Scientific Investigation 5/7/2012~ A practical on Ethology, part of Evolution

OBSERVING LIVE SPECIMENS: Case Study on...MEALWORMS

Pre experiment Study: What is Ethology?

In a nutshell, Ethology is the study of animal behaviour. So today's experiment is on the study of mealworms' behaviour.

Using the following diagram, we can formulate an experiment and put it into place to observe mealworms behaviour.

Stage 1: What is needed for an experiment?

Planning an Experiment requires...

1) A general question leading to a specific question with assumptions. The questions must be testable and valuable.

2) The aim followed by the hypothesis. the aim is a statement on what you want to find out and the hypothesis is a detailed prediction with the possible explanation for the expected result. It must be specific and not be a Cause and Effect statement.

3) Variables: namely, Independent (the variable changed based on what one wants to test), Dependent (The variable changed due to change in independent variable, also known as the results) and the Constants (Unchanged factors, remain the same)

4) Control and experimental groups

Control: Serves as a basis for comparison of results, does not have the independent variable, but all other variables.

Experimental: Has ALL variables including the independent variable, the aim you want to find out.

5) The number of subjects: the number of guinea pigs for your experiment must be the same. and testing on all of them is different from...

6) The number of times test takes place.

How many times you conduct the experiment.

Stage 2: Pre-experimental observations on the mealworms (except for taste)

Sight: Brown, small and thin worm-like shape, many distinctly segmented parts on body, 6 legs, 2 antennae (feelers)

Smell: Odourless

Sound: Not really many sounds

Feel: Smooth, can feel the deep divisions very distinctively

The mealworm drawing:

Stage 3: Carrying out some experiments

Experiment 1: Can the mealworms HEAR?

Aim: To find out if mealworms can respond to sound.

Hypothesis: We believe that the mealworm can hear and will respond to sound as sound (or vibrations) are important to ensure that it can get its food.

Procedure:

1) Have 2 groups: Control and Experimental, where each group has 4 mealworms.

2) Control--Assumption of No sound exposure. Observe movement for 5 minutes

3) Experimental--Exposed to the sound of the castanets for 5 minutes Observe movement.

4) Record observations.

Results:

For control group: Mealworms moved in random direction, not moving to anywhere in particular.

For experimental group: Moved towards source of sound, even if location changes.

Hypothesis proven RIGHT!

Experiment 2: Can the mealworms SMELL?

Aim: To find out if mealworms can respond to smell.

Hypothesis: Mealworms can respond to smell as they also need smell to look for food.

Procedure:

Once again the same 2 groups of mealworms who will be our KIND guinea pigs. They are in an air tight container with holes for air to enter.

Control: Assumption that they are Exposed to NO SMELL. 

Experimental: Placed with a vinegar soaked cotton wool piece.

Observe and record movements for 5 minutes.

Results: 

Control group: No change in movement. Random movement.

Experimental group: Moved towards cotton wool before turning away from it.

This once again proves our hypothesis right. However, we were kind of surprised that the mealworms actually moved AWAY from the vinegar since we thought that they would actually not mind vinegar...

Experiment 3: Does it prefer light or dark? Or, can the mealworm SEE?

Aim: To find out how mealworms react when placed under light.

Hypothesis: We think that the mealworms will move away from light. We're not sure why, but it is probably due to the fact that most worms don't really like light. 

Procedure: the same 2 groups of mealworms.

Control group not exposed to any light, placed in darkness.

The experimental group is also placed in darkness, but there is always a patch of light.

Observe movement for 5 minutes.

Results:

Control group: No change in movement, always in random directions.

Experimental group: Moves towards light, but once senses light moves away.

Experiment 4: Can the mealworm feel?

Aim: To find out how mealworms react when being touched by something.

Hypothesis: It will mostly squirm away from most objects.

Procedure: The same 2 groups of mealworms.

Control group is not being touched by any object. However experimental group is being touched by cotton bud and paintbrush.

Observe movement for 5 minutes.

Results: 

There was no difference in the movement of the control experiment. For the experimental group, the mealworms mostly backed away from the objects, although, for the first time, they actually climbed on the cotton bud, then they squirmed away from it.

Modifying your experiment:

The experiment chosen: Light

How would I modify it?

For the experimental setup, ensure that 1 part of the box is in total darkness while the other part is in bright light. Also, one can actually find out if they prefer dak or light by simply counting the number of mealworms in each side of the box in the end, or by just observing how they move.

Is it alive? 27/6/12~a practical, on Evolution

IS IT ALIVE?

Before the Practical...

Some tings to take note of...

1) Characteristics of Living things
2) Conditions to support life

1) Characteristics that have been come up with...

~Ability to reproduce
~Grow
~Die
~Respond to changes (stimuli) in environment (also known as adaptation)
~Evolve
~Move
~Have hereditary information
~Made up of protoplasm (not Cytoplasm but P-R-O-T-O-P-L-A-S-M)
Protoplasm-> Living matter=Cells
*~Excrete liquid waste from metabolism
~Respire
the equation is: O2+C6H12O6-> H2O+CO2+large amount of energy.

In other words, oxygen+glucose-> water+ carbon dioxide+ lots of energy.

