AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 8th Lesson Taxonomy of Angiosperms Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 8th Lesson Taxonomy of Angiosperms

Very Short Answer Questions

Question 1.
What is ‘Omega Taxonomy’?
Answer:
Omega Taxonomy is the Taxonomy based on information from other branches i.e., Embryology, Cytology, Palynology, Phytochemistry, Serology etc., along with Morphological characters.

Question 2.
What is Natural system of plant classification? Name the scientists who followed it.
Answer:
Plants are classified on the basis of all possible Morphological characters is called Natural system of classification. It was proposed by ‘Bentham’ and ‘Hooker’.

Question 3.
Explain the scope and significance of ‘Numerical Taxonomy’.
Answer:
Numerical Taxonomy is a branch of taxonomy that use mathematical methods to evaluate observable differences and similarities between taxonomic groups. In this, number and codes are assigned to all the characters and the data are then processed. Each character is given equal importance and at the same time hundreds of charactes can be considered.

Question 4.
What is geocarpy? Name the plant which exhibits this phenomenon.
Answer:
Geocarpy is the development of fruits inside the soil. It is seen in Arachis (ground nut).

Question 5.
Name the type of pollination mechanism found in members of Fabaceae.
Answer:
‘Piston Mechanism’.

AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Question 6.
Write the floral formula of solanum plant.
Answer:
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 1

Question 7.
Give the technical description of ovary in solanum nigrum.
Answer:
Bicarpellarly, Syncarpous, bilocular,superior ovary with many ovules on swollen axile placentation. Carpels are arranged obliquely at 45°.

Question 8.
Give the technical description of anther of Allium cepa.
Answer:
In Allium cepa. Anthers are dithecs, basifixed, Introrse and dehisce longitudinally.

Short Answer Type Questions

Question 1.
Write a brief note on semi technical description of a typical flowering plant.
Answer:
The plant is described beginning with its habit, habitat, vegetative characters (root, stem, leaves) and floral characters (inflorescence, flower and its parts) followed by fruit. Then floral diagram and a floral formula are presented. In floral formula, Br stands for bracteate (bracts are present), Ebr stands for ebracteate (bracts are absent). Brl stands for bracteolate (bracteoles are present), Ebrl stands for ebracteolates
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 2

Floral formula also indicates the number of free or united (within brackets) numbers Of the each whorl and also show cohesion or adhesion of stamens. Floral diagram provides information about the number of parts of a flower, their arrangement and the relation they have with one another. The mother axis represents the posterior side of the flower indicates as a dot or circle at the top of the floral diagram. K, C, A and G are drawn in successive whorls. The bract represents the anterior side of the flower and is indicated at the bottom of the floral diagram.

Question 2.
Describe the non-essential floral parts of plants belonging to Fabaceae.
Answer:
In Fabaceae, non-essential floral parts are Calyx and Corolla.

Calyx :
Sepals 5, gamosepalous, imbricate aestivation, odd sepal anterior.

Corolla :
Petals 5, polypetalous, papilionaceous type consists of a large posterior petal (standard) two laterals (wings). Two anterior fused petals (keel) enclosing essential organs. They show vexillary/descendingly imbricate aestivation.

Question 3.
Give an account of floral diagram.
Answer:
A floral diagram representing the number of parts of flower, the structure, arrangement, aestivation, cohesion and adhesion of stamens and position with respect to mother axis. The mother axis represents the posterior side of the flower and is indicated as dot at the top of the floral diagram. K, C, A, G are drawn in successive whorls. Calyx being the outermost and the gynoecium being the centre represented by T.S. of ovary. The bract represents the anterior side of the flower and is indicated at the bottom of the floral diagram.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 3

Question 4.
Describe the essential floral parts of plants belonging to Lilliaceae.
Answer:
The essential floral parts of Lilliaceae are Androecium and Gynoecium.
Androecium :
Six stamens in two whorls, free or Epipyllous, anthers are Dithecus Basifixed, Introrse and dehisce longitudinally.

