Diet

Calorie needs counter:

http://www.afic.org/Burner.htm

Factors affecting calorie needs:.

  1. Age
  2. Gender
  3. Body composition
  4. Activity level
  5. Metabolism
  6. Hereditary factors

Age: Babies need around 800 calories. Calorie needs peak at 25 and decreases as you get older –> The aging body replaces muscle with fat, which burns fewer calories than muscle does.

Gender: Men generally need more calories than women. Women require more calories during pregnancy.

Body composition: People with more muscles will burn more calories.

Activity level: If you do more exercise, you will burn more calories.

(from http://www.dummies.com/how-to/content/what-factors-affect-your-calorie-needs.html)

Calorimetry:

http://www.classzone.com/cz/books/bio_09/resources/htmls/virtual_labs/virtualLabs.html


Analysis

Reflection questions:

Were your predictions correct? What might have accounted for any differences between your predictions and the actual values?
No, my predictions were not correct. I had the misconception that chicken contained more calories compared to grains.

EvaluateHow might multiple trials improve the accuracy of your results?
They will remove human error and make the results more reliable.

ApplyHow can this information be used to help plan a healthful diet?
We can choose foods with more calories if we are doing vigorous activities and vice versa, so that we will not excessively store fats in our bodies.

Evaluate–What are some other pieces of information about food that this experiment did not provide? What else do you need to know to make healthful decisions about your diet?
The vitamins, minerals and fibre content in the foods. Besides these, we also need to know our activity level.

Compare and Contrast–What is the relationship between the release of energy in the form of heat and Calories?
The greater the release of energy in the form of heat, the greater the number of calories.

Self-designed Mealworm Investigation

Date of experiment: 19/7/12

Aim:

To find out whether mealworms prefer food with more water content

 

Hypothesis:

Mealworms prefer food with more water content.

 

Independent Variable: Type of food

Dependent Variable: Number of mealworms around each type of food after 5 minutes

Controlled variables: Temperature, amount of time taken, number of mealworms, mealworms’ distance from each type of food, amount of each type of food

 

Assumptions:

The mealworms can sense the water content in food.

The mealworms are acting according to their natural behaviour.

The apple has the highest water content, followed by the carrot and the oats.

 

Materials:

– 1 apple

– 3 tablespoons of oats

– 1 carrot

– 5 mealworms

– stopwatch

– ruler

– flat opaque tabletop

– weighing scale

 

Procedure:

  1. mark a spot on the tabletop and place a slice of apple, a slice of carrot and a tablespoon of oats 10cm away from the spot and 10cm away from each other. Ensure they have the same mass.
  2. Place 5 mealworms on the spot, orientated facing the apple slice and observe for 5 minutes.
  3. Repeat the experiment twice with the same mealworms.
  4. Record your observations.

 

Results:

Trial 1 Trial 2 Trial 3 Average
No. of mealworms around the apple slice 3 2 3 8
No. of mealworms around the carrot slice 1 0 2 3
No. of mealworms around the oats 1 3 0 4

 

Data Analysis:

  • On average, the greatest number of mealworms were found near the apple slice
  • The mealworms could have been attracted to it due to its high water content
  • However, the oats ranked second in terms of the number of mealworms around it even though it has the lowest water content
  • This could be because mealworms’ main diet consists of oats and eating them is instinctive.

 

Conclusion:

The data supports my hypothesis that mealworms prefer food with higher water content.

 

Troubleshoot:

Use a different set of mealworms for each trial

The mealworms’ behaviour for the second and third trials may have been affected by the amount of food they ate in the first trial. To ensure a fair and accurate experiment, a different set of mealworms should have been used.
References:

tis-science.wikispaces.com/file/view/Andrea-mealworm.pdf

Microscope investigations

Investigation 1:

Magnifying 3 letters on a newspaper

Steps:

  1. Cut 3 letters from a newspaper. They must look different when laterally inverted or upside down. (e.g. R or e)
  2. place it on a glass slide and add 2 drops of water. The letters should be soaked with some water left on the slide.
  3. place one side of the cover slip on the water. slowly lower the cover slip, using a pen to support it. when it is almost flat against the slide, slide the pen out.
  4. Secure the slide on the stage with the stage clips
  5. Observe the letters through the microscope starting at 40x magnification.

