Plant Cell Structure Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main component of the cell wall in its secondary layer?

Cellulose (correct)

Lignin

Pectin

Hemicellulose

Which chemical property is NOT associated with cellulosic walls?

Gives a blue color with iodine and sulfuric acid

Stains magenta red with phloroglucin and hydrochloric acid (correct)

Gives blue color with chloro-Zinc-iodine

Dissolves in ammonical solution of copper oxide

What characterizes the tertiary wall of a cell?

Amorphous and pectin-rich

Thick and composed mainly of cellulose

Primarily made of lignin

Thin and highly refractive (correct)

Mucilaginous walls are primarily composed of which type of molecules?

Polysaccharides and uronic acid Signup and view all the answers

What type of wall is characterized by the presence of lignin?

Lignified walls Signup and view all the answers

Which of the following statements about the middle lamella is incorrect?

It is primarily composed of proteins. Signup and view all the answers

What coloration is observed when lignified walls are treated with phloroglucin and hydrochloric acid?

Magenta red Signup and view all the answers

Which of the following characteristics is NOT associated with the phylum Thallophyta?

Plants are differentiated into root, stem, and leaves Signup and view all the answers

Which of the following phyla does NOT belong to the division of Cryptogams?

Gymnospermae Signup and view all the answers

What distinguishes the phylum Gymnospermae from Angiospermae?

Ovules lie naked on the surface of sporophylls Signup and view all the answers

In phylum Bryophyta, what is true about the relationship between sporophyte and gametophyte?

Sporophyte is parasitic on gametophyte Signup and view all the answers

Which of the following is a characteristic of the phylum Pteridophyta?

Distinct alteration of generation occurs Signup and view all the answers

Which of the following statements about starch aggregates is correct?

Wheat starch has mostly simple aggregates, with a few compound aggregates. Signup and view all the answers

What unique characteristic does potato starch possess in terms of hilum appearance?

The hilum is eccentric and pointed. Signup and view all the answers

Which chemical test can confirm the presence of starch?

The blue color test with iodine solution. Signup and view all the answers

Which statement accurately describes the striation of wheat starch granules?

Wheat starch granules exhibit faint, concentric striations. Signup and view all the answers

How is maize starch primarily categorized in terms of shape and size?

Maize starch has a polyhedral shape and a small size. Signup and view all the answers

Which option correctly describes the uses of starch?

Starch is utilized for paper sizing and as a diluent in pharmaceuticals. Signup and view all the answers

Which of these is NOT a characteristic of rice starch?

Rice starch exhibits distinct concentric striation. Signup and view all the answers

What describes the shape of wheat starch granules as viewed from the side?

Wheat starch granules are oval and lenticular. Signup and view all the answers

Which type of aggregation is mostly present in potato starch?

It is composed of mostly simple aggregates with some semi-compound aggregates. Signup and view all the answers

Which type of stomatal structure is characterized by subsidiary cells having their long axes parallel to the osteole?

Paracytic or Rubiaceous Signup and view all the answers

Identify the mesophyll configuration that is asymmetric with only one palisade layer beneath the upper epidermis.

Dorsiventral Signup and view all the answers

In the context of leaf structure, where is the phloem located?

Towards the lower surface of the leaf Signup and view all the answers

What term describes the collective structure of sepals and petals when they resemble each other?

Perianth Signup and view all the answers

The flower's male organ, composed of stamens, is referred to as which of the following?

Androecium Signup and view all the answers

What describes a flower that is attached directly without a stem?

Sessile Signup and view all the answers

Which part of the flower is formed of modified leaves that are involved in the reproduction process?

Floral leaves Signup and view all the answers

Which type of mesophyll is characterized by cylindrical, columnar cells oriented perpendicularly to the epidermis?

Palisade Signup and view all the answers

What type of cortical tissue is primarily found in the midrib of leaves?

Both parenchyma and collenchyma Signup and view all the answers

What is the function of the nectar secreted by the nectaries in flowers?

Attract pollinators Signup and view all the answers

What is the role of interfascicular cambium in the secondary thickening of Dicotyledones?

It forms a continuous ring between the intrafascicular cambium. Signup and view all the answers

Which of the following accurately describes the primary roots?

They primarily serve as the main anchor for the plant. Signup and view all the answers

Which layer of a young root is responsible for producing root hairs?

Piliferous layer Signup and view all the answers

How does the formation of cork cambium relate to secondary thickening?

It helps protect outer layers from rupturing as the stem diameter increases. Signup and view all the answers

What characterizes the stele of a young root?

Enclosed vascular bundles without cambium. Signup and view all the answers

Which type of root arises directly from the stem?

