Friday, April 26, 2013

Decomposers and Keeping the balance in the food chain/web

Dear all,

You can do it! Last lap and counting down to your SA1. It is time to put in more hard work and work the socks off to ace your examinations. The first hurdle begins next week in your Oral Examinations. Please get some practice this weekend.

Here is a recap of what we have done today:

English

We discussed about your oral techniques. Let us recap.

1. For your reading passage, read carefully. Be clear, audible and read with expression. Be natural. You do not need to slang your voice. Remember to stress on the important words and express yourself, especially for the conversations. 

2. For your picture description, it is important to describe the picture in details. Look carefully and like writing a composition in your mind, you must have an introduction, main events and conclusion. Here is one example:

Introduction:
This picture shows/depicts a scene at a playground. It is probably a weekend or evening time as there are children playing at the playground. They are here to relax themselves. 

Main events:
**Use your DIEO method. D - describe (appearance and actions of the characters) I - Interpret the feelings of the characters. E - Elaborate and explain why they feel that way. O - Give your Opinion.

In the middle of the picture,  there are two naughty children standing on the swing and a man in stripe pants telling them off. One of the children has his back facing the man and both of them seem to be feeling mischievous and happy as they are smiling cheekily. In my opinion, they should not be standing on the swings as it is dangerous and if it breaks, they will suffer injuries. The man in stripe pants is doing the right thing by telling the naughty children off. They should heed his advice. 

At the top right hand corner of the picture, there are four children playing by themselves. Two of them are riding the toys. They seem to be happy as they enjoy themselves. In my opinion, they are doing it the right way and the two naughty children in the middle of the picture should follow their actions.

Conclusion:
In conclusion, the playground is a public area for us to enjoy ourselves and share the facilities. It is important for us to observe safety rules and not endanger ourselves. We must learn to be considerate and gracious and not break the rules. 

3. Conversation

- A possible conservation could be linked to the reading passage and picture. In this case, I may ask about "Tell me an experience you had in a public place". 

- Same as your picture discussion, you need to formulate an introduction, main events and conclusion. 

Introduction:
I have been to many public places before such as shopping centres, hawker centres, parks and community centres. I have had many experiences at such areas, both positive and negative. However, I had one unforgettable experience!

Main event:
It was one particular day at the hawker centre and it was very crowded. My family and I were there for lunch. We were waiting around patiently for available seats. Just then, I spotted a table of people about to leave and signaled for my family to join me. As we were about to sit down, a group of 3 teenagers came rushing towards the table and immediately sat down before we could sit down.

We were so upset and asked them why they had done so. They did not apologise and scolded us harshly, saying that the table was not owned by us. My family did not want to argue any further and quickly left the place in disgust. We manage to get a seat later on. 

Conclusion:
This incident has shown me that there are people who are rude and inconsiderate. We should learn to share and be gracious in the public area and not act selfishly. After all, public areas are meant for everyone. 

Science

We have wrapped up on the topic of food webs and food chains with only the workbook activity and topical worksheet to be completed. Then, we will move on to adaptations next week before the revision paper will be given to you next weekend to be done. 

Today, we discussed about the importance of keeping the balance in the ecosystem and food chains/webs. It is important to keep a balance as a change in the population size of one organism will affect the other organisms in the food chain/web. 

Plants --> Caterpillars --> Birds --> Snakes 
In this particular example, if the caterpillars decrease in numbers, the population size of birds and snakes will also decrease as firstly the birds will have fewer caterpillars to consume. As a result, their population size will decrease. Secondly, the snakes will have fewer bird to consume and this will also result in a decrease in the snake population. The plants will experience an increase in numbers as there are fewer caterpillars to consume it. 

In this example, there are 2 predators (Birds and snakes), 1 producer (Plants) and 3 consumers (Caterpillars, birds and snakes). Also, there are 2 preys (caterpillars and birds). The bird is also both a prey and predator. 

A predator is an animal which eats other animals. They are often carnivorous or omnivorous. Herbivores ARE NEVER PREDATORS. 

A consumer is an organism which consumes any other organisms. They can be carnivorous, omnivorous or herbivorous. 

 Decomposition is carried out by fungi and bacteria. It attacks the body, especially the dead cells. So when organisms die, they do not have the cells and antibodies to fight against the bacteria and fungi. However, decomposition is important as it breaks down dead organisms or matter into smaller parts into the ground. With that, the nutrients are soaked into the soil and gives the soil nutrients. 




Happy revising during the weekends,
Sincerely,
Mr Nelson Ong

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