Gynoecium :
Tricarpellary, Syncarpous, trilocular superior ovary with many ovules on axile placentation. Style is terminal and stigma is trifid and capitate.

Question 5.
Write a brief account on the class of Dicotyledanae of Bentham and Hooker’s classification.
Answer:
In Bentham and Hookers classification, the class Dicotyledonae was divided into three sub classes namely Polypetalae, Gamopetalae and Monochlamydae. Polypetalae, sub class is divided into three series namely Thalamiflorae (6 orders), disciflorae (4 orders) and Calyciflorae (5 orders). Gamopetalae, sub class is divided into three series namely Inferae (3 orders), Heteromerae (3 orders) and Bicarpellatae (4 orders). Monochlamydae was divided into eight series.

AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Question 6.
Explain floral formula.
Answer:
The floral formula is represented by some symbols of floral parts. In it, Br stands for bracteate (bracts are present), Ebr stands for ebracteate, (bracts are absent), Brl stands for bracteolate (bracteoles are present).

Ebrl stands for ebracteolates (bracteoles are absent).
⊕ stands for actinomorphic flower,
% stands for zygomorphic flower.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 4
ovary. Floral formula also indicates the number of free or united members of the corresponding whorls. It also shows cohesion or adhesion of stamens.

Question 7.
Give economic importance of plants belonging to Fabaceae.
Answer:
Economic importance :

  1. Pulses like red gram (Cajanus cajan), black gram (Phaseolus mungo), green gram (Phaseolus aureus), Bengal gram (Cicer aritetinum) are a rich source of proteins.
  2. Pods of Dolichos, Glycine are used as vegetables.
  3. Seeds of Pisurn and Arachis are edible.
  4. Groundnut oil from Arachis hypogea seeds and soyabean oil from seeds of Glycine max are used in cooking.
  5. The oil cake from Arachis hypogea is used as fodder.
  6. The oil from the seeds of Derris indica is used in the making of medicines.
  7. Goldsmiths use the seeds of Abrus precatorius for weighting.
  8. Several crops are used in crop rotation due to their nitrogen fixing ability.
  9. Seeds of Trigonella are used as condiment and medicine. The leaves are used as vegetable.
  10. Sesbania andTephrosia are used as green manure.
  11. Crotalaria and Phaseolus are used as fodder.
  12. Fibre from Crotalaria is used in making ropes.
  13. Indigofera yields blue dye, which is used as a fabric whitener.
  14. Wood from pterocarpus is used for making musical instruments.
  15. Wood from Da/zberg/a is used for making furniture.

Question 8.
Describe the essential organs of Solanaceae.
Answer:
Androecium :
There are five epipetalous stamens alternating witht he petals and are free. Anthers are dithecous, basifixed and introse. The dehiscence may be longitudinal (Datura) or Porous (So/anum).

Gynoecium :
The ovary is superior, bicarpellary and syncarpous. It is oblique in position and anterior carpel to the left at an angle of 45°. Usually bilocular occassionally unilocular (Capsicum). There are numerous anatropous ovules arranged on axile placeritation on swollen placenta. The style is terminal and stigma is capitate,

Long Answer type Questions

Question 1.
Describe the characteristics of plants belonging to Fabaceae.
Answer:
VEGETATIVE CHARACTERISTICS :
Habitat:
Most of the members of this family are mesophytes.

Habit :
The plants are annual herbs, some are shrubs, some others are trees. Some are weak stemmed that climb as twiners (Dolichos) or with tendrils (Pisum).

Root System :
It is tap root system. The roots bear root nodules in which the symbiotic nitrogen fixing bacteria. Rhizobia are present.

Stem :
It is aerial, erect, herbaceous or woody. In some plants stem is weak and prostrate or twinner (Dolichos) or a tendril Climber (Pisum, Lathyrus).

Leaf:
Leaves are cauline, alternate, stipulate, petiolate and dorsiventral. The leaf base is pulvinous. They are simple or pinnately compound, the entire leaf except stipules in Lathyrus and terminal leaflets in Pisum are modified into tendrils. In ulex, the leaflets are modified into spines. Venation is Reticulate.