Adventitious roots Signup and view all the answers

What occurs during the division of the interfascicular cambium?

It may give rise only to parenchyma, leaving bundles separate. Signup and view all the answers

In the structure of an old root, where does the cambium originate?

From parenchyma below the phloem. Signup and view all the answers

Which type of root is distinguished by its storage capacity due to swelling?

Storage roots Signup and view all the answers

What layer of the root serves as the innermost boundary of the cortex?

Endodermis Signup and view all the answers

Study Notes

Medicinal Plants - Lecture Notes

Medicinal plants are used to cure or prevent disease.
Their action is through chemicals called active constituents.
Plants can be annual, biennial, or perennial.
Annuals live for one year and die after producing flowers, fruits, and seeds.
Biennials live for two seasons.
Perennials live for more than two years.

The Cell and Cell Differentiation

A cell is the fundamental unit of a living organism (plants and animals).
It's composed of a cell wall, nucleus, cytoplasm, vacuoles (containing crystals and aleurone grains), mitochondria, Golgi bodies, lysosomes, and plastids.
A group of identical cells performing a specific function is called tissue.
The cell wall of mature cells consists of the middle lamella (intercellular substance), primary wall (cellulose and pectin), secondary wall (primarily cellulose with polysaccharides), and tertiary wall (thinner cellulose layer).
Modifications like lignin, suberin, and cutin can occur in the secondary and tertiary walls.

Cell Wall Properties

Cellulosic Walls: Mostly cellulose, possibly with hemicellulose and pectin (a polysaccharide composed of linear chains of glucose residue).
These walls stain blue with iodine and sulfuric acid.
They also stain blue with chloro-zinc-iodine.
Cellulosic walls don't react with aniline, phloroglucin, or HCl.
They dissolve in CuO in an ammonia solution.
Mucilaginous Walls: Certain cellulosic cell walls can be transformed into gums and mucilages.
These stain with ruthenium red, iodine sulfuric acid, or corallin soda.
Lignified Walls: Lignin is a strengthening material forming a complex polymer of phenylpropanoid.
Stain magenta red with phloroglucin and hydrochloric acid.
Suberized and Cutinized Walls: Suberin and cutin are mixtures of polymerized fatty acids and suberic acid.
Stain red with alkanna tincture and Sudan III.
Chitinous Walls: Chitin is a polysaccharide derivative found in insects and fungi.
Heated with 50% potash at 160-170°C, it's converted into chitosan, ammonia, and acids (acetic and oxalic).
Gives a deep violet coloration with iodine solution followed by dilute sulfuric acid.

Plant Tissues

Parenchyma: Is the fundamental or ground tissue with isodiametric or slightly elongated cells. Contains starch granules and calcium oxalate crystals.
Collenchyma: Is a living mechanical tissue with unevenly thickened, non-lignified walls, found in the angles (angular collenchyma) or tangential walls (lamellar collenchyma) of herbaceous stems, petioles, and leaf midribs.
Sclerenchyma: Thick-walled, dead, lignified cells primarily meant for support. Sclereids are short, isodiametric cells; Fibres are long, thin, and tapering.

Secretory Tissues

Found as isolated cells or rows with suberized walls.
Contents can include volatile oils, resins, gum-resin, mucilage, enzymes, tannins.
Secretory Cavities (Glands): Internal structures embedded in tissue, containing cavities where secretions (volatile oils, oleoresins, etc.) are secreted. Formed via:
- Schizogenous (splitting of cells to form a cavity).
- Schizolysigenous (first schizogenous, then cells break down).
- Lysigenous (cells break down to form a cavity).
Secretory Ducts: Tube-like structures, may extend through the entire plant (e.g., in leaves of Pinus). Develop schizogenously, lysigenously, or schizolysigenously (e.g., in Capaifera).
Laticiferous Structures: Tube-like cells containing latex (colorless, milky emulsion).

Primary Metabolites - Carbohydrates

Carbohydrates are organic compounds containing C, H, and O. Primary example is starch.
Starch: A polysaccharide (polymer of glucose) formed through photosynthesis. Plants absorb CO2 and water in presence of chlorophyll & sunlight. Starch molecules link together to form granules.
Amylose: inner layers of starch granules, soluble in water.
Amylopectin: outer layers of starch granules, insoluble in water.

Microscopical and Macroscopic Characters of Starch

Starch occurs as granules in various shapes (irregular, angular, oval).
Insoluble in cold water but forms a colloidal solution in boiling water.
Staine deep blue/violet with iodine.
Gelatinizes on heating with water thus swelling first then dissolving.

