Conducting biology experiments is essential as it introduces students to hands-on experiences and breaks the class monotony. Teachers use experiments to engage the students and make them curious about how the ecosystem works. Plant physiology experiments help students understand nature better, and the investigations open their minds to explore the possibilities. Lab experiments allow biology to make more sense, and if teachers are lucky, the experiments unlock particular passions in some of their students that they may pursue in the future.
Experiments For plant physiology Lessons
Below are some of the best experiments for students to study plant physiology:
Effects of Temperature on Cell Respiration
Cell respiration is a sequence of enzyme-catalyzed processes that break down carbs, proteins, and lipids into carbon dioxide and water while releasing energy. Hydrogen is extracted from the fuel molecules and oxygen is consumed throughout the process. Students use this knowledge to monitor oxygen consumption and hydrogen liberation in growing barley at various temperatures.
The experiment includes eight calibrated respirometers for measuring oxygen consumption as well as the reagents needed for the graphic dye reduction test. The activity exposes students to a basic biological process while also providing information on seed shape and germination.
Extraction and Analysis of an Enzyme from Wheat
Many plant tissues contain acid phosphatase, which catalyzes the removal of phosphate groups from macromolecules at low pH. Students produce a cell-free wheat germ extract and estimate the quantity of enzyme contained in the extract in this experiment. The experiment provides hands-on experience with enzyme extraction methods as well as a solid foundation in enzyme activity analysis and basic enzyme kinetics.
A colorimeter can come in handy in this experiment but is not necessary.
The Nucleosome Structure of Chromatin
In eukaryotes, the DNA molecule is wrapped around histone proteins to form nucleosomes, which are the most basic level of chromosomal structure. Nuclease digestion experiments provide support for the “beads on a string” concept. The enzyme cleaves the linker DNA between nucleosomes (the string) but not the nucleosomal core DNA when nuclei are treated with micrococcal nuclease (the beads).
When the DNA separated from these nuclei is electrophoresed on agarose gels, it forms a ladder pattern, with each band’s length indicating a multiple of the nucleosomal unit. Students analyze nucleosomal DNA from calf thymus that is included in this chemical package using this background knowledge. They then make nuclei from wheat germ, treat them with micrococcal nuclease, then use electrophoresis to look for a ladder pattern in the DNA. This project requires two 2–3-hour laboratory sessions.
Plant Molecular Biology
Higher plants’ chloroplast genomes are small and simple. There are approximately 120 genes in this genome that code for chloroplast proteins. In this experiment, Students will isolate chloroplasts from fresh spinach before extracting DNA from the organelle. The DNA is digested using EcoR, separated by electrophoresis, and transferred to a nylon membrane.
Hybridization using a biotin-labeled probe generated from a plasmid carrying the ribosomal gene sequences detects the DNA fragments containing the ribosomal genes. The process requires fresh spinach, microscopes, ethyl alcohol, a water bath incubator capable of maintaining a temperature of 60-65°C, and a centrifuge capable of operating at a force of at least 3000 x g. A microcentrifuge is also useful, although it is not required.
Enzyme Kinetics
The purpose of this experiment is to provide students with a fundamental knowledge of enzyme kinetics. Students produce a wheat germ extract in the first experiment in this series. The initial velocity (Vo) of the reaction catalyzed by pure acid phosphatase and the acid phosphatase activity contained in the extract is also measured and the quantity of enzyme contained in wheat germ is estimated.
The student will then investigate the impact of substrate concentration on reaction velocity in the second experiment. Michaelis-Menton and Lineweaver-Burk plots are used to evaluate the data, and students compute Vmax and Km values.
This experiment includes:
- Wheat germ,
- Acid phosphatase,
- Extraction buffer,
- Acid phosphatase substrate,
- Substrate dilution buffer,
- Nitrophenol standards,
- Small transfer pipets and large transfer pipets.
Temperature Effect on the Xylem in Tomato Plants
This experiment aims to test how exposing the xylem in tomatoes to different temperatures will affect plant growth. The necessary equipment for the experiment includes six pots, tomato plants, soil, blue dye, water, ice, heat lamp, thermometer, beakers, and microscopes. The students will put the plants in the pots and add soil to bury the roots. The six pots of tomato plants will be placed in different strategic locations, under the heat lamp, in ice, under shade, in the sun, in the fridge, and the freezer. Each pot will receive an equal amount of water and blue dye every day. Observe and record the observations every day for three weeks. After three weeks:
- Gather the plants
- Cut a piece two inches from the roots
- Examine the xylem under a microscope
Students should note the difference in sizes and conclude on the temperature effects on plant xylem.
Growing Plants from the Top of a Carrot
This experiment aims to determine whether plants can get the nutrients they require to grow from a carrot. The requirements include four carrots, containers, and water.
- Place the carrots in different containers and cut them carefully. The cut side should face down, then add water to the top.
- Place the containers near the window for them to access light and observe changes daily.
- Use a ruler to measure the extent of growth of roots and keep a record.
- Collect data for a week and let the students conclude from the observed results.
How Roots Grow When the Direction of Gravity Changes
This experiment aims to understand the effects of gravity on plant growth. Plants respond to gravity as the roots grow towards it, and the stem sprouts in the opposite direction. In this project, the students will alter the direction of plant growth and watch how they respond to gravity. The materials are blotting paper, radish seeds, CD cases, rubber bands, water bottles, modeling clay, and a dark closet.
- First, moisten the blotting paper and place the radish seeds on the CD cases, then number as required.
- Next, use the modeling clay to hold them in place and put all the seeds inside a dark closet.
- For about two to three weeks, measure the root growth and angle using a protractor from time to time.
Gardening Without Soil
Plants need air, sunlight, water, and soil to grow. The aim of this experiment is to assist students to find out whether plants can grow without soil. You can use coconut coir as your growing medium or moist cotton wool. Start the project by making six identical hydroponics containers and plants your seeds. Treat all the plants the same way, expose them to light, and keep them hydrated. Let the students observe and record data on the plant growth in the absence of soil.
Build a Circuit to Detect Ripe Produce
With this experiment, the students should determine whether an electromagnetic spectrum can detect if a fruit like tomatoes or strawberries is ripe and ready for consumption without waiting for color change. The necessary materials are fruits and electronic circuit components.
- First, the students should build a circuit and differentiate the difference in the light produced by the LED when connected to green and ripe produce.
- Then, use a potentiometer to control the voltage to each fruit.
- Finally, observe and record any changes, then draw a conclusion based on the observations.
Can Plants Stop Soil Erosion?
Students will conduct this experiment to find out the role plants play in controlling soil erosion. The required materials for this experiment include six bread pans, different types of soil, three with seeds and three without.
The experiment will take about three weeks as students wait for the seeds to germinate. A pair will be subjected to similar conditions, and students should observe the soil erosion. Each couple of bread pans faces exposure to different conditions contributing to soil erosion and simulations of rain. Students will make a conclusion depending on the type of soil and whether plants are helpful in the control of soil erosion.
Bottle Ecosystem
Students conduct the bottle ecosystem to determine whether they can make their ecosystem inside a bottle. The procedure is easy as all you have to do is place some sediments and soil at the bottom of the experiment jar, add some water, add a couple of plants like duckweed or water grass, a couple of water snails, then seal the bottle. The bottle will remain closed throughout the whole experiment. Students should record and observe as life unfolds inside a bottle.