Floral characteristics :
Inflorescence :
It is usually an axillary or terminal raceme (Crotalaria).

Flower :
Flowers are bracteate, bracteoles may be present or absent, pedicellate, complete, zygomorphic, bisexual, pentamerous and perigynous. The thalamus is cup shaped.

Calyx :
There are five sepals which are fused. The aestivation is valvate. The odd sepal is anterior in position.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 5

Corolla :
It consists of five petals which are free (Polypetalous). The corolla is papilionaceous. The posterior petal is largest and is called ‘Standard petal or Vexillum’. The two lateral petals are called ‘Wings or Alae’. The two boat shaped petals are called ‘Keel or Carina’. These are fused and encloses the essential organs. The aestivation is ‘descendingly imbricate’.

Androecium :
It consists of 10 stamens occasionally there may be only 9 stamens (Abrus, Datbargis). Usually the filaments of the stamens unite to form two bundles of 9 + 1 (Diadelphous) as in Dofichos, Tephrosia, Pisum etc., or a single bundle (Monadelphous) as in Crotalaria, Arachis etc. Anthers are dithecous, introrse and dehisce longitudinally.

Gynoecium :
It consists of monocarpellary, unilocular, half-inferior ovary. Usually many pendulous ovules are arranged in two vertical rows on marginal placentation. Style is long and curved at the apex. Stigma is capitate.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 6

Pollination :
As flowers are protandrous, usually cross pollination occurs. In lathyrus andpisum, there is self pollination.

Fruit:
Mostly the fruit is a legume or pod (Pisum, Cajanus, Dolichos). In pterocarpus and Dalbergia it is a samara while in Arachis the pods are indehiscent and geocarpic.

Seed :
It is non-endospermic and dicotyledonous. The cotyledons store proteins in large quantities.

AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Question 2.
Write about the key characteristics of Solanaceae.
Answer:
VEGETATIVE CHARACTERS :

Habitat :
These plants are mostly mesophytes. A few are xerophytes. (Solarium surattense).

Habit :
Mostly annual or perennial herbs. Some are shrubs (Oestrum sps).

Root system :
Tap root system.

Stem :
It is aerial, erect and mostly herbaceous. Stem is an underground tuber in Solanum tuberosum (potato). Bicollateral vascular bundles are present in the stem.

Leaf :
Leaves are exstipulate, petiolate and show alternate phyllotaxy. They are usually or pinnately lobed. Venation is reticulate.

FLORAL CHARACTERS :
Inflorescence :
It is usually cymose type. It may be terminal or axillary in position. In some species of Solarium, it is an axillary. In Datura, it is solitary and terminal, panicle in tobacco.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 7

Flower :
The flowers are bracteate or ebracteate, ebracteolate, pedicellate, actinomorphic, complete, bisexual, pentamerous and hypogynous.

Calyx :
It consists of 5 speals which are fused (gamosepalous) and persistent (Capsicum, Solatium). The aestivation is valvate.

Corolla :
The corolla consists of 5 petals and is gamopetalous. The aestivation is valvate or twisted. (Datura)

Androecium :
There are five epipetalous stamens alternating with the petals and are free. Anthers are dithecous, basifixed and introse. The dehiscence may be longitudinal (Datura) or porous (So/anum).

Gynoecium :
The ovary is superior, bicarpellary and syncarpous. It is oblique in position due to the tilting of posterior carpel to the right and anterior carpel to the left at an angle of 45°. Usually bilocular occasionally unilocular (Capsicum). There are numerous anatropous ovules arranged on axile placentation on swollen placenta. The style is terminal and stigma is capitate.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 8

Pollination :
Flowers are usually protandrous. Some species of So/anum are protogynous. Cross pollination through insects (entomophily) is common.

Fruit:
The fruit is mostly berry (Capsicum, Solatium, Lycopersicon, Physalis etc.). It is septifragal capsule in Datura and Nicotiana.

Seeds :
The seeds are endospermic and dicotyledonous.

Question 3.
Give an account of the family Liliaceae.
Answer:
VEGETATIVE CHARACTERS :
Habitat:
Plants may be mesophytes (Allium, Ulium) as well as xerophytes (Asparagus, Ruscus, Aloe) are found in this family.

Habit :
Plants are mostly perennial herbs. In some plants like Dracaena, Yucca, Aloe etc., Shrubs or trees are also found. Few are climbers (Gloriosa, Smilax).

Root system :
It is adventitious root system. In Asparagus fasciculated tuberous roots are present.

Stem :
In majority of the species the stem is underground and perennial. It may be a bulb (Sci/la, Allium, Ulium), a Rhizome (Gloriosa) or a corm (Colchicum). The aerial stem is weak in tendril climbers like Gloriosa, Smilax etc. Stem is aerial and shows anomalous secondary growth in Dracaena and Yucca. Branches are modified into cladophyllus (Asperagus, Ruscus).

Leaf:
The leaves may be radical (Allium; Ulium) or cauline (Smilax, Gloriosa). Alternat phyllotaxy is common. Leaves are petiolate, simple stipulate or exstipulate.Venation is usually parallel, but exceptionally reticulate in Smilax. Leaves are succulent in yucca and Aloe.

FLORAL CHARACTERS :

Inflorescence : Solitary cyme or umbel or raceme.
Flower :
The flowrs are usually bracteate, ebracteolate, pedicellate, actinomorphic, complete. Bisexual, homochlamydeous, trimerous and hypogynous. Exceptionally flowers are unisexual in Smilax and Ruscus.

Perianth :
It consists of six tepals arranged in two whorls of three each. The odd tepal is anterior in position. The aestivation is valvate.

Androecium :
Stamens are six, arranged intwo whorls of three each. Epiphyllous (Asparagus). Anthers are dithecous, basifixed, introrse and dehiscence is longitudinal.

Gynoecium :
It is tricarpellary and syncarpous. The oary is superior and trilocular with several anatropous ovules on axile placentation. The style is terminal and stigma is trifid and capitate.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 9

Pollination :
It is of entomophilous type. Flowers may be protandrous (Allium) or protogynous (Colchicum) in Glorisa flowers show herkogamy.

Fruit:
It may be a berry (Asparagusr, Smilax) or loculicidal capsule (Lilium) or septicidal capsule (Gloriosa).

Seed :
It is endospermic with straight or sometimes curved embryo and monocotyledonous. Polyembryony is seen in some memebrs (Allium).
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 10

Question 4.
Write the characteristics of plants that are necessary for classification. Describe them in brief.
Answer:
VEGETATIVE CHARACTERS :
Habit:
Herbs (Plants grow to a height of 1 – 3 feet)

Shrubs (Plants which grow in the form of a bush)
Trees (Plants with erect, woody branched or unbranched)
Habitat : Hydrophytes : (Plants which grow in water)
Mesophytes : (Plants which grow in Moderate climatic conditions)
Xerophytes : (Plants which grow in dry areas)
Root system : Taproot system : (The main root called Tap root, which inturn forms lateral roots and Root lets).
Ex : Dicots.
Fibrous Root system : (Cluster of roots which arise from the base of the stem)
Ex : Monocots.

Stem :
Aerial (which grows aerially) or underground (which grows into the soil), erect (Stands in upright position) or creeping (which grows on the soil Horizontally) Tendril climbers (Climbing with the help of Tendrils) Stragglers (Woody plants that climb up with the help of Hooks or thorns) Lianes (Large woody perennial twinners) Branched (Stem with Branches) or unbranched (stem without Branches) green or Brown or black in colour.

Leaf : Leaf Base :
Pulvinous (Swollen) or sheathing (Broad and surround the stem as envelope).
Stipules : Stipulate (Leaf with stipules)
Exstipulate (Leaf without stipules).