Observations:

  • The letters are upside down and laterally inverted (drawing: http://www.scriblink.com/index.jsp?act=phome&ld=1&rid=600&cid=808)
  • When the slide is moved to the right, the image in the eyepiece moves to the left and vice versa
  • I had to turn the adjustment knobs towards me to focus the letters.
  • When I switched to high power magnification, the field of view was smaller
  • I had to center the letters before I switched to high power magnification. If not, I would lose sight of the letters.
  • The position of the image did not change
  • There was a dark line across my field of view (the pointer)

Investigation 2:

Depth of field

Steps:

  1. cut three 1.5cm threads of different colours (blue, black and green)
  2. Repeat steps 2-5 from Investigation 1

Depth of field –> the range of distance where the object looks sharp

Positions of threads:

http://www.scriblink.com/index.jsp?act=phome&ld=1&rid=582&cid=783

Observation:

When I turned the fine adjustment knob, the thread on the first layer (i.e the blue thread) came into focus first, followed by the one on the second layer and so on.

Investigation 3:

Cheek cells

Steps:

  1. Use a toothpick to scrape the inside of your cheek. Wipe the residue on the glass slide.
  2. Repeat steps 2-5 from Investigation 1, using iodine instead of water

Observations:

  • The cheek cells were thin, like paper. Most were clustered on top of each other.
  • The cells had a very simple structure. (nucleus, cytoplasm, cell membrane and organelles)
  • They were stained brown by the iodine
  • Grey specks were floating around the cells

Diagram of cells:

http://www.scriblink.com/index.jsp?act=phome&ld=1&rid=591&cid=796

Investigation 2 – Mealworms!

Name: Avril, Emily (31,13)

Class: 110                    Date: 4/7/12


What is the subtle difference between ethologists and animal behaviorists?

Ethologist

–      the scientific study of animal behavior through observation only

–      no manipulation of animals’ environment (occurs in natural environment)

–      e.g. Jane Goodall

Animal behaviourist

–      involves manipulation of animals’ environment to study animal behavior

–      to a certain degree, occurs in artificial environment

 

Life cycle of mealworms

http://www.sugarglider.com/gliderpedia/index.asp?MealWorm

Image

Image

(from left to right) Mealworm (larva), pupa, adult beetle

Introduction:

Drawing:

Length of mealworm: 2.5cm
Number of segments: 10
Colour: Black head and light brown body

Other observable characteristics:

Physical

–      Body is long and thin, tapering off to a pointed tail

–      Body is made up of many dark brown bands that separate it into segments

–      Body is hard and has a rough texture

–      Length is roughly 2.5 cm; Width is roughly 0.3 cm

–      Has six legs and feelers

–      Legs are at the first 0.3 cm of body (thorax)

–      Resembles centipede

Behaviour

–      Moves forwards with abdomen (without legs) in contact with the ground, dragging behind it

–      The dark brown bands contract on either side of its body to help it curl up or change direction

–      Moults and leaves dead skins/shells that are brown in color, translucent and fragile

–      No noise made

–      Almost constantly eating

Questions:

–      Why is it constantly eating?

–      Can it move backwards?

–      When touched on its back, what is its reaction?

 

 

 

Experiments

1. Light

Aim:

The aim of the experiment – to find out mealworms’ reaction to darkness and light

 

Hypothesis:

In darkness, the mealworms will be located throughout the black box. When exposed to light, the mealworms will be located in the darkest area of the black box.

 

Independent variable – variable to be changed

amount of light in the box

 

Controlled variables – to be kept constant

location of experiment, amount of food in the box, number and type of mealworms, temperature of box

 

Dependent Variable – results to be measured

locations of the mealworms in the box after 1 minute

 

Assumptions:

–       the mealworms can sense light and darkness

–       the mealworms’ locations are only affected by the amount of light in the box

 

Materials and apparatus:

  • 5 mealworms
  • Pen light
  • Black box with a hole covered in plastic at the top and flaps at the bottom
  • Stopwatch

 

Setup:

Image

Procedure:

1. Place 3 mealworms in the middle of the box, between the hole and the flaps. Orientate them facing towards the hole.

2. Close the box and leave it in a dark place for 1 minute.

3. Open the box and observe the locations of the mealworms.

4. Gather the mealworms and place them in the same position as step 1.

5. Close the box and place it in the same dark place. Shine the pen light through the hole in the box for 1 minute.

6. Open the box and observe the locations of the mealworms.

7. Compare the mealworms’ locations in both setups.

8. Repeat steps 1-7 two more times, each time with different sets of mealworms.
Results (common observations between all 3 rounds of the experiment):

When in darkness for 1 minute When exposed to light for 1 minute
–       one crawled under the flaps-       the other 2 are leaning against sides of the box; crawling normally like in the bowl-       their locations are spread out evenly throughout the box –       All mealworms are located away from the bright spot of light in the box-       2 of them are underneath the flaps-       The other is crawling along the side of the box and leaning against the side

–       Their locations are concentrated underneath the flaps

 

Data Analysis – What you observed and give reasons to your observations.

  • They prefer darkness to light
  • The darkness may make them feel safer from predators, so they are more willing to expose themselves in the open
  • Similarly, light may signal predators, causing them to hide
  • Light is often accompanied by heat. The heat with the light may cause water to evaporate faster from their bodies, which will kill them. So they are not willing to expose themselves in light.

 

Conclusion:

The data supports my hypothesis that in darkness, the mealworms will be located throughout the black box; and when exposed to light, the mealworms will be located in the darkest area of the black box.

 

To further improve the experiment:

Seal the black box fully

  • The black box was not fully sealed, so some light was able to enter the box. This compromised part 1 of the experiment where the mealworms were left in darkness and could have affected its outcome.

Replace the pen light with a light source that emits less heat

  • The penlight emitted a lot of heat. This could have affected the mealworms’ locations and the experiment only wants to test their reactions to light, not heat.

 

2. Touch

Aim

To find out how mealworms respond when touched with different objects

 

Hypothesis

The mealworms will react violently when touched with the wooden stick, but will not react when touched with the paintbrush

Independent variable

The object used to touch the mealworm

Constant variables

The number and type of  mealworms, the other components of their environment (e.g. the amount of light and temperature)

Dependent variables

The reactions of the mealworms

Materials

  • 3 mealworms
  • a wooden stick with one end covered in cotton
  • a soft paintbrush

Procedure

  1. Use the wooden end of the stick to brush one mealworm from head to tail
  2. Repeat step 1 with the other 2 mealworms
  3. Use the paintbrush to brush all 3 mealworms from head to tail
  4. Record your observations

Results

When using soft brush to stroke from head to tail

First try:

  • they start writhing and contracting
  • one tilts its head backwards

Afterwards, they stopped writhing, but still contract slightly and stop moving forward.

One of them does not have any reaction at all (does not even stop)

2 out of 3 of them stopped contracting altogether after 3 tries; only stopped slightly while being stroked

 

When use rough wooden side of cotton bud to stroke from head to tail

  • head tilts backwards
  • tries to move forward; more wriggling and “struggling”
  • one of them writhes; another starts contracting slightly; the last one does not respond except by stopping
  • **same reactions for rest of tries

Conclusion

The results partly support my hypothesis that the mealworms will react violently when touched with the wooden stick, however they did react, just less violently than when touched with the wooden stick.

– the other experiment will be added at a later time –

 

 

 

 

Name: Avril, Emily
Date: 29.06.12
Title: Is it Alive?
Aim: To find out whether substances A-E are alive or not

Magnifying Tool

Magnification range

Hand lens  2x (big lens)4-10x (small lens)
Stereoscopefor viewing three-dimensional, opaque objects, such as flowers, insects, mineral specimens, fossils or coins.  20-50x
Light/Compound microscope

  1. for viewing small cells, or thin sections of organs or tissues placed on a glass mounting slide (2D)
  2. The specimens must be thin enough that light can pass through them from below
 40x-1000x

Physical Appearances of substance A, B, C, D and E

Attributes of a sample

  • Size (use common substances as analogies)
  • Shape
  • Colour
  • Texture
  • Smell
Substance Smell Appearance
A Mouldy, damp irregularly-shaped
granular
brown
particles of various sizes, as fine as sand
B Mouldy, damp and warm like pet food/bread Tiny particles
smooth
rod-shaped, more uniformly shaped
muddy-white
C Odourless Regularly shaped
Spherical
Transparent
smooth particles
D Odourless Brown/Black
irregularly-shaped, mostly spherical
smooth particles
E Earthy Tiny
Brown/white
Smooth
spherical particles

Three different types of liquids – water, glucose and salt water are also provided to test the reactions of the substances to these liquids.

