Q51. When stamens are united in one bundle, the condition is called:
a) Polyadelphous
b) Diadelphous
c) Monadelphous
d) Syngenesious
Show Answer
Correct Answer: c) Monadelphous
Explanation: Monadelphous condition is when the filaments of stamens are fused together into one bundle, while anthers are free, e.g., in china rose. Diadelphous has stamens united in two bundles (pea), polyadelphous in more than two bundles (citrus), and syngenesious has anthers fused and filaments free (sunflower).
Q52. When carpels are fused together, the gynoecium is said to be:
a) Apocarpous
b) Syncarpous
c) Monocarpellary
d) Multicarpellary
Show Answer
Correct Answer: b) Syncarpous
Explanation: Syncarpous gynoecium is when carpels are fused together, e.g., in mustard and tomato. Apocarpous gynoecium is when carpels are free, e.g., lotus and rose. Monocarpellary gynoecium has one carpel, and multicarpellary has many carpels – these terms relate to the number of carpels, not their fusion.
Q53. When carpels are free, the gynoecium is said to be:
a) Syncarpous
b) Apocarpous
c) Polycarpellary
d) Multilocular
Show Answer
Correct Answer: b) Apocarpous
Explanation: Apocarpous gynoecium is when carpels are free, not fused together, e.g., in lotus and rose. Syncarpous is when carpels are fused. Polycarpellary refers to having many carpels, and multilocular refers to having multiple chambers in the ovary.
Q54. Placentation refers to:
a) Arrangement of placentae in ovary
b) Arrangement of ovules within the ovary
c) Arrangement of flowers on placenta
d) Arrangement of fruits on placenta
Show Answer
Correct Answer: b) Arrangement of ovules within the ovary
Explanation: Placentation refers to the arrangement of ovules within the ovary. Different types include marginal, axile, parietal, free central, and basal. Placenta is a tissue in the ovary to which ovules are attached.
Q55. In marginal placentation, the placenta forms a ridge along the:
a) Ventral suture of the ovary
b) Dorsal suture of the ovary
c) Base of the ovary
d) Apex of the ovary
Show Answer
Correct Answer: a) Ventral suture of the ovary
Explanation: In marginal placentation, the placenta forms a ridge along the ventral suture of the ovary, and ovules are borne on this ridge in two rows, characteristic of pea and bean family (legumes). Axile placentation has ovules on central axis, parietal on ovary wall, free central in center without septa, and basal at ovary base. Dorsal suture is not typically involved in placentation description.
Q56. In axile placentation, ovules are attached to:
a) Ovary wall
b) Central axis in a multilocular ovary
c) Base of the ovary
d) Free central column
Show Answer
Correct Answer: b) Central axis in a multilocular ovary
Explanation: In axile placentation, the placenta is axial, and ovules are attached to it in a multilocular ovary (ovary with multiple chambers), as seen in china rose, tomato, and lemon. Parietal is on ovary wall, basal is at base, and free central has central column without septa.
Q57. In parietal placentation, ovules develop on the:
a) Central axis
b) Ovary wall or peripheral part
c) Base of ovary
d) Septa in ovary
Show Answer
Correct Answer: b) Ovary wall or peripheral part
Explanation: In parietal placentation, the ovules develop on the inner wall of the ovary or on peripheral part. The ovary is typically unilocular, but may become bilocular due to false septum formation (repleum), e.g., mustard and Argemone. Axile is on central axis, basal is at base, and septa are involved in axile placentation dividing ovary into chambers.
Q58. In free central placentation, ovules are borne on:
a) Central axis without septa
b) Ovary wall
c) Base of ovary
d) Septa of ovary
Show Answer
Correct Answer: a) Central axis without septa
Explanation: In free central placentation, ovules are borne on a central column or axis in a unilocular ovary. Septa are absent in free central placentation, distinguishing it from axile placentation, e.g., Dianthus and Primrose. Parietal is on ovary wall, and basal is at ovary base.