Proteins

Proteins are nitrogenous compounds composed of amino acids. Found in seeds as aleurone grains.
Aleurone Grains: Small solid protein particles often in seeds. Consist of: ground substance (soluble protein), crystalloid (albumin, insoluble protein), and globoids (containing globulin and calcium/magnesium hexaphosphoric acid).

Lipids

Lipids include fixed oils, fats, and waxes. Fixed oils are liquids while fats are solids. Waxes are esters.
Fixed oils and fats hydrolyze to form glycerol and soap with aqueous alkali Hydrolysis by aqueous caustic alkali forms soap and glycerol (specification).

Secondary Metabolites - Special Focus

Alkaloids: Naturally occurring, nitrogen-containing organic compounds often having marked effects on organisms and may be basic.
Glycosides: Organic compounds consisting of a sugar part (glycone) and a non-sugar part (aglycone).
Volatile Oils/Essential Oils: Volatile oils are often aromatic mixtures of hydrocarbons and oxygenated compounds.
Tannins: Water-soluble polyphenol compounds that bind to proteins (e.g., in tanning leather). Can be classified as hydrolysable (which are hydrolyzed with acids/enzymes) or condensed (not hydrolyzed).

Crystals of Calcium Oxalate

Calcium oxalate is a common plant component that may be of crystalline structures. They are insoluble and found in many diverse plant parts.
Forms: Includes acicular (needle shaped), prismatic, rosette, and cluster types (various shapes, orientations, and sizes).

The Stem

The stem is the main axis of the plant, generally above ground.
Functions: Support leaves and flowers, conduct water and minerals, and transport food.
Shapes: Cylindrical, angular, triangular, quadrangular.
Types: Herbaceous (soft), succulent (fleshy), woody (hard)
Branching types: Monopodial (main axis continues growing) Sympodial (apical bud stops growing, axillary buds develop into new branches.)

The Root

The root is the underground portion of the plant.
Functions: Absorbs water and minerals from the soil, anchors the plant, and stores food.
Types: Primary roots (main central root—e.g. tap root), Secondary roots (branches).
Adventitious roots (arise from non-root parts of the plant, e.g., stem).
Fibrous roots (a system of thin roots).

The Leaf

Leaves are flattened, lateral outgrowths from the stem usually bearing chlorophyll and serving for photosynthesis and transpiration.
Parts of the leaf: Lamina (blade—the flattened part), Petiole (stalk), and Base (connection of leaf to stem.)
Types: Simple (undissected leaf blade), Compound (blade dissected into leaflets)
Edges of leaves: can have distinct margins (e.g., entire, crenate, dentate, serrate).
Shape of leaf bases to tips include: ovate, obcordate, etc.
Types of venation: parallel, reticulate.
Surface characteristics: smooth, punctate, pubescent etc.

The Flower

Flowers are specialized structures on plants that facilitate reproduction.
Floral Parts: Receptacle (support structure), Calyx (sepals—often green), Corolla (petals—often colored), Androecium (male reproductive parts, stamens) Gynaecium (female reproductive parts, the pistil),
Types of Flowers: Complete (all four whorls), Incomplete (lacking one or more whorls), Regular (actinomorphic, can be divided into two symmetrical halves), Irregular (zygomorphic, division into symmetrical halves is only in one plane).

Inflorescence

Arrangement of flowers on the plant.
Two main branching types: Racemose (older flowers generally at the base of the axis or the central axis), Cymose (generally with older flowers at the apex and newer flowers lower down the stem). Capitula (a condensed inflorescence with sessile florets, surrounded by bracts).

Chromatography

Chromatography is a lab technique used for separating components of a mixture.
Main Phases: Stationary phase (a non-moving component, often solid or a liquid coating), Mobile phase (moving substance which may carry various compounds away).
Types: Thin layer chromatography (TLC) and Column chromatography, Gas Liquid Chromatography (GLC).

Crude drug considerations

Quality control is an important step in using plants for medicinal purposes.
Important stages for production: Cultivation, Collection, Drying, Packing, and Preserving.
The stage of maturity often influences the production and the presence of active substances.
Environmental Factors including soil health, and season are key to quality.
Various methods of collection; collection times; processing needs.

Evaluation of Crude Drugs

Examining crude drugs for identification using various methods (e.g., morphological, microscopic, chemical, biological, or physical characteristics).
Establishing quality control (checking for impurities and proper storage and handling techniques).
Ensuring that active constituents are present at proper levels. Aromatic quality; composition; structure; possible adulteration; purity considerations.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on plant cell structure and composition. This quiz covers components like the cell wall, middle lamella, and the differences between various plant phyla. Brush up on your understanding of mucilaginous walls and lignin characteristics in plant biology.