3. maintaining metabolism

Question 1

what is the metabolic rate

Answer 1

the quantity of energy used by an organism per unit time*

*all reactions need an activation energy

Question 2

what can be measured to compare metabolic rates

Answer 2

oxygen consumption, carbon dioxide and heat production

Question 3

what can be used to measure metabolic rates

Answer 3

espirometers, oxygen probes, carbon dioxide probes and calorimeters

Question 4

why do organisms with high metabolic rates require more efficient delivery of oxygen to cells?

Answer 4

because the more energy required by the organism, the more oxygen must be transported to respiring cells

Question 5

describe the circulatory system in fish

Answer 5

single circulatory system - blood only goes through the heart once - one atrium and one ventricle

Question 6

describe the circulatory system in mammals and birds

Answer 6

double circulatory system - blood goes through the heart twice - two atria and two ventricles

Question 7

why are mammals and birds circulatory systems described as complete

Answer 7

mammals and birds have two atria and two ventricles so that deoxygenated and oxygenated blood never mix which means that the circulatory will work more efficiently

Question 8

why are reptiles and amphibians circulatory systems described as incomplete

Answer 8

reptiles and amphibians have two atria but only one ventricle so oxygenated and deoxygenated blood do mix together which makes this system less efficient

Question 9

describe the circulatory systems in amphibians and reptiles

Answer 9

double circulatory system - blood goes through the heart twice - two atria and one ventricle

Question 10

why is a double circulatory system is more efficient at delivering oxygen than a single circulatory system

Answer 10

In a double circulatory system (blood flows through the heart twice for each circulation of the body) oxygenated blood can be pumped out at a higher pressure. This enables more efficient oxygen delivery to cells