Q59. In basal placentation, the placenta develops at the:
a) Base of the ovary
b) Apex of the ovary
c) Periphery of the ovary
d) Center of the ovary
Show Answer
Correct Answer: a) Base of the ovary
Explanation: In basal placentation, the placenta develops at the base of the ovary, and a single ovule is attached to it at the base, as seen in sunflower and marigold. Apex of ovary is apical placentation (not a major type), periphery is parietal, and center could be axile or free central depending on septa presence.
Q60. Fruit develops from the:
a) Thalamus
b) Ovule
c) Ovary
d) Seed
Show Answer
Correct Answer: c) Ovary
Explanation: Fruit is the mature or ripened ovary, developed after fertilization. The ovary wall forms the pericarp of the fruit. Thalamus forms false fruits in some cases, ovule develops into seed, and seed gives rise to new plant.
Q61. Parthenocarpic fruits develop:
a) After fertilization
b) Without fertilization
c) From thalamus
d) From receptacle
Show Answer
Correct Answer: b) Without fertilization
Explanation: Parthenocarpic fruits are fruits that develop without fertilization of the ovary. Such fruits are seedless, e.g., banana, grape. Fertilization is usually required for fruit development (true fruits), thalamus and receptacle form false fruits, and seed develops from ovule after fertilization.
Q62. Which of the following is a false fruit?
a) Mango
b) Guava
c) Apple
d) Tomato
Show Answer
Correct Answer: c) Apple
Explanation: Apple is a false fruit (pseudocarp) because in its development, along with the ovary, other floral parts like thalamus also contribute to the fruit formation, making it not just from the ovary. Mango, guava, and tomato are true fruits (developed only from ovary).
Q63. The edible part of apple is:
a) Pericarp
b) Thalamus
c) Mesocarp
d) Endocarp
Show Answer
Correct Answer: b) Thalamus
Explanation: The edible fleshy part of apple is the thalamus, which becomes fleshy and edible, while the ovary forms the core and seed containing part. In true fruits, pericarp is the edible part. Mesocarp is the edible part in mango, endocarp in almond, but thalamus in apple.
Q64. The seed coat is derived from:
a) Ovary wall
b) Ovule integuments
c) Nucellus
d) Endosperm
Show Answer
Correct Answer: b) Ovule integuments
Explanation: Seed coat develops from the integuments (outer layers) of the ovule. Usually, the outer integument forms testa and inner integument forms tegmen, together forming the seed coat, which provides protection to the seed. Ovary wall becomes pericarp, nucellus is tissue within ovule, and endosperm is nutritive tissue within seed.
Q65. The embryo in seed develops from:
a) Endosperm
b) Zygote
c) Ovule
d) Antipodal cells
Show Answer
Correct Answer: b) Zygote
Explanation: The embryo in a seed develops from the zygote, which is formed by the fusion of male and female gametes during fertilization. Zygote undergoes cell division and differentiation to form the embryo, the young plant within the seed. Endosperm is nutritive tissue, ovule becomes seed, and antipodal cells are part of embryo sac and degenerate after fertilization.
Q66. Albuminous seeds are those in which:
a) Endosperm is completely consumed
b) Endosperm persists in the mature seed
c) Embryo is absent
d) Seed coat is absent
Show Answer
Correct Answer: b) Endosperm persists in the mature seed
Explanation: Albuminous (or endospermic) seeds are those in which endosperm, the nutritive tissue, persists in the mature seed because it is not completely consumed by the developing embryo, e.g., wheat, maize, castor, sunflower. Non-albuminous (or exalbuminous) seeds lack endosperm in mature seed. Embryo and seed coat are always present in seeds (unless abortive).
Q67. Non-albuminous seeds are those in which:
a) Endosperm persists
b) Endosperm is completely consumed by developing embryo
c) Embryo is very large
d) Seed is very small
Show Answer
Correct Answer: b) Endosperm is completely consumed by developing embryo
Explanation: Non-albuminous (or exalbuminous) seeds are those in which the endosperm is completely consumed by the developing embryo before seed maturation, so endosperm is absent or negligible in mature seed, e.g., pea, bean, groundnut. Albuminous seeds retain endosperm. Embryo size and seed size are not defining factors for albuminous/non-albuminous.
Q68. Perisperm is a persistent:
a) Endosperm
b) Nucellus
c) Integument
d) Embryo sac
Show Answer
Correct Answer: b) Nucellus
Explanation: Perisperm is a persistent remnant of the nucellus, which is the nutritive tissue surrounding the embryo sac in the ovule. In some seeds, like black pepper and beet, nucellus is not fully consumed during embryo development and persists as perisperm, alongside endosperm. Endosperm is usually triploid, nucellus is diploid, and integument forms seed coat.
Q69. Coleorhiza and coleoptile are protective sheaths covering:
a) Radicle and plumule respectively in monocot seed
b) Plumule and radicle respectively in monocot seed
c) Cotyledons in dicot seed
d) Endosperm in monocot seed
Show Answer
Correct Answer: a) Radicle and plumule respectively in monocot seed
Explanation: In monocot seeds like grasses, coleorhiza is a protective sheath covering the radicle and root cap, and coleoptile is a protective sheath covering the plumule and first few leaves. They protect these delicate structures during germination as they emerge from the seed. Cotyledons are embryonic leaves, and endosperm is nutritive tissue, not covered by these sheaths specifically in this context.
Q70. Scutellum in a grass embryo is:
a) Coleoptile
b) Coleorhiza
c) Cotyledon
d) Endosperm
Show Answer
Correct Answer: c) Cotyledon
Explanation: Scutellum is the single cotyledon in grass (monocot) embryos. It is shield-shaped and serves to absorb nutrients from the endosperm during seed germination and seedling establishment. Coleoptile covers plumule, coleorhiza covers radicle, and endosperm is the nutritive tissue itself, scutellum is the cotyledon.
Q71. The aleurone layer in cereal grains is rich in:
a) Starch
b) Proteins
c) Lipids
d) Cellulose
Show Answer
Correct Answer: b) Proteins
Explanation: Aleurone layer is the outermost proteinaceous layer of the endosperm in cereal grains (like maize, wheat, barley). It is rich in proteins and enzymes, and plays a role in digestion and mobilization of endosperm reserves during seed germination. Starch is in the main endosperm, lipids in oilseeds, and cellulose is in cell walls, but aleurone layer is specifically protein-rich.
Q72. Aleurone layer is part of:
a) Seed coat
b) Endosperm
c) Embryo
d) Pericarp
Show Answer
Correct Answer: b) Endosperm
Explanation: Aleurone layer is part of the endosperm in cereal grains. It is the outermost layer of the endosperm, surrounding the starchy endosperm. Seed coat is derived from integuments, embryo from zygote, and pericarp from ovary wall, aleurone is specifically endosperm-related.
Q73. Which of the following tissue systems provides mechanical support, protection, and storage in plants?
a) Epidermal tissue system
b) Vascular tissue system
c) Ground tissue system
d) Conducting tissue system
Show Answer
Correct Answer: c) Ground tissue system
Explanation: Ground tissue system includes all tissues except epidermis and vascular tissues. It comprises parenchyma, collenchyma, and sclerenchyma, and performs diverse functions like storage, photosynthesis, support, and packing of other tissues. Epidermal is for protection, vascular for conduction, ground tissue is more versatile in functions.
Q74. Which of the following is NOT a function of epidermal tissue system?
a) Protection from mechanical injury
b) Prevention of water loss
c) Gaseous exchange through stomata
d) Conduction of water and minerals
Show Answer
Correct Answer: d) Conduction of water and minerals
Explanation: Epidermal tissue system primarily functions in protection, prevention of water loss (cuticle), and gaseous exchange (stomata). Conduction of water and minerals is the primary function of vascular tissue system (xylem), not epidermal tissue.
Q75. Cork cambium is also known as:
a) Phelloderm
b) Phellem
c) Phellogen
d) Periderm
Show Answer
Correct Answer: c) Phellogen
Explanation: Cork cambium is also known as phellogen. It is a secondary meristem that develops in the cortex region of older stems and roots and gives rise to periderm. Phellem is cork (produced outwards by phellogen), phelloderm is secondary cortex (produced inwards), and periderm is the collective term for phellogen, phellem and phelloderm.
Q76. Cork is also known as:
a) Phellogen
b) Phelloderm
c) Phellem
d) Periderm
Show Answer
Correct Answer: c) Phellem
Explanation: Cork is also known as phellem. It is a protective tissue produced outwards by cork cambium (phellogen). Cork cells are dead, suberized, and impermeable to water and gases. Phellogen is cork cambium, phelloderm is secondary cortex, and periderm is the entire protective layer.
Q77. Secondary cortex is also known as:
a) Phellogen
b) Phellem
c) Phelloderm
d) Periderm
Show Answer
Correct Answer: c) Phelloderm
Explanation: Secondary cortex is also known as phelloderm. It is a few layers of parenchyma cells produced inwards by cork cambium (phellogen). Phellem is cork, phellogen is cork cambium, and periderm is the entire protective layer. Secondary cortex is part of periderm, but phelloderm is the specific name for it.
Q78. The region of root tip just behind the root cap is:
a) Region of maturation
b) Region of elongation
c) Region of meristematic activity
d) Region of root hairs
Show Answer
Correct Answer: c) Region of meristematic activity
Explanation: The region of meristematic activity (or zone of cell division) is located just behind the root cap. This region contains actively dividing meristematic cells responsible for root growth. Region of elongation is above it, and region of maturation above that, root hairs in maturation zone, and root cap is at the very tip.
Q79. The region of root responsible for increase in root length is:
a) Region of maturation
b) Region of elongation
c) Region of meristematic activity
d) Root cap region
Show Answer
Correct Answer: b) Region of elongation
Explanation: The region of elongation is responsible for the increase in root length. Cells in this region elongate and enlarge, pushing the root tip forward through the soil. Region of meristematic activity is for cell division, maturation for differentiation and absorption, and root cap for protection.
Q80. The region of root where differentiation and maturation of cells occur is:
a) Region of elongation
b) Region of meristematic activity
c) Region of maturation
d) Root cap region
Show Answer
Correct Answer: c) Region of maturation
Explanation: The region of maturation (or differentiation) is where cells complete their differentiation into specific cell types (epidermal, cortical, vascular), and mature to perform their functions. Root hairs develop in this region for water absorption. Elongation is for length growth, meristematic for division, and root cap for protection.
Q81. Stele includes:
a) Cortex and pericycle
b) Endodermis and cortex
c) Pericycle and vascular bundles
d) Epidermis and cortex
Show Answer
Correct Answer: c) Pericycle and vascular bundles
Explanation: Stele is the central core of the stem or root, inside the endodermis. It includes pericycle, vascular bundles (xylem and phloem), pith (if present), and sometimes medullary rays. Cortex and epidermis are outside the stele. Endodermis forms the inner boundary of cortex and outer boundary of stele.
Q82. Pith is absent in roots of:
a) Monocots
b) Dicots
c) Both monocots and dicots
d) Some dicots
Show Answer
Correct Answer: d) Some dicots
Explanation: Pith is generally absent or poorly developed in dicot roots. In monocot roots, pith is usually large and well-developed, occupying the central portion of the root stele. Both monocot and dicot stems typically have pith, but roots show difference in pith presence and development.
Q83. The main conducting elements of xylem are:
a) Xylem parenchyma and xylem fibres
b) Tracheids and vessels
c) Sieve tubes and companion cells
d) Sieve cells and albuminous cells
Show Answer
Correct Answer: b) Tracheids and vessels
Explanation: Tracheids and vessels are the main conducting or transporting elements of xylem, primarily responsible for water and mineral conduction. Xylem parenchyma is for storage, xylem fibers for support. Sieve tubes and companion cells are in phloem for food transport, and sieve cells and albuminous cells are in gymnosperm phloem.
Q84. The main conducting elements of phloem in angiosperms are:
a) Tracheids and vessels
b) Sieve tubes and companion cells
c) Sieve cells and albuminous cells
d) Phloem parenchyma and phloem fibres
Show Answer
Correct Answer: b) Sieve tubes and companion cells
Explanation: Sieve tubes and companion cells are the main conducting elements of phloem in angiosperms, responsible for food translocation. In gymnosperms and pteridophytes, sieve cells and albuminous cells are the conducting elements of phloem. Phloem parenchyma is for storage, phloem fibers for support.
