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My name is Poon Cheng Moh. I have been teaching biology in SMK(P) Raja Zarina, Port Klang for 26 years. I sincerely hope that this blog on SPM Biology will be useful to both teachers and students.

Thursday, July 21, 2011

EXPERIMENT CHECKLISTS

No

Topic

Refer to Biology Practical Book


FORM 4

1

Chapter 3: Movement of substance across plasma membrane

Act 3.1 : Size of molecule that can diffuse through a semipermeable membrane (pg 20)

2

Chapter 3: Movement of substance across plasma membrane

Act 3.2 : Studying osmosis using osmometer (pg 23)

3

Chapter 3: Movement of substance across plasma membrane

Act 3.4 & 3.5 : Studying the effects of hypotonic, hypertonic and isotonic solutions on animal and plant cells (pg 27-29)

4

Chapter 3: Movement of substance across plasma membrane

Act 3.6: Determining the concentration of external solution which is isotonic to the cell sap of plant (pg 30)

5

Chapter 4 : Chemical composition of the cell

Act 4.3 : Studying the effects of temperature on salivary amylase activity (pg 36)

6

Chapter 4 : Chemical composition of the cell

Act 4.4 : Studying the effects of pH on the activity of pepsin (pg 39)

7

Chapter 4 : Chemical composition of the cell

Act 4.4 : To investigate the effects of pH on the breakdown of starch by amylase (pg 41)

8

Chapter 4 : Chemical composition of the cell

Act 4.5: Studying the effects of substrate concentration on salivary amylase activity (pg 42) (SPM : Concentration of albumen)

9

Chapter 4 : Chemical composition of the cell

Act 4.6: Studying the effects of enzyme concentration on salivary amylase activity (pg 43)

10

Chapter 6 : Nutrition

Act 6.1: Determining the energy value in food samples (pg 61)

11

Chapter 6 : Nutrition

Act 6.3: Determining the vitamin C contain in various fruit juice. (pg 65)

12

Chapter 6 : Nutrition

Act 6.8 : Studying the effects of macronutrient deficiency in plants (pg 72)

13

Chapter 6 : Nutrition

Act 6.11: Investigating the effects of light intensity on the rate of photosynthesis. (pg 76)

14

Chapter 6 : Nutrition

Act 6.11: Investigating the effects of carbon dioxide concentration on the rate of photosynthesis (pg 76)

15

Chapter 7 : Respiration

Act 7.2 : Investigating the process of anaerobic respiration in yeast (page 85)

16

Chapter 7 : Respiration

Act 7.6: Investigating the differences between inhaled and exhaled air in terms of oxygen and carbon dioxide contents (pg 93)

17

Chapter 8 : Dynamic ecosystem

Act 8.3 :Studying the intraspecific and interspecific competition in plants

18

Chapter 8 : Dynamic ecosystem

Act 8.5 : Investigating the distribution of plants using the quadrat sampling technique (pg 111) Modified (using Grid)

19

Chapter 8 : Dynamic ecosystem

Act 8.6: Estimating the population size of animals using capture, mark, release and recapture technique (pg 113)

20

Chapter 8 : Dynamic ecosystem

Act 8.7 : Studying the relationship of population distribution of an organism with the changes of an abiotic factor

21

Chapter 8 : Dynamic ecosystem

Act 8.11: Studying the effects of temperature, pH, light intensity and nutrients on the activity of

yeast (pg 119)

22

Chapter 9 : Endangered ecosystem

Act 9.2: Investigating the level of pollution in several different sources of water (pg 128)


FORM 5

1

Chapter 1: Transport

Act 1.10 : To study one of the factor affecting the rate of transpiration. (pg 19)

2

Chapter 3: Coordination and response

Act 3.4 : To study the effect of different quantities of water intake of urine output (pg 50)

3

Chapter 4: Reproduction and Growth

Act 4.11 : To study the growth of a plant such as an onion or a balsam (pg 74)

4

Chapter 6: Variation

Act 6.1 : To investigate continuous variation and discontinuous variation in human.(pg 99)

5

Chapter 6: Variation

Act 6.4 : To investigate the importance of camouflage in the survival of a species (pg 106)

Wednesday, July 20, 2011

Vitamin C content in fruit juices

Please read either from Hands on Pg 55 /the sample experiment plan given below :

Objective

To determine the vitamin C content in pineapple, lime and orange juice.

Problem statement

Which fruit juice contains the highest concentration /percentage of vitamin C?

Hypothesis

Lime juice contains higher concentration/percentage of vitamin C compared to pineapple juice and orange juice.

Variables

Manipulated : Types of fruit juice

Responding : Concentration/percentage of vitamin C in fruit juices

Constant : Volume of fruit juices/concentration of DCPIP solution/ Standard concentration of ascorbic acid solution

Apparatus and materials

Materials : freshly prepared pineapple, lime and orange juices, 0.1% ascorbic acid solution, DCPIP solution

Apparatus : 5ml syringe(with needle), 1ml syringe, specimen tubes, 5ml measuring cylinder

Technique

Measure and record the volume of fruit juice needed to decolourise 1 ml DCPIP using a syringe//

Calculate the % of vitamin C in fruit juice by using formula :
Vol of 0.1% ascorbic acid X 0.1
Volume of fruit juice

OR

Calculate the content of vitamin C in fruit juice by using formula :
Vol of 0.1% ascorbic acid (mgcm-3)
Volume of fruit juice

Procedure

1. 1 ml of DCPIP solution is placed in a specimen tube using a 1 ml syringe.
2. 5 ml syringe was filled with 5 ml of 0.1% ascorbic acid solution.
3. The needle of the 5 ml syringe was immersed into the DCPIP solution.
4. Ascorbic acid solution was added drop by drop until the DCPIP solution, and gently stirred with the needle of the syringe. (Do not shake the tube vigorously).
5. Ascorbic acid solution is added continuously until the DCPIP solution is decolourise.

6. The volume of ascorbic acid solution used measured using a syringe and recorded.
7. Steps 1-6 are repeated using fresh orange, pineapple and lime juice.
8. The volume of fruit juices required to decolourise the DCPIP solution in each fruit juice is measured using a syringe and recorded in a table.
9. The percentage and the concentration of vitamin C in each fruit juice are calculated using the above formula.

Precaution:

1. The juice must be freshly prepared.

2. Do not shake the DCPIP too vigorously.

Recording data/ result

Solution/

fruit juice

Volume of solution/fruit juice needed to decolourise 1 ml of DCPIP solution (ml)

Percentage of vitamin C (%)

Conc. of vitamin C (mg cm-3)


1

2

3

Average



0.1% ascorbic acid







Pineapple juice







Lime juice







Orangejuice







Conclusion

Lime juice contains higher concentration/percentage of vitamin C compared to pineapple juice and orange juice. Hypothesis is accepted.

Wednesday, July 13, 2011

Kwashiokor and Marasmus

Kwashiokor
What Is Kwashiorkor?

Kwashiorkor is a disease caused by the lack of protein in a child's diet. Kwashiorkor is a type of protein energy malnutrition (PEM) that is widespread throughout the developing world. Infants and children growing up in tropical or subtropical areas (such as Africa, Asia, and South America) where there is much poverty are at risk for kwashiorkor.

The term "kwashiorkor" comes from a word used in Ghana that means a "disease of a baby deposed from the breast when the next one is born." Kwashiorkor usually happens when a baby is weaned from protein-rich breast milk (for any reason) and switched to protein-poor foods. In impoverished countries, protein-rich foods are difficult to acquire.

What Are the Symptoms of Kwashiorkor?

Children with kwashiorkor have edema (excess water retention in body tissues), which makes them look puffy and bloated. They are weak and irritable, and in many cases their skin flakes, and their hair loses its curliness and color. If left untreated, kwashiorkor causes enlargement of the liver, loss of fluids (dehydration) from the bloodstream even when the child has edema, stunted growth, and severe infection due to a weakened immune system. It also can result in jaundice, drowsiness, and a lowered body temperature.

What is Marasmus?

Marasmus is a form of protein-energy malnutrition occurring chiefly among very young children in developing countries, particularly under famine/starvation conditions, in which a mother's milk supply is greatly reduced. Marasmus results from the inadequate intake of both protein and calories.

What Are the Symptoms of Marasmus?

Marasmus is characterized by growth retardation (in weight more than in height) and progressive wasting of subcutaneous fat and muscle. Other symptoms may include diarrhea; dehydration; behavioral changes; dry, loose skin; and dry, brittle hair. Marasmus can be treated with a high-calorie, protein-rich diet. Severe, prolonged marasmus may result in permanent mental retardation and impaired growth.

Marasmus

Friday, July 8, 2011

Friday, July 1, 2011

To determine the energy value in food samples.

1. Weigh the cashew nut and record its weight.
2. Fill a boiling tube with 20ml of distilled water.
3. Clamped the boiling tube to a retort stand.
4. Record the initial temperature of the distilled water.

5. The pointed end of a long pin is poked into the cashew nut. The other end of the pin is poked into with a piece of plasticine.
6. The cashew nut is ignited by using Bunsen burner and immediately placed under the boiling tube. 7. The flame from the cashew nut is allowed to heat up the water.
8. The water is stirred gently by using a thermometer to distribute the heat evenly. At the same time the rise in temperature is observed.
9. Measure and record the final temperature using the thermometer.
10. Precaution : Make sure that the nut is fully burnt and a shield is put around the nut to prevent heat loss to the surrounding.