Is it Alive? After 1 Week

These are A, the pile of brown substance, B, yeast which has stained and created holes in the cotton wool, and C, water babies which have increased in size in a clockwise direction.

The section on the left contains E, which are eggs. Some of them have already hatched into shrimps although they were not kept in saline water. The section on the right contains D, which are seeds. These seeds have already germinated into seedlings over the course of the week.

Is it Alive?

This is the physical appearance of the 5 samples at the beginning of the experiment.

We put the 5 samples in 2 types of conditions: moist cotton wool in a petri dish and a test tube filled with glucose solution respectively. Moist cotton wool was used because all living things require water to survive. Water also has an impact on living cells. Hence, we wanted to observe the changes when each of these samples is placed in a moist surrounding. The use of glucose solution is because glucose is a monosaccharide, a basic form of nutrients. It is easily absorbed by even simple organisms. It also provides a source of food for these organisms

After the experiment, we observed these changes

We also observed the sample under tools to magnify them.

 

1 DAY AGO

Is it Alive? Experiment

We did an experiment to test whether 5 samples of substances are alive or not. These are the pictures from the experiment.

These are the initial packets of samples given to us.

First, we did a test for water by wetting the cotton wool with 5ml of pure water in a section of the petri dish and placing a spoonful of each of the substances in the section.

This is a close up shot of substances A, B and C.

This is a close up shot of substances D and E.

 Then, we placed some of the remaining substances into 7ml of glucose solution in a test tube. The substances are A, B, C, D and E from left to right respectively.

This photo shows the substances before stirring. We can see that A, C and D completely sank to the bottom of the test tube, E remains floating and B is separated into 2 layers.

This photo shows the substances after stirring.

This is a picture of substance E placed in a salt solution for a period of time. Substance E is actually eggs of a certain organism and the eggs hatched into white shrimps which can be observed under the light microscope.

Link to the tables: http://biojournal04.blogspot.sg/2013/01/is-it-alive.html

Comparison of Hands

Get a Grip!

Task 1 - We will observe how humans use their hands. Do we hold all objects in the same way? Share with the class how many different ways you can hold different objects with one hand. List them in the journal.

List of different ways of holding different objects with one hand:

1. Picking up objects smaller than the surface of the finger (e.g. rice grains):

-Pressing the surface of the thumb and index finger together with the object held between.

2. Holding light, rod-like objects (e.g. pencil, pen, straw)

-Pressing the thumb and index finger on opposite sides of the object.
(Can be done with the thumb and any number of the rest of the fingers) 

3. Holding thin, flat objects (e.g. paper, books)

-Pressing the thumb on one of the flat sides and any number of the rest of the fingers on the opposite side.

4. Holding objects bigger than the palm (e.g. a pole, waterbottle)

-Resting the palm against the object and wrapping the fingers firmly around the object.

Task 2 -  Reach out one of your hand to hold a water bottle or a pencil case or any object that you can wrap your fingers round. Observe how you are holding the object. Record these observations in detail both in words and also in drawing.

-Refer to Task 1 (4). I put my palm around the object and used my fingers to wrap it. In this case I used all 5 digits.

example: