This lab is really short and easy.

start from Question #6

NOTE: please use basic English/ Common language no advances and science words as it’s necessary. The reason is because my professor would prefer using your own language and not copying out of the internet as he will deduct points.

NOTE: answers should be short and simple/ not long just answer for the amount of question is being asked.

Thank you In advance

Question 6. As the size of the cubes got smaller and smaller, what happened to the surface area : volume ratio?

Question 7. Examine Figure 1. For each visible cube in the whole “organism”, count the number of sides exposed to the outside. Write these numbers on the cubes in the diagram. Is there a cube with no sides exposed to the environment in Figure 1?

Question 8. Locate the cube marked “a” in each of the three figures on page 6. Compare cube “a” in the three figures: how many sides of each “a” cube are actually exposed to the outside surface?

Cube “a”	Number of Sides Exposed
Figure 1. 3 x 3 x 3
Figure 2. 2 x 2 x 2
Figure 3. 1 x 1 x 1

Question 9. Referring the Question 8, if each cube “a” were an equal amount of living tissue, which one would lose heat to a cooler environment fastest?

Question 10. Referring to Question 8, if each cube “a” were an equal amount of living tissue, which one would need the fastest heat production to maintain homeostasis of its body temperature? (Remember, Cubus quadrangularis is a mammal.)

Question 11. As an animal grows larger, what do you expect to happen to its rate of heat production per gram of body mass?

Question 12. Based on the reasoning above, you will formulate a hypothesis for the following experiment. Small mice, medium-sized rats and large rats are available in the laboratory. We will measure their rate of oxygen uptake per gram body mass.

1. What is the dependent variable we will measure?

1. What is the independent variable?

1. What are the groups being compared?

1. Now, write the entire formula using the If…, and…, then… format.

Question 13. Which mammal do you expect to have the fastest oxygen uptake per gram body mass? Explain why.

Table 1. Metabolic rate measurements for 3 mammals

with different surface area to volume ratios.

Group 1		Mouse	Young Rat	Adult Rat
Body weight (g):
5 measurements of time required (in seconds) for animal to consume 5000 µL of Oxygen (O2):	1.
	2.
	3.
	4.
	5.
Average time (sec) to consume 5000 µL O2 :
Step 1: Divide 5000 µL O2 by the average number of secondsrequired by animal to consume it:
Step 2: Divide your answer, obtained in Step 1, by the animal’s body weight in grams. This will give you the metabolic rate in µL O2 per 1 second per 1 gram of animal.

Group 2		Mouse	Young Rat	Adult Rat
Body weight (g):
5 measurements of time required (in seconds) for animal to consume 5000 µL of Oxygen (O2):	1.
	2.
	3.
	4.
	5.
Average time (sec) to consume 5000 µL O2 :
Step 1: Divide 5000 µL O2 by the average number of secondsrequired by animal to consume it:
Step 2: Divide your answer, obtained in Step 1, by the animal’s body weight in grams. This will give you the metabolic rate in µL O2 per 1 second per 1 gram of animal.

Group 3		Mouse	Young Rat	Adult Rat
Body weight (g):
5 measurements of time required (in seconds) for animal to consume 5000 µL of Oxygen (O2):	1.
	2.
	3.
	4.
	5.
Average time (sec) to consume 5000 µL O2 :
Step 1: Divide 5000 µL O2 by the average number of secondsrequired by animal to consume it:
Step 2: Divide your answer, obtained in Step 1, by the animal’s body weight in grams. This will give you the metabolic rate in µL O2 per 1 second per 1 gram of animal.

Group 4		Mouse	Young Rat	Adult Rat
Body weight (g):
5 measurements of time required (in seconds) for animal to consume 5000 µL of Oxygen (O2):	1.
	2.
	3.
	4.
	5.
Average time (sec) to consume 5000 µL O2 :
Step 1: Divide 5000 µL O2 by the average number of secondsrequired by animal to consume it:
Step 2: Divide your answer, obtained in Step 1, by the animal’s body weight in grams. This will give you the metabolic rate in µL O2 per 1 second per 1 gram of animal.

Table 2. Metabolic rate for all groups.

	Mouse		Young Rat		Adult Rat
Group:	Mass (g)	Average Metabolic Rate	Mass (g)	Average Metabolic Rate	Mass (g)	Average Metabolic Rate
1
2
3
4
5	XXXX	XXXX	XXXX	XXXX	XXXX	XXXX
6	XXXX	XXXX	XXXX	XXXX	XXXX	XXXX
7	XXXX	XXXX	XXXX	XXXX	XXXX	XXXX
8	XXXX	XXXX	XXXX	XXXX	XXXX	XXXX
Average

1. Analysis Questions

Fill in the Table 3 with the class average data:

Mammal type	Average Mass (g)	Average Metabolic Rate (µL O2 per second per gram of animal)
Mouse
Young Rat
Mature Rate

Question 14. Based on the class data, describe the relationship which appears to exist between a mammal’s size and its metabolic rate.

Question 15. Has your hypothesis been supported by the class data?

If not, where did your reasoning go wrong?

Question 16. Which would you predict to be higher, the metabolic rate of a sparrow or that of a gull? Explain your answer in terms of thermoregulation.

Question 17. To what extent do you think it would be valid to apply this “metabolic rate to body size relationship” to animals other than mammals (clams, insects, fish, frogs, reptiles and birds)? Explain.

Question 18. Is there a thermoregulatory advantage for marine mammals such as whales to be so large? Explain your answer.

Question 19. Suggest a reason why there are no rat-sized marine mammals.

Question 20. If an animal is an ectotherm, which is without internal physiological thermoregulation, how does it manage to survive when the weather is very hot or very cold? Give an example.