Date: January 16, 2025
Title: Respiration
Aim: To investigate the effect of exercise on breathing rate.
Apparatus and materials: stop watch
Method:
1. The student sat quietly for 2 minutes to ensure complete relaxation.
2. The number of breaths taken in one minute was counted and recorded in a
suitable table.
3. Step 2 was repeated every other minute, for a total of four counts.
4. The student then did vigorous exercise by stepping up and down the stairs
for two minutes.
5. Immediately after exercise, the number of breaths taken in one minute was
counted and recorded.
6. The breathing rate was monitored every other minute until it returned to the
resting rate.
7. : A graph of Average number of breaths against time (in minutes) was
plotted.
Discussion:
1. What is breathing?
2. What is respiration?
3. What does number of breaths per minute/breathing rate indicate?
4. What is the average number of breaths at rest/ before exercise?
5. Account for the differences in number of breaths before and after exercise?
6. How long after exercise does the breathing rate return to the breathing rate at
rest?
7. What is oxygen debt?
Limitation/source of error:
Conclusion
Breathing is defined as the rhythmic process of air entering the lungs known as
inhalation and air leaving the lungs known as exhalation to facilitate gaseous
exchange in the environment. This process is often confused with respiration which
is the metabolic process by which living organisms obtain energy in the form of
ATP (adenosine triphosphate) ; which is also done with breathing. The number of
breaths per minute indicates the respiratory rate of an individual. Using the results
of this experiment the average number of breaths taken at rest is 18 which is
verified by research that states that 12-18 breaths per minute is the average rate of
breathing for an adult. In this experiment differences between breathing rate before
and after exercise are observed as before exercise the 1st minute around of breaths
were 20 but after exercise they skyrocketed to 55, for the 7th and last minute after
exercise is 22 and before is 19. In terms of average before exercise is 18 and the
average breaths after exercise has a sizable increase to an average 35 breaths. It
takes 7 minutes for the breathing rate to become close to normal after excercise.
Oxygen debt is the term used to describe the oxygen needed to oxidize lactic acid
which is built up after vigerious excercise.
: Breathing is defined as the rhythmic process of air entering the lungs known as
inhalation and air leaving the lungs known as exhalation to facilitate gaseous
exchange in the environment. This process is often confused with respiration which
is the metabolic process by which living organisms obtain energy in the form of
ATP (adenosine triphosphate) ; which is also done with breathing. The number of
breaths per minute indicates the respiratory rate of an individual. Using the results
of this experiment the average number of breaths taken at rest is 18 which is
verified by research 1that states that 12-18 breaths per minute is the average rate of
breathing for an adult. In this experiment differences between breathing rate before
and after exercise are observed as before exercise the 1st minute around of breaths
were 20 but after exercise they skyrocketed to 55, for the 7th and last minute after
exercise is 22 and before is 19. In terms of average before exercise is 18 and the
average breaths after exercise has a sizable increase to an average 35 breaths. It
takes 7 minutes for the breathing rate to become close to normal after excercise.
Oxygen debt is the term used to describe the oxygen needed to oxidize lactic acid
which is built up after vigerious excercise.
Limitations/Sources of Error:
Sex Determination;
Aim: To investigate how the sex of an offspring can be determined.
Apparatus and materials: 25 white beads, 75 black beads, 4 beakers
Method:
1. Fifty black beads were placed in a container. In another container 25 black beads
and 25 white beads were placed together and mixed thoroughly.
2. The beakers were placed side by side with two empty beakers clearly labelled A
and B.
3. Students were instructed to close their eyes and Pick one bead from each of the
first two beakers. If both beads were black and the other white, they were placed in
beaker B.
4. The results were recorded in a suitable table, to show the combination of beads
produced each time.
5. The beads were selected another nine times, making ten selections in all.
