Tutor Niedino: Pri Science Questions and Concepts

[atutor2001]

24hr-mum:

is plastic made of things that were once alive (i read from a guide bk that is it made from crude oil whc come from remnants of living things that died long ago), or is it made from things nvr alive?


what does moss and fern feed on? is it feed on living things?

can they make their own food since they are plants?

is yeast a fungi or a kind of micro-organism just like bacteria?

Wow your questions are very interesting.

1. Part of the components for making plastic comes from crude oil (which is once alive). However, in Pr sch, kids are taught that plastics are made from things that are never alive because the crude oil itself has been changed/broken down into a different chemical compound before it can be made into plastic i.e. the original chemical structure of crude oil itself cannot be made into plastic. (unlike say wood for making furniture, we do not need to change the chemical structure of wood before making the furniture)

2. The word \"feed\" is ambiguous. Animals feed on others to get \"food\" and \"nutrients\". (\"food\" is to provide energy while \"nutrient\" is to provide raw materials for growth) However, plants do not \"feed\". Plants can make its own food and absorb nutrients from the ground. For moss and fern that grow on other living things e.g. trees, they still make their own food but they absorb nutrients from the living things that they grow on. If \"feed\" is to mean the process of absorbing nutrients, then we can say that ferns and moss \"feed\" on living things provided the picture shows them growing on a living thing. They can also \"feed\" on the ground.

3. Yeast is a single-cell organism and cannot be seen with our naked eyes. Micro-organisms are living things that we cannot see with our naked eyes. Therefore, yeast is a micro-organism.

Regards

[24hr-mum]

thanks for ur clear explanation. but i thot yeast is a fungi??

[atutor2001]

24hr-mum:

thanks for ur clear explanation. but i thot yeast is a fungi??

Yes, yeast is a fungi and is also a micro-organism because we cannot see a \"single\" yeast cell with our naked eyes.

Alga (a type of algae) is also a micro-organism because it is also single-cell and cannot be seen with our naked eyes.

Therefore not all micro-organisms are bacteria, there are others like amoeba, paramecium,... which are not bacteria.

Regards

[atutor2001]

24hr-mum:

thanks for ur clear explanation. but i thot yeast is a fungi??

Yes, yeast is a fungi and is also a micro-organism because we cannot see a \"single\" yeast cell with our naked eyes.

Alga (a type of algae) is also a micro-organism because it is also single-cell and cannot be seen with our naked eyes.

Therefore not all micro-organisms are bacteria, there are others like amoeba, paramecium,... which are not bacteria.

Regards

[atutor2001]

sorry double posting

[24hr-mum]

i see. so some fungi eg yeast is also mico organism while some fungi such as mushrm, are not.


what is paraceium, alga and amoeba?
looks like there are tons of things to read up …

[atutor2001]

Paramecium and amoeba are found in water. They belong to a family of micro-organism called protozoa (if I remembered correctly)


Regards

[anneshirleygilbert]

How do you answer this question on Heat and Temperature the Singapore PSLE way?


Scenario : John nd Mary walked into an air-conditioned shopping centre during the daytime. They made the following comments:

Mary : Brr … it’s freezing cold in here.
John : Are you kidding? It’s so hot!

Q1. One of the teenagers above had just spent an hour packing frozen meat in the coldroom of a meat factory next to the shopping centre. Who is it?
Ans: John (easy enough)

Q2. Explain your answer.
The answer given in the assessment book is : "Since John packed frozen meat in a coldroom, he would feel very cold. When he next walked into the shopping centre, he could feel the effect of the increase in temperature more intensely. This made him feel hotter than it actually was."

But my daughter said her science teacher said science questions must be answered the science way : meaning the words ‘heat gain’ and ‘heat loss’ must be used.

How would you answer this question to the satisfaction of the graders? Pls help.

[sunshine0809]

Heat travels from a region of higher temperature to a region of lower temperature.Since John was in the cold room (lower temperature) before going to the shopping mall(higher temperature), he would gain heat from the surrounding in the shopping mall.Thus, he feels hot.

[greenbean2011]

dear Niedino,


from your experience, have you come across any book that contain all misconceptions written on Science concepts, topic by topic ? if Yes, can kindly recommend - by which publisher, author ?

truly appreciate, Thanks a million !