Q&A - PSLE Science

[atutor2001]

meimeitan:

Hi All,


I have come across the following questions. May I know the possible answer?

Mr Goh concluded that the increase in his height from birth until he was 21 years old was due to cell division. What other factor contributed to this increase in height?

Is the answer 'cell growth'?

Thanks.

meimeitan

You are correct. Just some additional points you may wish to know :

There are 2 purposes/functions for/of cell division :
1. To replace old or damaged cells
2. For growth (i.e. increase the number of cells)

There are 2 definitions for cell growth :
1. Increase in number of cells - this is the reason for an organism growing bigger. (When an organism reaches matured stage, cell growth will slow down and finally stop. Then cell division is only for replacement purposes.)
2. The cell itself growing bigger - this is the process of a cell development

Many kids find above confusing.

[tianzhu]

Hi


When answering science questions, the terms key words and concepts are frequently mentioned.

What are key words and concepts?

Let’s pick a topic, say Heat.
What are the keywords and concepts in Heat?

Please share your view?

Best wishes

[meimeitan]

Hi All!


Do any one knows if the mircowave or photocopier has sound energy or kinetic energy?

thanks

meimeitan

[Tang]

meimeitan:

Hi All!


Do any one knows if the mircowave or photocopier has sound energy or kinetic energy?

thanks

meimeitan

Hi,


Both have sound energy and kinetic energy.


Microwave - A circular disc turns -- kinetic energy. When time is up, it clinks -- sound energy.

Photocopier - Paper moving -- kinetc energy. When paper moving, there is a shuffling sound -- sound energy.

[Tang]

tianzhu:

Hi


When answering science questions, the terms key words and concepts are frequently mentioned.

What are key words and concepts?

Let’s pick a topic, say Heat.
What are the keywords and concepts in Heat?

Please share your view?

Best wishes

Hi,

Here are some terms:

Heat flows, heat travels

Heat gains, heat loss

temperature

good conductor of heat / poor conductor of heat

slows down heat loss / slows down heat gain

hot region / cold region

melting point / freezing point

boiling point

solid / liquid / gas

gains heat and expands

loses heat and contracts

.......

[meimeitan]

Hi Tang,


thanks

meimeitan

[tianzhu]

Hi


You may find this site useful.
http://www.epopular.com.sg/my-kid/score-in-science-10-tips-for-better-grades.php

Best wishes

[meimeitan]

Hi! All,


Is the statement "potential engergy in fossil fuel originates from the Sun" correct?

thanks.

meimeitan

[starlight1968sg]

meimeitan:

Hi! All,

Is the statement \"potential engergy in fossil fuel originates from the Sun\" correct?
thanks.
meimeitan

Fossil comes from dead plants or animals being buried deep down the earth. Before they die, they obtain their energy from the Sun. :oops:

[meimeitan]

Hi! starlight1968sg


thanks.

Another question is "Does an object lying on the ground have gravitational potential energy?"

Your prompt reply helps me a lot. thanks.

meimeitan