Morphology of flowering plants Sample paper

Q1. A family delimited by the type of inflorescence is  

  • 1) Liliaceae
  • 2) Fabaceae
  • 3) Solanaceae
  • 4) Asteraceae

Solution

Asteraceae is characterised by a head or capitulum inflorescence consisting of a few or large number of flowers arranged on an axis surrounded by involucral bracts. 

Q2. Define epiphyllous stamens.

Solution

Epiphyllous stamens are the ones which are attached to the perianth.

Q3. Flowers in which only one set of essential organs is present are said to be

  • 1) Bisexual
  • 2) Dioecious
  • 3) Monoecious
  • 4) Unisexual
  • 5) Polygamous

Solution

In a unisexual, either an androecium or a gynoecium is present.

Q4. A simple cluster of radial leaves with exstipulate and parallel venation and cyme or umbel inflorescence are the characteristics of  

  • 1) Poaceae  
  • 2) Fabaceae  
  • 3) Liliaceae  
  • 4) Asteraceae  

Solution

Characters of family Liliaceae:

  • Leaves are mostly basal, alternate, linear, and exstipulate with parallel venation.
  • Inflorescence is solitary/cymose. Flowers are often in umbellate clusters.
  • Flowers are bisexual, actinomorphic and trimerous.
  • Perianth: There are six (3+3) tepals which are often united into a tube. Valvate aestivation is observed.
  • Androecium: Stamens are six, 3+3 in number.
  • Gynoecium is tricarpellary and syncarpous. Ovary is superior, trilocular with many ovules and with axile placentation.
  • Fruits are capsule-shaped and rarely berry.
  • Seed is endospermous.  

Q5. Differentiate between marginal and axial placentation.

Solution

Marginal Placentation Axial Placentation 1. The placenta is in the form of a ridge along the ventral suture of the ovary, and ovules develop on this ridge. 1. The placenta is axial, i.e. develops on the axis, and ovules are attached to the placenta in a multilocular form. 2. Example: Pea 2. Example: Tomato  

Q6. Plants with the given floral diagram         

  • 1) Are dicots  
  • 2) Have pinnately compound leaves  
  • 3) Are medicinal and perennial  
  • 4) Are leguminous  

Solution

The given floral diagram indicates family Liliaceae. Medicinal and perennial plants belong to this family.  

Q9. Describe epipetalous stamens.

Solution

When the stamens are attached to the petals, they are called epipetalous stamens.

Q8. Select the incorrect statement with respect to twiners. 

  • 1) Stems are very sensitive to contact.
  • 2) Tendrils and thorns are produced in twiners.
  • 3) None of the above.
  • 4) Flexible stem twins are produced due to nutritional growth.

Solution

Specialised climbing organs such as tendrils, thorns, spines and hooks are produced in climbers. 

Q9. Zygomorphic condition can be represented as

  • 1) P
  • 2) %

Solution

The ‘%’ sign is used to indicate the zygomorphic condition of flower.

Q10. State the type of root in sweet potato which stores food.

Solution

Adventitious roots in sweet potato are swollen to store food.

Q11. Tobacco and Petunia belong to family

  • 1) Fabaceae
  • 2) Poaceae
  • 3) Brassicaceae
  • 4) Solanaceae

Solution

Tobacco and Petunia belong to family Solanaceae.

Q12. A fruit developed from the hypanthodium inflorescence is 

  • 1) Caryopsis
  • 2) Syconus
  • 3) Hesperidium
  • 4) Sorosis

Solution

Syconus fruit develops from hypanthodium inflorescence. Example: Ficus carcia. In this type of inflorescence, the flask-shaped receptacle encloses female flowers which give rise to achene-like fruitlets.  

Q13. State the three parts of a typical leaf.

Solution

The three parts of a typical leaf are 1. Leaf base 2. Petiole 3. Lamina

Q14. Some roots resemble the shape of pillars. In which plants do we observe these roots? 

  • 1) Sugarcane
  • 2) Maize
  • 3) Banyan
  • 4) Pandanus

Solution

In Banyan, the roots grow vertically downward, penetrate the soil, become thick and assume the shape of pillars. 

Q15. The fruit of groundnut is 

  • 1) Nut
  • 2) Caryopsis
  • 3) Legume
  • 4) Berry

Solution

The legume or pod develops from a monocarpellary gynoecium. It is a dry dehiscent fruit which occurs in Leguminosae plants such as pea, gram, bean and groundnut. 

Q16. Hypanthodium is 

  • 1) Fruit
  • 2) Inflorescence
  • 3) Ovary
  • 4) Thalamus

Solution

Hypanthodium is a type of inflorescence in which the axis becomes fleshy and pear-shaped with a hollow cavity inside. Example: Ficus 

Q17. Find the odd one out. 

  • 1) Tribulus
  • 2) Evolvulus
  • 3) Bassela
  • 4) Tridax

Solution

Tridax is a decumbent trailer which branches after growing horizontally for some length and then grows vertically upwards. 

Q18. Find the odd one out.  

  • 1) None of the above
  • 2) Turnip
  • 3) Beet
  • 4) Radish

Solution

Radish is an example of a fusiform root, whereas the rest are examples of a napiform root. 

Q19. Pneumatophores are present in

  • 1) Xerophytes
  • 2) Halophytes
  • 3) Mesophytes
  • 4) Hygrophytes

Solution

Halophytes are the plants found in areas of high salinity such as estuaries and marshy regions. These plants are usually rooted in water logged, anaerobic mud. Many roots come out of ground and grow vertically upwards to get oxygen for respiration. These roots are called pneumatophores.

Q20. Define root cap.

Solution

The root cap is a thimble-like structure which covers the apex of the root.

Q21. Select the incorrect statement regarding a fusiform root. 

  • 1) It is spindle shaped.
  • 2) Secondary roots arise from the thin apical part of the tap root.
  • 3) The middle portion of the root is thick which gradually tapers towards the apex.
  • 4) Thin secondary roots arise from the apical portion.

Solution

Secondary roots arise from the thin apical part of the tap root. This is a characteristic of a napiform root. 

Q22. State the significance of the floral formula.

Solution

Significance of floral formula: 1. The floral formula provides information about the number of petals of a flower, their arrangement and the relation they have with one another. 2. It also shows the cohesion and adhesion within parts of whorls and between whorls.

Q23. The thorn of Bougainvillea and the tendril of Cucurbita are examples of

  • 1) Vestigial organs
  • 2) Analogous organs
  • 3) Retrogressive evolution
  • 4) Homologous organs

Solution

Homologous organs are the organs which exhibit anatomical similarities but perform different function. The thorn of Bougainvillea and the tendril of Cucurbita are modifications of stem. Both arise from the axillary bud. Thorns provide protection to plants, while tendrils provide support to the climbing plant.

Q24. In monocotyledonous seeds, the endosperm is separated from the embryo by a distinct layer known as  

  • 1) Aleurone layer  
  • 2) Coleoptile  
  • 3) Scutellum  
  • 4) Tegmen  
  • 5) Testa  

Solution

The aleurone layer is the outer covering of the endosperm. It is proteinous in nature.  

Q25. Define placentation.

Solution

The arrangement of ovules within the ovary is known as placentation.

Q26. The plant which bears clinging roots is 

  • 1) Trapa
  • 2) Screw pine
  • 3) Podostemon
  • 4) Orchid

Solution

Clinging roots are modified adventitious roots meant for providing mechanical support. Examples: Orchids, ivy 

Q27. Define venation.

Solution

The arrangement of veins and veinlets in the lamina of the leaf is called venation.

Q28. Explain the following terms:     (a) Perigynous flower     (b) Hypogynous flower     (c) Epigynous flower  

Solution

(a) Perigynous flower: The gynoecium is located in the centre, and other parts of the flower are located on the rim of the thalamus almost at the same level.     Examples: Rose, peach     (b) Hypogynous flower: The gynoecium is located at the highest point, i.e. the ovary is superior and the other parts are situated below it.     Examples: China rose, brinjal     (c) Epigynous flower: The margin of the thalamus grows over and encloses the ovary completely. The margins of the flower get fused with the other parts of the flower which rise above the ovary.  

Q29. Differentiate between fibrous roots and adventitious roots.

Solution

Fibrous Roots Adventitious Roots 1. Roots arise from the base of the stem. 1. Roots arise from the parts of the plant other than the radical. 2. It is found in wheat. 2. It is found in grass and banyan tree.  

Q30. Describe the gynoecium of a typical flower.

Solution

The gynoecium is the female reproductive part of a typical flower. It is made of one or more carpels. A carpel consists of the following three parts: 1. Ovary: It is the enlarged basal part of the flower. Each ovary bears one or more ovules attached to the placenta. 2. Style: The style is a tube-like structure which connects the ovary to the stigma. 3. Stigma: It is the receptive surface for pollen grains. If the carpels are free from one another, then they are called apocarpous. If they are fused, then they are called syncarpous.NA

Q31. A horizontal underground stem is a

  • 1) Phylloclade
  • 2) Rhizome
  • 3) Corm
  • 4) Rhizoid

Solution

Rhizomes are also called root stalks. They are the underground growth of plants from which the parts which grow above the ground develop. A rhizome usually grows perpendicular to the direction of the force of gravity, i.e. they grow horizontal.

Q32. State the function of root hair.

Solution

Root hair absorbs water and minerals from the soil.

Q33. A flower which can be divided into equal vertical halves by more than one plane of division is

  • 1) Zygomorphic
  • 2) Heteromorphic
  • 3) Actinomorphic
  • 4) Cyclic

Solution

Floral symmetry is the shape, size and arrangement of floral appendages around the axis of a flower. On the basis of floral symmetry, three conditions are seen in flowers: 1. Actinomorphic: Flowers are with radial symmetry. A flower can be divided into two equal radial halves in any radial plane passing through its centre. Example: Datura 2. Zygomorphic: These flowers can be divided into halves only in one plane. Example: Pea 3. Asymmetric: Flowers are cannot be divided into equal halves in any vertical plane. Example: Canna

Q34. The roots which penetrate the host tissues are called 

  • 1) Epiphytic roots
  • 2) Floating roots
  • 3) Haustorial roots
  • 4) Assimilatory roots

Solution

The roots of parasitic plants which penetrate the host tissues to absorb nourishment are called haustorial roots.  

Q35. The fruit of Mangifera indica is 

  • 1) Capsule
  • 2) Berry
  • 3) Siliqua
  • 4) Drupe

Solution

Drupe in mango is the fruit which is one-seeded, simple, fleshy and develops from a multicarpellary gynoecium.  

Q36. The fibrous root system is mostly found in

  • 1) Bryophytes
  • 2) Pteridophytes
  • 3) Monocot plants
  • 4) Dicot plants

Solution

In monocots, the primary root is short lived. It is replaced by a large number of roots which originate from the base of the stem. These roots constitute the fibrous root system.

Q37. Name the roots which arise from any other plant part. 

  • 1) Fusiform root
  • 2) Adventitious root
  • 3) Tap root
  • 4) Fibrous root

Solution

The roots which arise from any other plant part except radicle are called adventitious roots. 

Q38. Ginger is an underground stem. It is distinguished from the root because

  • 1) It has xylem and vessels.
  • 2) It stores food.
  • 3) It lacks chlorophyll.
  • 4) It has nodes and internodes.

Solution

A root does not have nodes and internodes, while a stem is characterised by nodes and internodes. A node is a region on the stem from which leaves develop, while an internode is the region between two nodes. Because ginger shows the presence of node and internode, it is a modified underground stem.

Q39. A fibrous root system is excellent for Food storage Nitrogen fixation Absorbing water from deeper layers of soil Providing good anchorage for the plant

  • 1) (i) and (iv) are correct.
  • 2) (iv) and (ii) are correct.
  • 3) (i), (ii), (iii) and (iv) are correct.
  • 4) (i), (iii) and (iv) are correct.

