Evolution of circulatory organs
Answers are for parents and teachers.
1
A heart beats 72 times a minute. How many beats in 1 hour?
4320
2
You counted 38 beats in 30 seconds. How many beats per minute?
76
3
Write the consequence of partial mixing of blood in reptile hearts.
Tissues get less oxygen, so metabolism is slower and body temperature depends on the environment.
4
Write the three steps of evolution of circulation.
Heart and chambers; two circuits; heart divided into arterial and venous parts.
5
Why does a fish heart contain only venous blood?
Blood goes from the heart to the gills, takes up oxygen there, and then passes to the body.