* plants do not release solid waste. the term excrete is used for liquids/fluids only.
The term for solid waste is: egestion

2) Condition needed...

Air, food, water, shelter (not all), warmth, energy, adaptation to changes, and light for plants

Also, ~Homeostatis (ability to control) ~Continuity (of own kind) ~Development (growth) and ~Ecology (interactions with other living things) are needed

WARMTH is necessary for all living things because it is needed to carry out all life processes. If there was no warmth then particles would not be able to move and the particles would be just FROZEN. so warmth is necessary.

On to the pre-practical question:

Designing an experiment to test if an object is LIVING.

~Characteristics to test--Respiration
~How to carry out the experiment.
~What evidence will show it's living--Chalky limewater
~Can you infer from evidence that it is living?--Yes, for respiration gives out CO2 and if limewater is chalky means CO2 has been given out so substance is living.

Experiment

Place substance in glucose solution filled container. Place it in an ait tight container with limewater inside. Check after a few hours to see if limewater has turned chalky due to presence of carbon dioxide. This shall prove that the substance is living.




Practical Question:


Testing for life in objects.


Here are the results when substance was put in WATER.


Substance:           Physical appearance:    Changes after 10min:   Evidence/Inference to show life:

A                        coarse and grainy         no change, settles to bottom.

B                        smooth and powdery     clumpy, settles to bottom, cloudy       respiration

C                         hard, transparent, around        expanded                                 growth
                           2mm diameter                

D                        hard and tiny, brown          settles to bottom, no change
                           particles, negligible
                           diameter

E                       Brown, small particles       suspended all over water, no change.


Same was observed for glucose, except for B, where bubbles were observed and glucose was more cloudy.


Pause to Ponder:

Why was glucose used?

Glucose is used for respiration as a form of food. Therefore, to supplement the substances with food, glucose was used.  


3rd part:

Substances placed in soaked cotton wool in petri dish and left for observation.

No changes observed in any of the substances except for D, where plants had sprouted from the particles (now to be confirmed as seeds).

4th part:

Observation of substance E under salt water through microscope.

Picture of substance E in salt water under microscope:

some tadpole like creatures swimming (wriggling) about, past molecules.


Revelation of substances...
E: Brine Shrimp
D: Seeds
C: Water Babies
B: Yeast
A: Sand/Gravel

will continue soon..bb 4 now! :)

Get a Grip! 26/6/12, Evolution

Activity 1: to observe different way of holding objects with our hands

Some interesting words were used to describe ways of holding objects. Here are a few discussed in class.

1) Gripping with thumb and index (pinch)

2) Pinching with index and middle (scissors)

3) 4 fingers at 1 side of object, thumb at other side.

4) 4 fingers around object (small/thin/long) thumb curled and in contact with other side.

5) palm and 4 fingers curling around object.

6) 2 palms touching (scooping)

7) same as 2) but using 4th and last finger

Activity 2: observing and drawing of how I hold my object.

(shown at right)

description of the object: 4 fingers curled around object and thumb curled and on top of the 4 fingers.

My description was accurate enough for my partner to guess how I had held the object. 

Activity 3: Observation of how gorilla moves about and physical appearance of arms, legs, hands, and feet 

This is with reference to the video: OBSERVING PRIMATES

Observations made and differences highlighted between humans' and gorillas' limbs:

FEET: Gorilla has huger gap between big toe and other toes compared to humans.

HANDS: Gorilla has wider digits and "furrier" hands compared to ours.

Some motions of the gorilla: The gorilla moves on fours, with its fists clenched. However, sometimes, it walks on twos. Its limbs, though,  are bent and swing to and fro.

WHY are there such differences?

The black hands (or outer covering) is to enable it to camouflage in its surroundings, so that its predators/prey will not find it.


As for the feet, before we go on, there is one thing to be mentioned here.


Humans have what are known as opposable thumbs. This is because the thumb can only move in the opposite direction of the other 4 fingers. Likewise, this feature is present in the gorillas and most primates. This adaptation is useful to grab items (or stuff, as I prefer to word it). However, some monkeys have prehensile tails (a tail adapted to hold STUFF) to carry out the above mentioned action. 


Moving on...


Now, since gorilla has to grasp on branches and move, therefore, they have opposable toes to grip the branches firmly in order not to lose their balance. 


Enough about gorillas, so let's moo-ve on...


Activity 4: Questions on how primates move.


Some questions to think about...


1) If other primates have opposable toes to grasp onto branches, then why do they need a prehensile tail to grasp onto objects?
2) Why do gorillas need to move in fours when they can easily move in twos like use humans?
3) Why do gorillas have to clench their fist and walk in fours, rather than placing their palms flat on the ground?


Well that's about all for now. Will continue soon so bb :)

Hi :D

An warm welcome to the reader...

Hello there. I am a self confessed freak who loves math and science and HP (not the printer brand but Harry Potter). I currently work/study/um do stuff at Hogwarts School of Witchcraft and Wizardry (in my dreams, in reality, I study at Raffles Girls' School). Well before I digress further, this, as you can see, is my science journal, so yep, you'll only see stuff about science here..well hope you have lots of fun reading this journal...so bye for now. :)

~Swathi