spongesSponge Animals: Growing Insects

Materials: Growing Insects (toys), ruler, water, warm water, tweezers

Question: How does water temperature affect the rate of growth of a sponge animal.

To answer this question, you will need to gather data as your "animal" grows and plot its size on a line graph.

Experiment Design:

1. Pick two animals of the same form (the animals are "assorted", but make sure you have a matching pair to make a comparison)   Measure the length and weight of the insects at start time (Time 0)
2. Place one insect in room temperature water, and the other insect in warm water.
3. Measure the length of the insects in cm as they grow (approximately every 5 minutes) and weigh the insects at 15 min, 30 min and the following day.

Data Table

Insect 1

Insect 2

 

 

 

Insect 1

Insect 2

Time (min)

 Room Temperature

Warm Water 

 

Room Temp

Warm Water

0 (start)

 

 

Starting Weight

 

 

5

 

 

             

 

 

10

 

 

 

 

 

15

 

 

Weight After 15 Min

 

 

20

 

 

 

 

 

25

 

 

 

 

 

30

 

 

Weight After 30 min

 

 

35

 

 

 

 

 

40

 

 

Weight After 1 Day

 

 

Graphing

Graph TWO LINES on the grid below. Place time on the X axis and length on the Y axis. Label each line and the graph axes.

graph

 

Analysis

1. Why was it important to choose the same type of insect for growing?

 

2. Which type of water made the insect grow faster? How do you know this for sure?

 

3. Examine this graph of worms as they grow.

wormgraph

A) Which worm had the fastest rate of growth? ______

B) Which worm had a constant rate of growth? ______

C) How big was worm A on Day 15 ? _____ How big was worm B on the same Day? _____

D) How big were both worms on day 25? _______

4. Growth rate can be measured by calculating he SLOPE of a line on a graph. To calcuate the slope, you need to pick two points on the line. Let's use WORM B to calculate a slope (m).

equation

What is the slope of WORM B's Line (show work above)? _____________

5. Once you have the slope (m) calculated, you can create an equation that can be used to PREDICT growth patterns.The equation for a line is

y = mx + b

m = the slope (you calculated in #4)
b = the point where the line crosses the Y axis, in our worm's case, b = 22

Write the full equation, plugging in the numbers for m and for b: ________________________________________________

6. Now that you have the EQUATION, you can use it to calculate how big your worm will be in on DAY 30.

Show calcuations and answer:

 

 

7. The same number can also be estimated by extending the LINE out to Day 30 and using the graph. Show on the worm graph above where worm b's line would be on day 30 (assuming its growth remained constant).

worm8. How big will your worm be on Day 500 (assuming a constant rate of growth)?

Show your calculations and answer:

 

 

Is this a realistic number? Why or why not?