Solution

The main functions of fibrous roots are (i) Absorption of water and minerals from the soil (ii) Providing a proper anchorage to plant parts (iii) Storing reserve food material (iv) Synthesis of plant growth regulators

Q40. Pulvinus is seen in 

  • 1) Mimosa pudica
  • 2) Acacia nilotica
  • 3) Podostemon
  • 4) Utricularia

Solution

The swollen leaf base is called pulvinus. It helps to perform seismonastic movements in Mimosa pudica. 

Q41. Trimerous flower, superior ovary and axile placentation are the characteristics of

  • 1) Solanaceae
  • 2) Compositae
  • 3) Cucurbitaceae
  • 4) Liliaceae

Solution

Characters of family Liliaceae: 1. Leaves are mostly basal, alternate, linear, and exstipulate with parallel venation. 2. Inflorescence is solitary/cymose. Flowers are often in umbellate clusters. 3. Flowers are bisexual, actinomorphic and trimerous. 4. Perianth: There are six (3+3) tepals which are often united into a tube. Valvate aestivation is observed. 5. Androecium: Stamens are six, 3+3 in number. 6. Gynoecium is tricarpellary and syncarpous. Ovary is superior, trilocular with many ovules and with axile placentation. 7. Fruits are capsule-shaped and rarely berry. 8. Seed is endospermous.

Q42. Write the vegetative characters of the family Fabaceae.

Solution

The vegetative characters of the family Fabaceae are as follows: 1. The stem is erect or a climber. 2. Leaves are alternate, pinnately compound or simple. The leaf base is pulvinate, stipulate and leaf venation is reticulate.

Q43. Vivipary is characteristic of 

  • 1) Mesophytes
  • 2) Halophytes
  • 3) Hygrophytes
  • 4) Xerophytes

Solution

Vivipary is a special type of seed germination which occurs in halophytes in which seeds germinate inside the fruit when it is still attached to the parent plant. 

Q44. Describe the different regions of the root.

Solution

The different regions of the root are as follows: 1. Root cap: It covers the apex of roots which grow through the soil. 2. Region of Meristematic Activity: This region is a few millimetres above the root cap. The cells are thin-walled and small with dense protoplasm. The cells divide repeatedly. 3. Region of Elongation: This region is proximal to the region of meristematic activity. The cells in this region undergo rapid elongation and enlargement. This zone is responsible for the growth in length of the root. These cells gradually differentiate and mature. 4. Zone of Maturation: The zone of maturation is proximal to the zone of elongation. Its epidermal cells give rise to root hair cells which absorb water from the soil.

Q45. Colchicine is obtained from which of the following families?  

  • 1) Malvaceae  
  • 2) Brassicaceae  
  • 3) Liliaceae  
  • 4) Poaceae  

Solution

Colchicine is extracted from the plant Colchicum autumnale which belongs to family Liliaceae.  

Q46. The edible part in litchi is 

  • 1) Pericarp
  • 2) Mesocarp
  • 3) Fleshy aril
  • 4) Endosperm

Solution

Aril is a fleshy covering on the seed, arising as an upgrowth of the funicle or base of the ovule. It is the aril of litchi which we eat. 

Q47. Vexillary aestivation is characteristic of family  

  • 1) Fabaceae  
  • 2) Solanaceae  
  • 3) Asteraceae  
  • 4) Brassicaceae  

Solution

Vexillary aestivation is characteristic of family Fabaceae. In this type of aestivation, the largest (standard) overlaps the two lateral petals (wings) which overlap the two smallest anterior petals (keel).  

Q48. Define leaf.

Solution

A lateral, generally flattened structure which is borne on the stem is called a leaf.

Q49. What type of placentation is seen in sweet pea?

  • 1) Axile
  • 2) Marginal
  • 3) Basal
  • 4) Free central

Solution

In marginal placentation, the placenta forms a ridge on the ventral suture of the ovary and the ovules are borne on this ridge.   Such placentation is seen in pea.