Petiole : Petiolate (Leaf with petiole)
Sessile (Leaf without petiole).

Lamina :
Shape – Ovate (oval) or Linear (Long and slightly Broader) Reniform (Kidney shaped) Cordate (Heart Shaped) Centric (hollow).

Venation :
Reticulate (Midrib, Laterial veins and veinlats are arranged in the form of net like).

Parallel :
(Mid rib produce lateral veins and veinlets arranged parallely).

Kind :
Simple (Leaf with undivided Lamina) .
Compound (Lamina is divided into leaflets).

Phyllotaxy :
Alternate (only one leaf arises at a node)
Opposite (Two leaves arises at each node)
Whorled (More than 2 leaves arises at each node).

FLORAL CHARACTERS :
Inflorescence : Racemose (Peduncle is long)
Cymose (Peduncle is short) ‘
Special (Verticillester or Hypanthodium or Cyathium).

Flower : Bracteate (The flower with Bracts)
Ebracteate (The flower without Bracts)
Bracteolate (The flower with Bracteoles)
Ebracteolate (The flower without Bracteoles)
Pedicillate (The flower with Pedicel)
Sessile (The flower without Pedicel)
Complete (The flower with all four floral parts)
Incomplete (The flower without an any one of the floral parts).

Arrangement of Floral parts Acyclic : The floral parts are spirally arranged.

Cyclic : The floral parts are arranged in whorls.
Hemicyclic : K & C are in whorls and A & G are in spiral Manner).
Sex : Bisexual : The flower with both sex organs.
Unisexual: The flower with any one of the sex organs.

Gynoecium Position : Hypogynous : The flower with superior ovary.
Epigynous : The flower with Inferior ovary.
Perigynous : The flower with Half superior ovary.
Merosity : Trimerous : Three parts in each whorl
Tetramerous : Four parts in each whorl.
Pentamerous : Five parts in each whorl.

Symmetry :
Actinomorphic: A flower can be cut into two equal halves in any vertical plane.

Zygmorphic :
A flower can be cut into two equal halves in one vertical plane.

Calyx :
Number of sepals 3 or 4 or 5, polysepalous (free) or gamo$epalous (fused) valvate (arranged in a whorl) or twristed Aestivation (arranged in one whole with one margin Inside and one margin outside). Imbricate Aestivation (arranged with overlapping pattern).

Corolla :
Number of petals, polypetalous (free) or gamopetalous (fused), Aestivation (valvate or Twisted or Imbricate).

Androecium :
Number of stamens 4 or 5 or 10 or many.
Monadelphous : All are in one Bundle
Diadelphous : All are in two Bundles
Polyadelphous : All are in. more than two Bundles.
dithrecous : Anther with two Theca.
Monothecous : Anther with one Theca.
Basifixed ; Filament gets attached to the Base of the Anther.
Dorsifixed : Filament gets attached to the Dorsal side of the anther.

Dehiscence : Longitudinal (Breaks vertically)
Transverse (Breaks Transversely)
Porous (Pollengrains are released through Apical pore).

Gynoecium :
Monocarpellary – The ovary with one carpel.
Bicarpellary – The ovary with Two carpels.
Tricarpellary – The ovary with Three carpels.
Tetracarpellary – The ovary with Four carpels.
Pentacarpellary – The ovary with Five carpels. .
Multicarpellary – The ovary with more than five carpels.
Syncarpous : All the carpels are fused.
Apocarpous : All the carpels are free.
Superior ovary : K, C, A develops from the base of the ovary.
Interior ovary : K, C, A develops from the upper part of the ovary.
Half superior ovary : K, C, A develops from the centre (Half) of the ovary.

Placentation :
Marginal (Ovules are arranged on Placenta present along the margins).
Axile (Ovules are arranged on the centre)
Basal (Ovules are arranged at the Base of the ovary).

Style : Terminal (develops above the ovary)
Laferal (develops from the latual side).

Stigma : Capitate (Round) Bifid (divided Hairy (with hairs).

AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Question 5.
Describe typical flowering plant in the taxonomic perspective.
Answer:
The plant is described beginning with vegetative characters like Habit (Herb or Shrub or Tree or Climber), Habitat (Hydrophyte, Mesophyte or Xerophyte), roots (Taproot or Fibrous root). Stem (aerial, erect, herbacious or woody), leaves (Simple or Compound, Reticulate or Parallel venation stipulate or exstipulate, Alternate or opposite or cyclic phyllotaxy) and then floral characters. Inflorescence (Recemose or Cymose) Flower and its floral parts followed fruit. After this, a floral diagram and floral flormula, are presented.

The floral formula is represented by some symbols of floral parts. In it, Br stands for Bracteate (Bracts are present). Ebr stands for Ebracteate (Bracts are absent) Brl stands for Bracteolate (Bracteoles are present). Ebrl stands for Ebrapteolates (Bracteoles are absent).
⊕ stands for Actinomorphic flower,
% stands for Zygomorphic flower.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 11
for inferior ovary. Floral formula also indicates the number of free or united members of the corresponding whorls. It also shows cohesion or Adhesion of stamens.

A floral diagram representing the number of parts of flower, the structure, arrangement, aestivation, cohesion and adhesion of stamens and position with respect to mother axis. The mother axis represents the posterior side of the flower and is indicated as dot at the top of the floral diagram. K, C, A, G are drawn in successive whorls. Calyx being the outermost and the gynoecium being the centre represented by T.S. of ovary. The bract represents the anterior side of the flower and is indicated at the bottom of the floral diagram.
AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms 3

Question 6.
Give an account of Bentham and Hooker’s classification of plants.
Answer:
Bentham and Hooker divided the flowering plants into three classes namely Dicotyledonae, Gymnospermae and Monocotyledonae. Dicotyledonae was divided into three subclasses namely polypetalae Gamopetalae and Monochlamydae. Polypetalae was divided into three series namely Thalamiflorae, disciflorae, Calyciflorae.

Thalamiflorae includes 6 order, disciflorae with 4 orders and Calyciflorae is with 5 orders. Gamopetalae was divided into three series namely Inferae (3 order) Heteromerae (3 orders) and Bicarpellatae (4 orders). Monocotyledonae was divided into seven series. Thus they grouped the flowering plants into 202 natural orders now called as families. Of these 165 families belongs Dicottyledonae, 3 to Gymnospermae and 34 belong to Monocotyledonae.

AP Inter 1st Year Botany Study Material Chapter 8 Taxonomy of Angiosperms

Question 7.
What is taxonomy 7 Give a brief account of different types of plant classification.
Answer:
Plant taxonomy deals with characterization, Identification nomenclature and classification of plants.

Several classifications were proposed by different taxonomists based on various criteria. All these classifications can be grouped into 3 types.

  1. Artificial systems,
  2. Natural systems,
  3. Phylogenetic systems.

1) Artificial systems :
These systems are based on one or few easily comparable characters like morphology, nutritional habits etc.
e.g.: A) Classification of plants into herbs, shrubs, trees etc., on the basis of form by Theophrastus in his book “Historia Plantarum”.

B) Sexual system of Linnaeus, in which he classify the plants on the basis of morphological nature of stamens and carpels.

2) Natural systems :
These are the systems in which plants are grouped on the basis of their natural reltionships taking into consideration all possible morphological characters. They believed that all species are specially created by God and they do not undergo any change.
E.g. : Classification of Bentham and Hooker.

3) Phylogenetic systems :
The classification of post-Darwinian period considered evolutionary trends in plants and so they are considered as Phylogenetic systems. In a phylogenetic system, primitive and advanced characters an recognised. While considering the status of a taxon, a comprehensive picture of all the characters is taken into account. The system proposed by Engler and Prantl in their book, “Die Naturlichen Planzenfamilien” (1887-1893) and by J.Hutchinson (1954) in his book, “Families of flowering plants” are examples. The latest phylogenetic system is APG (Angiospermic Phyogenetic Group) system.

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