Study of Characteristics of Plant Specimens and Identification with Reasons

Introduction

Plants of the same species change in traits based on the location and individual plant, just as humans have unique faces and other physical characteristics that set them apart from other species.By looking in a reference book or reading a description, it is difficult to identify a specific plant. However, if we see the specimen in person and use a magnifying glass or microscope to check the plant's size or observe its characteristics, we will be able to identify it. By looking at archived specimens, we can see the morphological variances and identify the specimen.

Table of Contents

• Aim

• Apparatus Required

• Theory

• Procedure

• Observation

1. Classification

2. Diagnostic Features

3. Features

• Result

• Precautions

• Lab Manual Questions

• Viva Questions

• Practical Based Questions

• Summary

• Frequently Asked Questions

Aim

To identify and explore the morphology of various bacterial, fungal, and plant species.

Apparatus Required

1. Permanent Slides of Bacteria

2. Oscillatoria

3. Spirogyra

4. Rhizopus

5. Yeast

6. Liverwort

7. Preserved/Fresh Specimens of Mushroom

8. Lichens

9. Moss

10. Fern

11. Pine

12. One Monocotyledonous Plant(ex:maize plant)

13. One Dicotyledonous Plant(ex:sunflower)

Theory

The study of morphology is the examination of a species. Classification is also involved in the process of comparing an unidentified specimen to a described specimen and concluding that the two components are the same. Identification is a fundamental step in classification, and nomenclature is crucial to information retrieval.It involves a study of internal or external characteristics.

Procedure

1. Microscopic tools can be used to study microscopic creatures like bacteria, algae, and fungi. Write the characters after examining the permanent slides under a microscope.

2. The naked eye can be used to examine large-sized specimens.

3. Write the  features of identification.

4. Compare the features and the observations.

Observations

The specimens are observed and their features are noted.

Bacteria

Classification

Kingdom - Monera

Class - Eubacteria

Features

• Bacteria are unicellular organisms 

• Small size.

• Organelles with membranes, such as mitochondria, nuclei, and golgi bodies, are absent.

• Mesosomes(They are recognized as an integral part of the cell membrane that  are found in both prokaryotic and eukaryotic cells and support the production of cell walls and DNA replication) are visible.

• Flagella is present for locomotion(movement).

Bacteria

Oscillatoria

Classification

Kingdom - Monera

Division - Cyanobacteria

Class - Cyanophyceae

Diagnostic Features

• Each row of cells forming Oscillatoria create unbranched filaments. 

• The cells are cylindrical but broader than longer. 

• With the exception of the apical cell, which is convex at the top, all filament cells are similar.

Features

• It is a blue-green algae.

• Thallus is multicellular, unbranched, and filamentous.

• The cells are stacked one on top of the other.

• It has a cell wall and uses photosynthesis.

• The filament may have some dead cells that are visible as empty gaps.

• Fresh filament specimens exhibit oscillatory movements, therefore the name Oscillatoria.

Oscillatoria

Spirogyra

Classification

 Kingdom - Plantae

 Division - Thallophyta

 Class - Chlorophyceae

Diagnostic Features

• It is green filamentous algae.

• Each filament is unbranched, and the cytoplasm holds one or more ribbon-shaped spirally arranged chloroplasts.

 Features

• Spirogyra is free floating blue green algae.

• It has no branches and feels slimy to the touch.

• The filament is made up of numerous long, cylindrical cells arranged in a single row, one above the other.

• Spirogyra is useful for human consumption.

• Each cell contains a single, sizable vacuole.

Spirogyra

Rhizopus

Classification

Kingdom - Fungi 

Division - Eumycota

Class - Zygomycetes

Diagnostic Features

• They are distinguished by a body of branching mycelium made up of three different hyphae kinds.

• The tips of the black sporangia are rounded.

Features

• Rhizopus have mycelia(branching body).

• They mainly feed on dead matter.

• Well developed rhizoids are present.

• It is a cosmopolitan fungi.

• The hyphae are of three types-stolons,rhizoids and sporangiophores.

Rhizopus

Agaricus (Mushroom)

Classification

Kingdom  - Fungi 

Division   - Eumycota 

Class        - Basidiomycetes

Diagnostic Features

• Agaricus resembles an umbrella.

• On the lower side of the pileus, there are gills.

Features

• Mushroom is the fruiting body of Agaricus

• The fungus, a saprophyte, lives in humus-rich soil .

• The thallus is made up of a mass of dense, colourless hyphae that is deep.

• Two components of a mature mushroom can be identified.

• A pileus-like structure attached ventrally to the centre of an upright stalk or stipe made up of a mass of vertically oriented hyphae.

• An annulus, which resembles a collar and is part of the young basidiocarp's covering, can be seen at the base of the stipe.

Agaricus

Yeast

Classification

Kingdom - Fungi 

Division - Eumycota 

Class - Saccharomycetes

Diagnostic Features

• Unicellular

• Nuclear envelope is present.

Features

• Oval or spherical in shape, cells have no colour.

• Cells create chains of buds that aid in reproduction 

• There is one vacuole per cell.

• Each cell has a single nucleus.

• They reproduce asexually by budding and sexually by spore formation.

Yeast

Liverwort

Classification

Kingdom - Plantae 

Division  -Bryophyta 

Class - Hepaticopsida 

Diagnostic Features

The sporophyte is immersed in a flat thallus that has repetitive dichotomous branching.

Features

• The thallus is a flat, dorsiventrally oriented thalloid structure that develops on the substratum(surface) of the soil.

• The dorsal surface of the thallus is home to tiny gemma cups, which resemble little cups. They contain the gemmae, or vegetative propagules.

• Rhizoids of two types—tuberculate and smooth-walled—that are colourless, unicellular, and present on the ventral side of the thallus are present. Through their capillary function, rhizoids aid in binding and water absorption.

Liverwort

Moss

Classification

Kingdom - Plantae 

Division - Bryophyta 

Class - Musci/Bryopsida

Diagnostic Features

• Rhizoids are long, colourless.

• Rhizoid branched and separated obliquely.

Features

• The Funaria thallus is made up of a thin, erect "stem" that bears tiny, oval and leaf-like structures without midribs .

• The green leaves are arranged in a spiral pattern on the stem-like section.

• A group of filaments anchor the thallus to the substratum rhizoids.

• Rhizoids are septate, long, colourless, and entwined.

• Separate branches of the body carry the reproductive organ.

Moss

Fern

Classification

Kingdom - Plantae 

Division - Pteridophyta

Class - Filicopsida

Diagnostic Features

• Furcate venation on the pinnate leaves.

• Fresh leaves have rementa.

Features

• Fern has an underground, slant developing rhizome.

• A cluster of adventitious roots and scale leaves are present on the short, thick rhizome, which is also covered in the remains of leaf bases.

• The aerial shoot is made up of several large compound leaves, or fronds.

• From a bud, a complex leaf develops. The circinate venation of the juvenile leaf. The petiole contains a thick covering of brown hair-like structures called ramenta, and the leaf is rolled downward from the apex, much like a watch spring.

• Long, complex leaves with leaflets grouped on either side of the midrib, or "rachis," measure up to 1.0 to 1.5 metres in length.

• The petiole's expanded portion is called the rachis.

• When young, the petiole is lengthy, cylindrical, and hair-covered.

Fern

Pine

Classification

Kingdom - Plantae 

Division  - Spermatophyte

Class  -Gymnospermae

Diagnostic Features

• perennial evergreen tree seeds are naked.

• Hard and woody stem

Features

• Pinus is a tall, conical tree.

• There are two types of branches: (a) branches with limitless development, and (b) branches with restricted expansion.

• Both varieties of branches have an abundance of membranous, scaly, brown leaves.

• Scale leaf axils bear branches with restricted development. They have a cluster of long, needle-like leaves and are 2–3 cm long.

• The green leaves that resemble needles are known as acicular leaves.

• The dwarf branch is referred to as a spur shoot because of its needles.

•  In the same plant, both the male and female cones bear reproductive organs.

Pine

Monocotyledonous Plant

Classification

Kingdom - Plantae 

Division -Angiosperm

Class -Monocotyledonae

Diagnostic Features

• Flowers are trimerous

• Seeds are enclosed in fruits

Features

• Differentiated plant body with roots, stems, and leaves .

• Fibrous root system 

• Simple or complex leaves with parallel venation.

• Ovules located within the carpels.

• A seed has a single cotyledon.

• For instance, paddy, sugarcane, wheat, and maize.

Monocotyledon root

Dicotyledonous Plant

Classification

Kingdom - Plantae 

Division - Angiosperm

Class - Dicotyledonae

Diagnostic Features

• Tap root system

• Embryo has two cotyledons.

Features

• Taproot system .

• Leaves with reticulate venation, either simple or compound.

• Tetramerous or pentamerous flowers that can grow singly or in groups to create inflorescences.

• Stamens and carpels are reproductive organs. Ovules are located within the carpels.

• The cotyledons in seeds are two.

• Example: Ground nut, lady's finger, pea, hibiscus, and gramm.

Dicot stem

Lichens

Classification

Kingdom-Fungi

Division -.Thallophyta

Diagnostic Features

Lichens have a body known as a thallus, an outside layer of fungi called a cortex, and an interior layer of fungi known as a medulla.

Features

• An interaction between an alga and a fungus results in the formation of lichens.

• Lichens are a fantastic way to measure the quality of the air.

• Lichens can develop on many different surfaces, including rocks, trees, buildings, and soil.

• The most frequent algal partners are members of the Chlorophyta or Cyanophyceae family of blue-green bacteria.

Lichen

Results

Thus the specimens are identified and their features are noted.

Precautions

• Do not take out the specimens 

• Handle the specimens and model carefully.

• Do not write or move pen on the specimens

Lab Manual Questions

1. Why does the earthworm belong to the phylum Annelida?Give one reason.

Ans: They exhibit bilateral symmetry coelomate, triploblastic, and metamerically segmented. So they belong to the phylum annelida.

2. An unlabelled slide shows filamentous structures with linearly arranged cells and blank spaces occurring intermittently.Name the specimen.

Ans: The specimen with filamentous structures with linearly arranged cells and blank spaces occurring intermittently is Oscillatoria.

3. What type of leaves are found in ferns?

Ans: Ferns' leaves are frequently referred to as fronds.Fronds consist of a petiole and a leafy blade.

4. Given only flowers of some plants, how would you classify them as monocots and dicots?

Ans: Monocot flowers have a number of parts that is divisible by three.Dicot flowers have parts that are multiple of four or five.

Viva Questions

1. What is another name of Rhizopus?

Ans: Another name of Rhizopus is bread mould.

2. Where is Oscillatoria found?

Ans: In the shallow water of lakes, ponds, ditches, and slowly moving rivers, Oscillatoria can be found.

3. Reproduction of Spirogyra takes place by which method?

Ans: Spirogyra reproduces through fragmentation, which includes cutting the filaments into smaller pieces.

4. Example of a unicellular eukaryotic organism?

Ans: The examples of unicellular eukaryotes are Yeasts and algae.

5. Give examples of yeast?

Ans: Examples of yeast are Saccharomyces cerevisiae, genus Cryptococcus.

6. What do you mean by liverworts?

Ans: A liverwort is a spore-producing, flowerless plant that produces its spores in tiny capsules.

7. What is the main difference between mosses and liverworts?

Ans: Mosses are made up of tiny, leafy arrangements that have a straightforward structure. Liverworts feature stem-attached thallus arrangements that resemble green leaves.

8. Which group does the fern plant belong to?

Ans: Fern belongs to the phylum pteridophyta.

9. Pine trees belong to which plant group?

Ans: Pine trees belong to gymnosperms.

10. What are lichens?

Ans: Lichens are a symbiotic association between an alga and fungus.

Practical Based Questions

1. Yeast and mushroom are different from spirogyra because they 

1. Cannot carry out photosynthesis

2. Lack cellulosic cell wall

3. Reproduce by sexual methods

4. Are terrestrial as well as aquatic

Ans: A. Cannot carry out photosynthesis

2. Vegetative reproduction in lichens takes place by

1. Isidia

2. Soredia

3. Fragmentation

4. All the above

Ans: D. All the above

3. Chloroplast in spirogyra is

1. Spirally arranged and ribbon shaped with pyrenoids

2. Spirally arranged

3. Circular

4. Cup shaped

Ans: A. Spirally arranged and ribbon shaped with pyrenoids

4. Needle shaped structure in pinus plant is

1. Leaf

2. Shoot

3. Stem

4. Reproductive part

Ans: A. Leaf

5. Which of the characters is an identifying feature of gymnosperms?

1. Naked seeds

2. Rhizoids present

3. Chlorophyll present

4. Does not possess vascular bundle

Ans: A. Naked seeds

6. Mosses are

1. Monoecious

2. Dioecious

3. Both a and b

4. None of these

Ans: A. Monoecious

7. Funaria differs from Dryopteris in

1. Bearing seeds

2. Having vascular bundle

3. Having a dependent sporophyte

4. Having an independent sporophyte

Ans: D. Having an independent sporophyte

8. Protein body associated with storage of starch grains in spirogyra is called

1. Leucoplast

2. Amyloplast

3. Pyrenoid

4. Chloroplast

Ans: C. Pyrenoid

9. While locating the stem of fern, the students find that it is

1. Underground rhizome

2. Coiled like spring

3. Totally absent

4. Branched and filamentous

Ans: A. Underground rhizome

10. The name cyanobacteria refers to

1. Bacteria

2. Blue green algae

3. Yeast

4. Fungi

Ans: B. Blue green algae

Summary

The specimens/models/slides are identified with their morphological and diagnostic features.Identification of specimens is the important step.