Introduction
In this experiment, we will find some of the parts of plants and animal tissues through a microscope.
Experiment A
Aim
To describe parenchyma and sclerenchyma tissues in plants through prepared slides and related diagrams.
Requirements
1. Parenchyma,
2. Collenchyma,
3. Sclerenchyma,
4. Compound microscope.
Theory
Tissues are a group of cells that perform a particular activity together. The parts of that include-
Procedure
Step 1: Observe all the prepared slides of plant tissues one after another.
Step 2: Focus the slide at low power and then at high power.
Step 3: Observe all the characters under the microscope and the diagram in your notebook.
Observation
A. Parenchyma
1. Parenchyma tissue cells are isodiametric.
2. Intercellular space between the cells is observed.
3. Parenchymatous cells have a large vacuole present at the centre.
4. These cells contain peripheral cytoplasm and a nucleus.
5. They are generally present in the bark, leaves, and soft parts of plants.
6. The important functions of these cells are photosynthesis, storage, growth, etc.
B. Collenchyma
1. These cells are elongated or oval-shaped.
2. Every cell has a large vacuole, cytoplasm, and a well-developed nucleus.
3. At the corners of all these cells. They present a thickening that is made up of cellulose and pectin.
4. There is an absence of intracellular spaces.
5. These cells are generally present below the epidermis in leaves, petiole, and stems.
6. The main function of this collenchyma cell is to give mechanical strength.
C. Sclerenchyma
1. The cells of this tissue are dead and have highly thickened walls.
2. This thickening contains lignin.
3. Sclerenchyma cells are of two types:
- Fibres that are elongated cells with taperings end.
- Stone cells are also known as sclereids, are isodiametric and have narrow cavities.
4. These cells have pits that connect adjacent cells.
5. These cells provide mechanical strength to the plants.
Precautions
1. Use a microscope carefully.
2. First, focus on lower power than higher power.
Experiment B
Aim
To identify muscle fibre and nerve cells in animals from the prepared slides and draw the labelled diagrams.
Requirements
1. Prepare slides of non-striated,
2. Striated and cardiac muscle fibres and nerve cells,
3. Compound microscope.
Theory
Animal tissues are of four types;
1. Epithelial tissues,
2. Connective tissues,
3. Muscular tissues,
4. Nervous tissues.
Procedure
Step 1: Clean the microscope thoroughly and adjust its lightly.
Step 2: Put the prepared slide under the microscope and then focus it at the lower power and then at the higher power.
Step 3: Draw the diagram of the observed tissue.
Observation
A. Skeletal Muscle
1. This muscle is also known as striped muscle or striated muscle.
2. These are cylindrical, elongated, and enclosed in a membrane.
3. These cells are multinucleated.
4. Due to the presence of light and dark bands, it gets the appearance of striped.
5. These muscles are present in the skeleton of the body,
6. These muscles are voluntary.
B. Smooth Muscles
1. These muscles are also known as unstriped or non-striated muscles.
2. These are spindle shape cells.
3. Nucleus is present in the centre.
4. These muscle does not show light and dark bands.
5. Their nature is involuntary.
6. They are mainly found in blood vessels and alimentary canals.
C. Cardiac Muscles
1. These muscles are branched and elongated.
2. Only one nucleus is present in it.
3. They show light and dark bands.
4. These muscles are involuntary.
5. They are responsible for the relaxation and rhythmic contraction of the heart.
6. They are present in the walls of the heart.
D. Nerve Cells
1. These cells are comprised of a cyton or cell body.
2. It has only one nucleus and cytoplasm.
3. Dendrons are the small cytoplasmic projection that arises through cyton. They are divided further into dendrites.
4. Axons are the long cytoplasmic projection arising from the cell body.
5. Myelinated nerve fibres are the myelin sheath that is present over the axon in some nerve fibres.
6. Non-myelinated fibre is the absence of myelin sheath over the axon.
7. Nodes of Ranvier are the gap between the myelin sheath.
8. These cells help in the conduction of cells.
Precautions
1. Use the microscope with the utmost care.
2. First, focus on lower power than higher power.
Result
We have successfully observed the plants and animal tissues under the microscope.
Viva Questions With Answers
Q.1 What do you mean by meristematic tissues?
ANS. Those tissues which could retain their property even after division are known as meristematic tissues.
Q.2 What do you mean by permanent tissues?
ANS. Those tissues which can not divide themselves further are known as permanent tissues.
Q.3 Name the types of plant tissues?
ANS. Meristematic tissues and permanent tissues.
Q.4 Name the type of permanent tissue?
ANS. Parenchyma, collenchyma, and sclerenchyma.
Q.4 What is the function of parenchyma tissue?
ANS. The important functions of these cells are photosynthesis, storage, growth, etc.
Q.5 What is the function of collenchyma tissue?
ANS. The main function of this collenchyma cell is to give mechanical strength.
Q.6 What is the function of sclerenchyma tissue?
ANS. These cells provide mechanical strength to the plants.
Q.7 What do you mean by simple tissues?
ANS. These tissues are made up of the same type of cells, performing similar functions.
Q.8 What do you mean by complex tissues?
ANS. These tissues are composed of different types of cells performing activities.
Q.9 Name the tissue which is dead at maturity?
ANS. Sclerenchyma
Q.10 Name the composition of thickening of collenchyma cells?
ANS. Pectin and cellulose
Q.11 What was the aim of our experiment?
ANS. To observe some parts of plants and animal tissues through a microscope
Saquib Siddiqui is a Mechanical Engineer and a content creator. He has special interest in science experiments and teaches the same to school and college students. He is also a technical lead at RUDE LABS PVT. LTD.
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