Q50. Roots of which plant contain an oxidising agent? 

  • 1) Mustard
  • 2) Radish
  • 3) Soyabean
  • 4) Carrot

Solution

The roots of soyabean contain leghaemoglobin. Their main function is to help in the transport of oxygen to the respiring symbiotic bacterial cells in a manner analogous to haemoglobin which transports oxygen to respiring tissues in animals. 

Q51. Describe the structure of a dicotyledonous seed.

Solution

A dicotyledonous seed is covered by a seed coat. A seed coat is made of two layers—an outer testa and an inner tegmen. There is a scar on the seed coat called hilum. Through the hilum, the developing seeds are attached to the fruit. A micropyle is the small pore present just above the hilum. An embryo is enclosed by the seed coat. The embryo has an embryonal axis and two cotyledons. The cotyledons are fleshy, and they serve as the food reserves for the developing embryo. At the two ends of the embryonal axis are the radicle and the plumule.

Q52. State the function of the petiole.  

Solution

The petiole holds the lamina. It helps the leaf to flutter in the wind, thus cooling the leaf.  

Q53. Name the plants whose stems are modified to store food.

Solution

Plants whose stems are modified to store food are potato, ginger, turmeric, Colocasia and Zaminkand.

Q54. Rhizomes which grow vertically upwards are

  • 1) Bulbils
  • 2) Corms
  • 3) Stolon
  • 4) Root stock

Solution

A root stock is a part of a plant which is underground. From the root stock, the aboveground growth can develop. The rhizome is one such growth which rises from the root stock.

Q55. What is the root cap? State its function.

Solution

The root cap is the structure which is thimble-like and covers the root apex. It protects the tender apex of the root while it makes its way through the soil.

Q56. New banana plants develop from 

  • 1) Rhizome
  • 2) Seed
  • 3) Sucker
  • 4) Stolon

Solution

A sucker is the modification of a stem which originates from the basal and underground portion of the main stem. Examples: Banana, Chrysanthemum 

Q57. Write the scientific name for the plant which belongs to the family Liliaceae and from which colchicine is extracted.

Solution

 Colchicum autumnale 

Q58. Describe the floral characters of the family Solanaceae.

Solution

The floral characters of the family Solanaceae are as follows:

  • 1. Inflorescence is solitary, axial or cymose.
  • 2. Flowers are bisexual, actinomorphic.
  • 3. Calyx: Five sepals, gamosepalous. It shows valvate aestivation.
  • 4. Corolla: Five petals, gamopetalous. It shows valvate aestivation.
  • 5. Androecium: Five stamens, epipetalous.
  • 6. Gynoecium: Superior, bicarpellary, syncarpous ovary. Ovary is bilocular with many ovules.NA

Q59. What is modification of roots? Write the modification of roots found in the following plants:     (a) Maize     (b) Carrot     (c) Banyan tree     (d) Rhizophora  

Solution

The roots in some plants are modified for support, storage of food and respiration.     (a) Maize: Stilt roots arise from the nodes of the stem to support the plant.     (b) Carrot: Roots are swollen and store food.     (c) Banyan Tree: Prop roots arise to support the tree.     (d) Rhizophora: Roots arise above the ground to obtain oxygen for respiration.  

Q60. Which of the following represents the floral characters of Liliaceae?  

  • 1) Trimerous, actinomorphic, polyandrous, superior ovary, axile placentation  
  • 2) Six petals, zygomorphic, six stamens, bilocular ovary, axile placentation  
  • 3) Unisexual, actinomorphic, trilocular, inferior ovary, axile placentation  
  • 4) Tetramerous, actinomorphic, polyphyllous, unilocular ovary, axile placentation  
  • 5) Bisexual, zygomorphic, gamophyllous, inferior ovary, marginal placentation  

Solution

Trimerous, actinomorphic, polyandrous, superior ovary and axile placentation are characters which represent the family Liliaceae.  

Q61. Pulses such as gram, moong and soyabean belong to family  

  • 1) Solanaceae  
  • 2) Liliaceae  
  • 3) Poaceae  
  • 4) Fabaceae  

Solution

Gram, moong and soyabean belong to family Fabaceae.  

Q62. Which of the following is the correct arrangement of corolla in family Papilionoideae?  

  • 1) C1 + (2) – (2)  
  • 2) C1 + (2) – 2  
  • 3) C(5) A(5)  
  • 4) C1 + 2 + (2)  

Solution

In family Papilionoideae, the corolla has 5 petals and is polypetalous. Two anterior petals form a keel which encloses the stamens and pistil. Hence, C1 + 2 + (2) is the correct option.  

Q63. Name the three regions of the root.

Solution

The three regions of the root are 1. Region of meristematic activity 2. Region of elongation 3. Region of maturation

Q64. Name the meristem from which leaves originate.

Solution

Leaves originate from the shoot apical meristem.

Q65. Name the proteinaceous layer present in a monocotyledonous seed.

Solution

The aleurone layer is a proteinaceous layer present in a monocotyledonous seed.

Q66. What is phyllotaxy? State the three types of phyllotaxy.

Solution

Phyllotaxy is the arrangement of leaves on the stem or branch. The three types of phyllotaxy are as follows: 1. Alternate 2. Opposite 3. Whorled

Q67. Name the region of the root whose epidermal cells form root hair.

Solution

The epidermal cells of the region of maturation form root hair.

Q68. Define fruit. Give two examples of a drupe.

Solution

A fruit is a mature ripened ovary developed after fertilisation. Mango and coconut are examples of a drupe.

Q69. Name the accessory organs of a typical flower.

Solution

Calyx and corolla are the accessory organs of a flower.

Q70. Define thalamus.

Solution

The thalamus is the swollen end of the pedicel on which the four whorls, i.e. calyx, corolla, androecium and gynoecium, are arranged.

Q71. Explain the different kinds of modifications of stem.

Solution

Modification of stem:

  • 1. Underground stem: Stores food. It also acts as organs of perennation to face conditions unfavourable for growth. Examples: Potato, turmeric
  • 2. Stem tendrils: They develop from axillary buds. They are slender, spirally coiled and help plants to grow. Example: Pumpkins 3. Thorns: Axillary buds get modified into thorns. They are woody, straight and pointed. They protect plants from animals. Example: Citrus
  • 4. Photosynthetic stem: In arid regions, stems become flat and fleshy. They contain chlorophyll to carry out photosynthesis. Example: Euphorbia
  • 5. Reproductive stems: In some plants such as Jasmine, a slender lateral branch arises from the base of the main axis. After growing aerially for some time, it arches down to touch the ground. In plants such as Chrysanthemum, the lateral branches originate from the basal and underground portion of the main stem. It grows horizontally beneath the soil and comes out obliquely upwards to give rise to leafy shoots.

Q72. Name the family which was earlier known as Papilionoideae.

Solution

The family Fabaceae was earlier known as Papilionoideae.

Q73. Explain the parietal type of placentation with the help of a diagram.  

Solution

In parietal placentation, the ovules develop on the inner wall of the ovary. The ovary is one-chambered, but it becomes two-chambered due to the formation of the false septum.     The parietal type of placentation is seen in mustard flower.    

Q74. Describe the arrangement of calyx and corolla of sun hemp.  

Solution

Calyx of sun hemp:  There are five sepals. It is gamosepalous and shows imbricate aestivation.

Corolla of sun hemp: There are five petals. It is polypetalous consisting of posterior standard, two lateral wings and two anterior petals forming a keel. It exhibits vexillary aestivation.  

Q75. Cite examples of non-endospermous seeds.

Solution

Examples of non-endospermous seeds are as follows: Bean, gram, pea

Q76. Define adventitious roots.

Solution

Roots which develop or arise from the other parts of the plant but not from the radical are called adventitious roots.

Q77. Explain the three types of phyllotaxy and give examples of each type.  

Solution

The three types of phyllotaxy are as follows:     1. Alternate type of phyllotaxy:     A single leaf arises at each node in an alternate manner.     Examples: China rose, Sun flower     2. Opposite type of phyllotaxy:     A pair of leaves arise at each node and lie opposite to each other.     Examples: Calotropis, Guava     3. Whorled type of phyllotaxy:     More than two leaves arise at a node and form a whorl.     Example: Alstonia  

Q78. The edible part of mango is

  • 1) Epicarp
  • 2) Receptacle
  • 3) Mesocarp
  • 4) Endocarp

Solution

The mesocarp in mango is the middle fleshy edible part.

Q79. State the name of the family of plants where flowers show valvate aestivation and tepals are often united in a tube.

Solution

Liliaceae

Q80. Write the symbols for the following used in floral formula:     (a) Zygomorphic nature of flower     (b) Inferior ovary  

Solution

(a) Zygomorphic nature of flower – %     (b) Inferior ovary – top enclose G  

Q81. Differentiate between pinnately compound leaves and palmately compound leaves.

Solution

Pinnately Compound Leaves Palmately Compound Leaves 1. Leaflets are present on a common axis, i.e. on a rachis. 1. Leaflets are attached to the tip of the petiole. 2. Example: Neem 2. Example: Silk cotton  

Q82. Describe the gynoecium of ground nut.  

Solution

In ground nut, the ovary is superior, monocarpellary and unilocular with many ovules. The gynoecium has a single style.  

Q83. Name the plants of the family Solanaceae which yield each of the following. (a) Food (b) Fumigatory (c) Spice (d) Medicine

Solution

(a) Food – Tomato (b) Fumigatory – Tobacco (c) Spice – Chilli (d) Medicine – Belladonna

Q84. Define inflorescence. On what basis are the two types of inflorescences identified? Explain the two types of inflorescences.

Solution

The arrangement of flowers on the floral axis is called an inflorescence. Based on whether the apex gets converted into a flower or it continues to grow, the two types of inflorescences are identified as racemose and cymose. The two types of inflorescences are as follows: . Racemose inflorescence: The main axis grows and the flowers grow laterally in acropetal succession. Cymose inflorescence: The main axis terminates in a flower. Flowers are borne in basipetal order. The main axis has limited growth.

Q85. Define apocarpous gynoecium.

Solution

When more than one carpel is present, they may be free. Such a gynoecium is known as an apocarpous gynoecium.

Q86. Which plant will lose its economic value if its fruits are produced by induced parthenocarpy? 

  • 1) Pomegranate
  • 2) Orange
  • 3) Banana
  • 4) Grape

Solution

The edible part of pomegranate is the testa. It is not formed if fruits are produced by parthenocarpy. However, in fruits such as grapes, induced parthenocarpy is beneficial as they contain seeds. 

Q87. Define the following and give one example of each: (a) Bisexual flower (b) Unisexual flower

Solution

(a) Bisexual flower: It is a flower in which both androecium and gynoecium are present. Example: Tulip (b) Unisexual flower: It is a flower with only androecium or gynoecium. Example: Flower of papaya plant

Q88. Distinguish between the families Solanaceae and Liliaceae on the basis of gynoecium.  

Solution

Differences between Solanaceae and Liliaceae on the basis of their gynoecia.     Solanaceae     Liliaceae     1. Gynoecium is bicarpellary.      1. Gynoecium is tricarpellary.     2. Ovary is bilocular.     2. Ovary is trilocular.     3. It shows the presence of swollen placenta.     3. It shows axile placentation.        

Q89. Name the region of the root which is responsible for the growth in length of the root.

Solution

The region of elongation is responsible for the growth in length of the root.

Q90. Describe the floral formula.

Solution

A floral formula is a representation of different parts of a flower and its arrangement by using certain symbols. Symbols Part indicated by the symbol Br Bracteate K Calyx C Corolla A Androecium G Superior Ovary (Gynoecium)   Inferior Ovary (Gynoecium) – Male Flower – Female Flower – Bisexual Flower –  Actinomorphic Flower % Zygomorphic Flower Fusion is indicated by enclosing the figure in brackets. Adhesion is indicated by drawing a line above the symbols of the floral parts.

