Is it Alive?

For today's lab lesson, we were told about carbohydrates and learned that most living things needed glucose to survive. I learned about the different types of carbohydrates, which I have illustrated in this mind map below:

Then, we were given five different substances, labelled A, B, C, D and E. We were to see if these five substances were alive or not.
Firstly, my partner and I took down our observations of the physical appearances of each substance.

Substance A:

-brown-beige colour

-many different sizes and shapes of grains

Substance B:

-cylindrical shaped grains

-beige colour

Substance C:

-not as fine as the other substances

-very consistent circular shape, of the same size

-translucent

Substance D: 

-maroon or purplish blue colour

-consistent circular shape, slightly smaller grains compared to C

Substance E:

-very fine grains of consistent shape

-dark brown colour

Then, we tested each substance's reaction to water. We placed each substance on top of some cotton wool in different sections of a petri dish and applied 4ml of water to each substance, recording their immediate reactions.

Substance A:

-gets darker in colour

-clumps together

-becomes mouldable

Substance B:

-colour of the substance spread onto the cotton wool

-produced a foul smell

-dissolved slightly

Substance C:

-increases in size

Substance D:

-no visible change

Substance E:

-clumps together

Lastly, we tested each substance's reaction to glucose. We poured equal amounts of the substances into individual test tubes and poured in 1.5ml of glucose into each test tube. We recorded their immediate reactions.

Substance A:

-Dissolves slightly

Substance B: 

-Sinks

-Clumps together

-turns into a foam

Substance C:

-Swelled up into irregular, bumpy shapes

Substance D:

-Floats to the surface

Substance E:

-Some stay at the bottom while some float to the surface

After the lab lesson, our Biology teacher advised us to bring home the petri dishes containing the substances in water to observe further changes. We were reminded to keep the substances moist.
After a few days, here are the changes my partner and I observed:

Substance A:

-no further change

Substance B:

-swelled up

-produced more foul smells

Substance C:

-further increased in size

Substance D:

-seedlings began growing out of each grain

Substance E:

-no visible change

Therefore, we concluded that

• Substance A was not alive, as it showed not much reaction to glucose or water. It was most likely sand.
• Substance B was alive, as it produced a foul smell and reacted to glucose and water. It was most likely yeast.
• Substance C was not alive, as it only increased in size in reaction to glucose and water. It was most likely water balls (aka water babies) used in watering plants.
• Substance D was alive, as seedlings began to grow out of each grain after a few days' exposure to water. It was most likely a sort of seed.
• Substance E was not alive, as it showed not much reaction to glucose or water.

However, it was only when our Biology teacher showed us Substance E mixed with a solution of glucose and congo red that we realised that Substance E was, in fact, alive! They were the eggs of a small insect-like creature. 

Above: Substance E in a solution of glucose and congo red. The little white things were swimming!

Above: Substance C (water balls)' immediate reaction to glucose.

Above: Substance D (the seeds)' immediate reaction to glucose.

Get a Grip!

Do we hold all objects in the same way? Create a list of different ways of holding different objects with one hand.

• In a fist, with object inside
• With thumb and index finger
• With thumb and middle finger
• With thumb and ring finger
• With thumb and pinky
• With index and middle finger
• With index and ring finger
• With index and pinky
• With middle finger and ring finger
• Spread across palm
• Spread across back of hand
• Inbetween thumb and palm, with all fingers straight

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

How I hold my water bottle:

The index, middle, ring and pinky finger are wrapped around the circumference of the bottle. The thumb is wrapped around the bottle in the opposite direction for support.

Read the two questions below and discuss with your partner which question is easier to test:
(a) What is the importance of an opposable thumb for the way in which humans use their hands?
(b) Without using your thumbs, can you unpin your nametag from your uniform?

After discussion, my partner and I decided that question (b) is easier to test. Although both questions are about the importance of the thumb in the human hand, (b) would be simpler to test as it is the experiment leading to the conclusion, which is (a).

Shoelace experiment! :)

In this experiment, my partner (Phoebe) and I took turns to see how quickly we could tie our shoelaces with and without tape around our thumb joints.

Above: The time (in seconds) Phoebe and I took to tie our shoelaces without tape around our thumb joints

Above: The time (in seconds) Phoebe and I took to tie our shoelaces with tape around our thumb joints

Conclusion: Our thumbs are very important when gripping objects with our hands. With tape around our thumb joints, the tape restricted the movement of our thumbs and thus we were unable to use it to help us grip our shoelaces and were forced to use our other digits instead.