Why were these liquids chosen?

  • Water – It is a basic necessity for most kinds of life on Earth. So if a substance is alive, it is likely to react to water.
  • Salt water – some kinds of life may react to salt water but not fresh water, such as marine organisms. It is chosen for the same reason as water.
  • Glucose –Most kinds of life need to respire, a chemical process encompassing food (i.e. glucose) being converted to energy, water and carbon dioxide. So if the substances were alive, they would be likely to react to it and produce CO2 bubbles.

Table 1: Observation of substances A, B, C, D and E in water

Substance
Physical appearance Changes observed after 10min

Inference/ Evidence of life

A  Irregular brown particles at the bottom of the test tube, the water is cloudy. Some particles have dissolved.  No change observed in the particles.
B Sediment at the bottom of test tube, water is cloudy. Some particles have dissolved.  Water is very cloudy and there is a thick substance at the bottom of test tube Formed new substance.
C Particles have expanded and look bumpy. They rest at bottom of test tube  Particles have expanded even more and look coarse. The water level has dropped and some particles are now above the water level C has absorbed water and expanded.
D  Some particles have turned red, tiny white particles at bottom of test tube 2 particles which have turned red are floating. Most particles have turned red. D turned red.
E Many particles are floating at top of water, some are suspended while the rest are at bottom of test tube.  Some particles that were once floating have now sunk to the bottom of test tube. No change observed in the particles.

Table 2: Observation of substance A, B, C, D and E inglucose

Substance Changes observed after 10 mins Inference/Evidence of life
A All particles are resting at bottom of test tube. Water is slightly cloudy.
B Bubbles formed. B has respired
C Slightly enlarged
D Some particles turned red
E Most particles are floating at the surface with some sediment at the bottom

 

 

 

 

 

 

 

 

 

Table 3: Observation of substance A, D and E on wet cotton wool

Substance

Changes observed

Inference/

Evidence of life

After 10 min

After 24h

After 36h

A

 The particles’ colour have changed from muddy brown to a darker muddy brown. Some particles appear slightly translucent.  No changes to particles.  No changes to particles.  –

D

 No changes to particles.  Some particles have split open and germinated. White shoots are growing both upwards and downwards from them. Some shoots have penetrated the cotton wool.  The shoots growing upwards have grown oval green leaves at their tips. D has germinated and is growing. D is alive.

E

 Some particles have turned white.  No changes to particles  No changes to particles  –


(Clockwise from top left) Substances A, D, E after 30hrs


Part 4: All 5 substances were soaked in salt water for 24hrs.

Observations:

  • Substance E: started to move by itself. When viewed under stereoscope, it appeared as tadpole-like organisms swimming by beating “gills” along their sides.

CONCLUSION

Substance

Is it Alive?

Evidence for living or nonliving

Yes

No

A

  √  It did not show any characteristics of life.

B

 √ It respired when it came into contact with glucose.

C

 √ It did not show any characteristics of life.

D

 √ It germinated and grew into seedlings when placed on wet cotton wool for 24 hours.

E

 √ It started to move on its own and respond to stimuli after being soaked in salt water for 24 hours.

Possible identities of substances

A – Sand

B – Yeast

C – Water babies

D – Seeds (from Brassica family)

Another strange member of the Brassica family! Taken from Reader’s Digest August 2012 edition.

E – “Artemia” aka brine shrimp

  • Anthropod
  • part of a genus of aquatic crustaceans known as brine shrimp
  • A prehistoric creature, existed since the Triassic
  • Found in inland saltwater lakes, can live in waters of up to 250% salinity
  • Produces dormant eggs (cysts) which are hatched when needed as food for fish or for testing the toxicity of chemicals
  • also sold as “Sea-Monkeys”

Investigation 1 – Is it alive?