Q91. Define aestivation. Explain different types of aestivation.

Solution

Aestivation is the mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl. There are four main types of aestivation. They are as follows:

  • Valvate aestivation: Sepals or petals in a whorl just touch one another. They do not overlap one another.   It is observed in Calotropis.
  • Twisted aestivation: One margin of the appendage overlaps the margin of the next appendage.     Such type of aestivation is seen in lady’s finger, china rose and cotton.
  • Imbricate aestivation: Margins of sepals or petals overlap one another but not in any particular direction.   It is seen in Gulmohar and Cassia.
  • Vexillary aestivation: It is also known as Papilionaceous type of aestivation.   There are five petals. The largest petal (called standard) overlaps the two lateral petals (called wings) which further overlap the two smallest anterior petals (called keel).

Q92. What is aestivation? Distinguish between valvate aestivation and twisted aestivation.

Solution

Aestivation is the mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl. Valvate Aestivation Twisted Aestivation 1. Sepal or petals in a whorl just touch one another. They do not overlap. 1. One margin of the floral appendage overlaps the margin of the next appendage. 2. Example: Calotropis 2. Example: China rose  

Q93. Name the reproductive organs of a typical flower.

Solution

Androecium and gynoecium are the reproductive organs of a typical flower.

Q94. What does a dot represent in a floral diagram?

Solution

A dot in the floral diagram represents the position of the flower axis with respect to the flower.

Q95. Bicarpellary, syncarpous ovary with axile placentation is seen in the plants of family

  • 1) Caesalpiniaceae
  • 2) Asteraceae
  • 3) Malvaceae
  • 4) Solanaceae

Solution

The gynoecium in the Solanaceae family is bicarpellary, syncarpous, with an ovary which is superior and bilocular, and the placenta is swollen with many ovules. The placentation is of axile type.

Q96. How is fusion indicated in a floral formula?

Solution

Fusion in a floral formula is indicated by enclosing the figure in brackets.

Q97. What are bracteate and ebracteate flowers?

Solution

Flowers with bracts (i.e. reduced leaf found at the base of the pedicel) are called bracteate flowers, and ebracteate flowers are the flowers without bracts.

Q98. What is a compound leaf? Give one example.

Solution

When the incisions of the lamina reach the midrib and break the main leaf into many leaflets, such a leaf is called a compound leaf. Example: Neem

Q99. How is adhesion indicated in a floral formula?

Solution

In a floral formula, adhesion is indicated by drawing a line above the symbols of the floral parts.

Q100. Distinguish between reticulate venation and parallel venation.

Solution

Reticulate Venation Parallel Venation 1. The veinlets form a network. 1. The veins run parallel to each other within a lamina. 2. It is seen in dicotyledonous plants. 2. It is seen in monocotyledonous plants.

Q101. Describe the structure of a monocotyledonous seed.  

Solution

The seed coat which covers the seed is membranous and fused with the cell wall. The endosperm is bulky, and it serves as the food reserve.     The outer covering of the endosperm is a proteinous layer called the aleurone layer.     A small embryo is located in a groove at one end of the endosperm.     A large shield-shaped cotyledon called the scutellum is present.     The embryo has a short axis with the radicle and plumule.     The radicle and plumule are enclosed in sheaths called coleorhiza and coleoptile, respectively.

Q102. What are thorns? Give one example of a plant in which thorns are found.

Solution

Thorns are the modified axillary buds of the stem. Thorns are found in citrus plants.

Q103. Name two plants whose tap roots are modified to store food.

Solution

Carrot Turnip

Q104. Distinguish between zygomorphic flower and actinomorphic flower.

Solution

Zygomorphic Flower Actinomorphic Flower 1. The flower can be divided into two similar halves in one particular plane. 1. The flower can be divided into two equal radial halves in any radial plane passing through the central axis of the flower. 2. Examples: Mustard, Datura 2. Examples: Gulmohar, Pea