Study of the rate of respiration in flower buds leaf tissue and germinating seeds


The rate of respiration in plants is quite different from the aspects of photosynthesis. It is to be found in plants is different in different regions. The rate of respiration in leaf tissues, flower buds and germinating seeds is discussed further in the tutorial.

What are Flower Buds, Leaf Tissues, and Germinating Seeds?

Definition of flower buds, leaf tissues, and germinating seeds is mentioned below −

Flower Buds

This part of the plant helps in producing a flower. Mostly they are found in terminal ends. It makes them easier to be identified. There are different kinds of flower buds to be found in a plant. Some of them are namely alternate, opposite, and whorled buds. Others include terminal buds that are found at the tip of the stem and the buds found in unexpected regions are called adventitious buds.

Germinating Seeds

Figure 1: Seed germination

The process is associated with the growth of plants from seeds. The process helps in the plant growth starting from a single species. It influences the quality and quantity of crops. A variety of plants with a better rate of seed germination improves the crop yield. The seed germination takes place through various stages.

Leaf Tissues

Figure 2: Leaf Tissues

These tissues are commonly found in the leaves. There are three kinds of them; the epidermis, mesophyll, and vascular tissue. These tissues are made of different cell layers.

Aim of the Experiment

To study and assess the rate of respiration that takes place in flowering buds, leaf tissues, and germinating seeds.


Figure 3: A Ganong’s Respirometer

The rate at which the aforementioned part of plants breathes is calculated with the assistance of Ganong’s respirometer.


The apparatus required for the experiment is mentioned below −

  • In order to assess the material that respires, a bulb is located atop that ends in a 10% KOH solution along with a miniscule bulb located at the bottom. The bigger bulb contains a stopper along with a lateral hole in it. This hole would assist in atmospheric association along with stopper regulation.

  • A graduated manometer is attached to the bulb.

  • A levelling tube is attached to the manometer with a rubber tube. The setup is made to stay erect and stable.

Materials Required

The materials required for this experiment are as follows −

  • 10% KOH solution.

  • Ganong’s respirometer.

  • Germinating seeds, flower petals, or leaf tissue.


The procedure of this experiment is mentioned below −

  • 2ml of the considered materials are to be taken and put inside the bigger bulb of the respirometer.

  • 10% of KOH to be added to the manometer.

  • The air in the atmosphere is moved to pressure by regulating the bulb stopper. The regulation goes on until the bulb and the hole coincides.

  • The tube is to be level such that the KOH solution attains 100m at the manometer’s base.

  • The respiring materials are to be closed with 100ml of air.

  • The glass stopper found at the top is to be turned to cut out atmospheric air and this begins the observation.


Observations noted are as follows −

  • The solution in the manometer continues to rise as the respiration continues inside the setup.

  • Readings are to be taken at an interval of 10 minutes till the 80ml mark, implying the volume is 20ml since the presence of aerial oxygen is 20%.

  • The liquid is to be brought to equal mark in the tubes involved.

  • The outcome can be measured with the carbon dioxide coming from respiring materials.


The following liberation is observed −

  • The generated carbon dioxide is consumed when it touches the KOH solution since the oxygen is accumulated. The KOH solution increases in the manometer tube

  • The rate of rising of KOH solution is assessed from the rate of aerobic respiration which is calculated in terms of oxygen volume consumption per unit time and 2ml of the taken materials.

  • A fifth of the air’s volume is made of oxygen. Hence, 20ml of oxygen is present in 100ml of air in the respirometer.

  • Therefore, the reading is taken until the rise of 20ml in the volume of the solution of KOH. Anaerobic respiration begins after this mark.

By conducting the experiment on various taken materials the following inferences can be made −

  • Actively growing meristematic tissues are found to have a higher rate of respiration when compared to older or more matured parts of the plant.

  • A relation can be established between the quantity of protoplasm and the rate of respiration where they are found to be directly proportional. Younger cells have more protoplasm.

  • Mature cells are vacuolated and so they have lower rate of respiration.

  • The experiment shows that flower buds have a higher rate of respiration in comparison with leaves.

  • The highest rate of respiration is found to be in germinating seeds as the water level is highest for the experiment involving germinating seeds.


The entire course of the experiment reflects upon the aerobic respiration of the considered materials under optimal conditions being catered to them. The presence of oxygen in the atmospheric air is crucial for the entire course of the experiment. The Ganong's respirometer is the setup that reflects on the course of respiration that takes place in various sections of plants.


Q1. What are germinating seeds?

Ans. It is a crucial process that assists different species of plants to grow from a single seed into a full-grown plant. This stage is crucial in the quality of crops and the associated crop yield. The most common example of seed germination is found in the sprouting of a small seedling from a seed.

Q2. What is plant respiration?

Ans. The respiration found in plants is an important procedure along with photosynthesis. It is the process through which sugar is created during photosynthesis is further bound with oxygen to generate energy for the plant body. There are two kinds of respiration found in plants, dark respiration, and photorespiration.

Q3. What is the rate of respiration in different parts of plants?

Ans. The rate of respiration is higher in young and active meristematic tissues that are still growing as compared to the mature regions of a plant. The highest rate of respiration is found in the root and the tips of stems as they are still in the growing phase. The dormant seeds and the spores are known to have the lowest rate of respiration in a plant body. The richness of meristematic tissues in the growing marks the increase in the rate of respiration in plants.

Updated on: 24-Apr-2023


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