Q85. Which of the following is a living mechanical tissue?
a) Parenchyma
b) Collenchyma
c) Sclerenchyma
d) Xylem parenchyma
Show Answer
Correct Answer: b) Collenchyma
Explanation: Collenchyma is considered a living mechanical tissue because its cells are living at maturity and provide mechanical support along with flexibility. Sclerenchyma is a mechanical tissue, but its cells are dead at maturity. Parenchyma is a living tissue but primarily for storage and photosynthesis, not primarily mechanical support. Xylem parenchyma is living, but more for storage and radial water conduction within xylem, not major mechanical support in plant body.
Q86. Which of the following is a dead mechanical tissue?
a) Collenchyma
b) Parenchyma
c) Sclerenchyma
d) Epidermis
Show Answer
Correct Answer: c) Sclerenchyma
Explanation: Sclerenchyma is a dead mechanical tissue because its cells are dead at maturity and have thick, lignified cell walls providing rigidity, strength, and mechanical support. Collenchyma and parenchyma are living tissues. Epidermis is primarily protective and cells are living.
Q87. Trichomes are epidermal outgrowths found on:
a) Roots
b) Stems
c) Leaves
d) Fruits
Show Answer
Correct Answer: b) Stems
Explanation: Trichomes are multicellular epidermal outgrowths typically found on stems and leaves (shoot system). They can be branched or unbranched, soft or stiff, secretory or non-secretory, and help in preventing transpiration and insect attack. Root hairs are unicellular root epidermal extensions, not termed trichomes.
Q88. Root hairs are epidermal outgrowths found in:
a) Region of meristematic activity
b) Region of elongation
c) Region of maturation
d) Root cap region
Show Answer
Correct Answer: c) Region of maturation
Explanation: Root hairs are unicellular, thin-walled extensions of epidermal cells found in the region of maturation (differentiation) of roots. They greatly increase the surface area for absorption of water and minerals from the soil. Other root regions are not primarily associated with root hair development.
Q89. The cells of cork are:
a) Living and thin-walled
b) Living and thick-walled
c) Dead and suberized
d) Dead and lignified
Show Answer
Correct Answer: c) Dead and suberized
Explanation: Cork cells (phellem cells) are dead at maturity and their cell walls are heavily thickened and suberized (deposition of suberin). Suberin makes cork impermeable to water and gases, providing protective function. Collenchyma cells are living and thick-walled (but not suberized/lignified), parenchyma are living and thin-walled, and sclerenchyma (fibers and sclereids) are dead and lignified but not termed cork cells.
Q90. The hard gritty texture of pear fruit is due to presence of:
a) Parenchyma cells
b) Collenchyma cells
c) Sclerenchyma fibers
d) Sclereids
Show Answer
Correct Answer: d) Sclereids
Explanation: The hard, gritty texture of pear fruit and pulp of guava is due to the presence of sclereids (stone cells), a type of sclerenchyma cell. Sclereids are short, isodiametric with thick, lignified walls, providing hardness and grit. Parenchyma is soft, collenchyma is flexible, and sclerenchyma fibers are elongated, but sclereids are specifically for gritty texture.
Q91. Bast fibers are:
a) Xylem fibers
b) Phloem fibers
c) Cortical fibers
d) Epidermal fibers
Show Answer
Correct Answer: b) Phloem fibers
Explanation: Bast fibers are also known as phloem fibers. These are sclerenchyma fibers associated with phloem tissue, providing mechanical strength to phloem and stem. Xylem fibers are in xylem, cortical fibers are in cortex, and epidermal fibers is not a standard term. Bast fibers are economically important for their strength and use in textiles and ropes (e.g., jute, flax).
Q92. Wood is actually:
a) Primary xylem
b) Secondary xylem
c) Primary phloem
d) Secondary phloem
Show Answer
Correct Answer: b) Secondary xylem
Explanation: Wood is mainly composed of secondary xylem. Secondary xylem is produced by vascular cambium during secondary growth, contributing to the increase in girth of stems and roots in woody plants. Primary xylem is formed during primary growth, and primary and secondary phloem are involved in food transport, not the bulk of wood.
