancer? Not directly. It's just that by age age 50, one in four people has polyps.
2. Alcohol
Research has indicated that alcohol increases colorectal cancer risk.
3. Diabetes
In general, diabetics are up to 40% more likely to develop colon cancer than people who don't have diabetes.
4. Diet
Diets high in fat and cholesterol (especially from animal sources) have been found to cause colon cancer. Low-fiber diets have also been associated with increased risk, but the research isn't as clear
5. Environment
Research has shown that environment can play a big part in colon cancer development. Where you live, who's around you, your occupation, and even when you work may all influence your risk of developing colon cancer.
6. Ethnicity, Race, and Social Status
Does colorectal cancer afflict everyone equally or are some groups of people more likely to be diagnosed than others? The reasons are varied, but some groups get colorectal cancer more often than others. Ethnicity, race, and social status all play a part.
7. Family Medical History
Most colon cancer occurs in people with no family history of the disease. But, colon cancer can run in the family. Whether you're at increased risk depends on which family member was diagnosed and at what age.
8. Gender
You may have heard that men are more likely to get colorectal cancer than women. You may have heard it the other way around, too. Both statements can be true depending on the context.
9. Genetics
Researchers estimate that about 25% of colon cancer cases have some sort of genetic link.
10. Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease, often characterized by conditions such as ulcerative colitis and Chron's disease, increases the risk of developing colorectal cancer. In general, the longer a person has had inflammatory bowel disease, the greater his or her chance of developing colorectal cancer.
11. Lack of Exercise
There's no denying that exercise is good for you. Research has shown that a sedentary lifestyle contributes to colon cancer development.
12. Obesity
Nobody likes to have the word obese thrown at them. But, obesity is a medical term that indicates someone exceeds their recommended weight, one step beyond simply being overweight. And the answer to the question is yes, obesity does increase colon cancer risk.
13. Personal Medical History
Your personal medical history can significantly impact your chances of developing colorectal cancer. A medical history that includes polyps, bowel inflammation, or certain cancers is particularly relevant.
14. Polyps
Virtually all colon cancer develops from adenomatous polyps in the colon, generally referred to simply as colon polyps. A personal or family history of polyps puts you at higher risk for colon cancer.
15. Smoking
Long-term cigarette smoking causes colon cancer for two main reasons. First, inhaled or swallowed tobacco smoke transports carcinogens to the colon. Second, tobacco use appears to increase polyp size.

**Notes are extracted.

One episode has ended...another's coming..

..Thanks to God almighty, Bio papers finally were done...
..Some did it well, some??..as usual: sighing and regretting...for not memorising certain facts of the chapters...
I found the questions were quite straight forward...(Paper 2)...and of course paper 3 was simple...The questions asked were within the syllabus, no extra ordinary...But if you didnt remember facts, then it ws difficult...And if you rely so much on spotted Qs, then you could be dissapointed...
I have my job done,(at least for 2009)..and intend to continue another episode...with my form five-to-be girls (2010)...After Valiants, what will be their batch's name?
..And I will continue publishing the posts, adding more notes and tips according to chapters...and for a time being, to all the form fours (taking biology), the whole of Malaysia, if you happen to bump into my blogspot, be free to browse tru my notes...and i really hope all of you will use it as a reference!..and dont forget to be my followers and leave comments....
...Some of the Diagrams asked in Paper 2...

Bio SPM 2009-REAL

Paper 2:
STRUCTURE:
Q1: plant cell- Golgi apparatus, chloroplast, hypertonic solution [FORM 4]
Qs2:spermatogenesis, Down's syndrome, explain the genetic disorder [FORM 5]
Qs3:stems in different habitat, phloem function, differences between xylem and phloem, importance of mitosis, adaptations of plants is soft muddy soil [ FORM 4]
Qs4: human respiratory system- intercostal muscles, diaphragm, gas exchnage, alveoli adaptation.[FORM 4]
Q5: placenta, umbilical cord, blood compositions in blood vessels of umbilical cord, immunity in foetus, why foetus has separate blood circulatory system frm his mother.[FORM 5]

ESSAY:
Q6:mendel's Law II, haemophilia schematic Diagram [FORM 5]
Q7:Interaction (Rafflesia ), prey-predator biology control, Nitrogen Cycle [FORM 4]
Q8: Transpiration, movement of water molecules in a plant. [FORM 5]
Q9:lipid assimilation, relationship between eating habits and physical condition of the given diagrams.[ FORM 4]

PAPER 3
Q1: The effect of light intensity on the rate of photosynthesis.
Q2: The effect of temperature on the rate of enzyme reaction.