Q93. Bark includes:
a) Periderm only
b) Secondary phloem only
c) Periderm and secondary phloem
d) Periderm, secondary phloem and vascular cambium
Show Answer
Correct Answer: c) Periderm and secondary phloem
Explanation: Bark is a non-technical term referring to all tissues outside the vascular cambium in a woody stem or root, including periderm (cork, cork cambium, secondary cortex) and secondary phloem. Vascular cambium is inside the bark, and primary phloem and xylem are also internal to bark.
Q94. Heartwood is characterized by:
a) Presence of living xylem parenchyma cells
b) Deposition of tannins, resins, oils, etc., and non-functional xylem
c) Active water conduction
d) Abundant secondary phloem
Show Answer
Correct Answer: b) Deposition of tannins, resins, oils, etc., and non-functional xylem
Explanation: Heartwood is the central, older part of secondary xylem in woody stems. It is characterized by deposition of organic compounds like tannins, resins, oils, gums, etc., in xylem vessels and tracheids, making it hard, durable, and resistant to decay. Heartwood is non-functional for water conduction, which is mainly done by sapwood.
Q95. Sapwood is characterized by:
a) Deposition of tannins and resins
b) Non-functional xylem elements
c) Active water and mineral conduction
d) Hard and durable wood
Show Answer
Correct Answer: c) Active water and mineral conduction
Explanation: Sapwood is the peripheral, younger part of secondary xylem in woody stems, surrounding heartwood. It is involved in active conduction of water and minerals from roots to leaves. Sapwood is lighter in color and less durable than heartwood because it lacks the deposits of organic compounds found in heartwood.
Q96. Annual rings are formed due to the activity of:
a) Cork cambium
b) Vascular cambium
c) Apical meristem
d) Lateral meristem
Show Answer
Correct Answer: b) Vascular cambium
Explanation: Annual rings (growth rings) are formed in woody stems and roots due to the seasonal activity of vascular cambium. Differential activity of vascular cambium in different seasons (e.g., spring and autumn) results in distinct concentric rings of secondary xylem, which can be used to estimate the age of the tree (dendrochronology). Cork cambium forms periderm, apical and lateral meristems are for primary growth.
Q97. Diffuse porous wood is characterized by:
a) Vessels of uniform size distributed evenly throughout the wood
b) Vessels larger in springwood and smaller in autumn wood
c) Absence of vessels
d) Presence of only tracheids
Show Answer
Correct Answer: a) Vessels of uniform size distributed evenly throughout the wood
Explanation: Diffuse porous wood (or non-porous wood) is a type of wood in which vessels are of uniform size and are evenly distributed throughout the wood, throughout the annual ring. Ring porous wood has vessels of different sizes in springwood and autumn wood, creating rings of pores. Gymnosperms typically lack vessels and have tracheids only.
Q98. Ring porous wood is characterized by:
a) Vessels of uniform size
b) Vessels larger in springwood and smaller in autumn wood
c) Absence of vessels
d) Uniform distribution of vessels
Show Answer
Correct Answer: b) Vessels larger in springwood and smaller in autumn wood
Explanation: Ring porous wood is a type of wood in which vessels formed in springwood (earlywood) are larger and wider, while vessels formed in autumn wood (latewood) are smaller and narrower, creating distinct rings of pores visible to the naked eye. Diffuse porous wood has uniform vessel size.
Q99. Duramen is another name for:
a) Sapwood
b) Heartwood
c) Cork
d) Cambium
Show Answer
Correct Answer: b) Heartwood
Explanation: Duramen is another name for heartwood. Both terms refer to the central, older, darker, harder, and non-conducting part of secondary xylem, impregnated with tannins, resins, etc. Alburnum is another name for sapwood (peripheral and conducting xylem), phellem for cork, and phellogen for cork cambium.
Q100. Alburnum is another name for:
a) Heartwood
b) Sapwood
c) Phelloderm
d) Phellogen
Show Answer
Correct Answer: b) Sapwood
Explanation: Alburnum is another name for sapwood. Both terms denote the peripheral, younger, lighter colored, softer, and conducting part of secondary xylem, involved in active water and mineral transport. Duramen is heartwood, phelloderm is secondary cortex, and phellogen is cork cambium.