Which type of pollination involves the transfer of pollen from the anther to the stigma of another flower on the same plant?
- Autogamy
- Cleistogamy
- Geitonogamy
- Xenogamy
Explanation: Geitonogamy is functionally cross-pollination involving a pollinating agent, but genetically it is similar to autogamy since the pollen comes from the same plant.
The symbiotic relationship between the Pronuba moth and the Yucca plant is a classic example of:
- Parasitism
- Water pollination
- Obligate pollination
- Wind pollination
Explanation: The moth and the plant cannot complete their life cycles without each other; the moth deposits eggs in the ovary and pollinates the flower.
Which hormone is commonly used to induce 'Parthenocarpy' in fruits like tomatoes?
- Auxins
- Cytokinins
- Abscisic acid
- Ethylene
Explanation: Parthenocarpy (production of fruit without fertilization) can be induced through the application of growth hormones like auxins and gibberellins.
Which of the following is an example of an 'Epigynous' flower where the fruit is a false fruit?
Explanation: In apple, the thalamus grows to enclose the ovary and becomes the fleshy edible part, making it a false fruit.
The small pore in the seed coat through which oxygen and water enter during germination is the:
- Hilum
- Chalaza
- Raphe
- Micropyle
Explanation: The micropyle remains as a small pore in the seed coat, facilitating the entry of water and oxygen into the seed for germination.
Regarding pollen-pistil interaction, the ability of the pistil to recognize the pollen is based on:
- Chemical components
- Physical size
- Color of pollen
- Pollen weight
Explanation: The recognition is mediated by chemical components of the pollen interacting with those of the pistil.
Regarding 'Monosporic' development of the embryo sac, it implies that the embryo sac develops from:
- Four megaspores
- Two megaspores
- Microspore mother cell
- Single megaspore
Explanation: In a majority of flowering plants, one of the megaspores is functional while the other three degenerate. Only the functional megaspore develops into the female gametophyte.
Statement I: Cleistogamous flowers produce assured seed-set even in the absence of pollinators.
Statement II: Cleistogamous flowers never open at all.
- Statement II correct
- Statement I correct
- Both are correct
- Both are incorrect
Explanation: Since the flowers remain closed, self-pollination is guaranteed, making them independent of external pollinators for seed production.
Which scientist is credited with the discovery of 'Double Fertilization' in Lilium and Fritillaria?
- Strasburger
- Maheshwari
- Hofmeister
- Nawaschin
Explanation: S.G. Nawaschin (1898) first observed the dual fusion events that characterize double fertilization in angiosperms.
What is the typical cellular and nuclear composition of a mature angiosperm embryo sac?
- 8-celled, 7-nucleate
- 7-celled, 8-nucleate
- 7-celled, 7-nucleate
- 8-celled, 8-nucleate
Explanation: Though there are 8 nuclei (3 antipodal, 2 polar, 1 egg, 2 synergid), the two polar nuclei are situated in one large central cell, making it a 7-celled structure.
In 'Entomophilous' (insect-pollinated) flowers, the pollen grains are characteristically:
- Small and smooth
- Light and dry
- Sticky and heavy
- Large and winged
Explanation: Insect-pollinated pollen grains are usually sticky (due to a pollen kit) so they can easily adhere to the body of the visiting insect.
Which hormone is primarily responsible for the 'ripening' of the ovary into a fruit?
- Cytokinin
- Gibberellin
- Ethylene
- Abscisic acid
Explanation: Ethylene is the gaseous plant hormone that coordinates the various physiological changes during the ripening of fruits.
The 'Scutellum' in a grass embryo is morphologically equivalent to the:
- Radicle
- Hypocotyl
- Plumule
- Cotyledon
Explanation: The single, shield-shaped cotyledon in monocotyledons (specifically the grass family) is called the scutellum.
The 'Coconut water' from a tender coconut represents which type of endosperm?
- Cellular endosperm
- Free-nuclear endosperm
- Helobial endosperm
- Solid endosperm
Explanation: Coconut water is free-nuclear endosperm made up of thousands of nuclei. The surrounding white kernel is the cellular endosperm.
Which part of the ovule develops into the seed coat after fertilization?
- Funicle
- Integuments
- Chalaza
- Nucellus
Explanation: The integuments of the ovule harden to form the tough protective seed coat (testa and tegmen).
Which of the following describes the 'ploidy' level of the Nucellus, PMC, and Endosperm respectively?
- 2n, 2n, 3n
- n, n, 3n
- 2n, n, 3n
- 3n, 2n, n
Explanation: Nucellus and Pollen Mother Cell (PMC) are diploid (2n) tissues, while the Endosperm is triploid (3n) resulting from triple fusion.
The 'Seed dormancy' is a state of metabolic inactivity that is primarily triggered by:
- High temperatures
- Loss of moisture
- Increase in oxygen
- Water absorption
Explanation: As the seed matures, its water content is reduced (to 10-15% moisture by mass), leading to a state of inactivity called dormancy.
The most resistant part of the plant kingdom, which can be preserved as fossils for millions of years, is the:
- Pollen exine
- Embryo sac
- Endosperm
- Nucellus
Explanation: Because of the presence of sporopollenin in the exine, pollen grains are very well preserved as fossils.
Which specific cell of the pollen grain is responsible for giving rise to the two male gametes?
- Tapetal cell
- Vegetative cell
- Generative cell
- Nucellar cell
Explanation: The generative cell is small and floats in the cytoplasm of the vegetative cell; it divides mitotically to form the two male gametes.
Which of the following is an 'Outbreeding device' used by plants to prevent self-pollination?
- Cleistogamy
- Self-incompatibility
- Synchrony in release
- Homogamy
Explanation: Self-incompatibility is a genetic mechanism that prevents self-pollen from fertilizing the ovules by inhibiting pollen germination.
In 'Artificial Hybridization', the removal of anthers from the flower bud before they dehisce is called:
- Tagging
- Re-bagging
- Emasculation
- Bagging
Explanation: Emasculation is the process of removing anthers from bisexual flowers to prevent self-pollination in plant breeding experiments.
The 'Filiform apparatus' is a characteristic feature found in which part of the embryo sac?
- Egg cell
- Antipodal cells
- Synergids
- Central cell
Explanation: Synergids have special cellular thickenings at the micropylar tip called the filiform apparatus, which plays an important role in guiding the pollen tube into the synergid.
A seed of which plant was recently germinated after 2000 years of dormancy near the Dead Sea?
- Phoenix dactylifera
- Nelumbo nucifera
- Lodoicea maldivica
- Lupinus arcticus
Explanation: A viable seed of the date palm, Phoenix dactylifera, was discovered during archeological excavation at King Herod's palace near the Dead Sea.
In the process of 'Double Fertilization', the 'Triple Fusion' results in the formation of:
- Synergid
- Zygote
- Antipodal nucleus
- Primary Endosperm Nucleus
Explanation: Triple fusion involves the fusion of one male gamete with two polar nuclei to produce the triploid Primary Endosperm Nucleus (PEN).
The 'Perisperm', which is the persistent remnant of the nucellus, is found in which of the following?
- Castor and Coconut
- Black pepper
- Pea and Bean
- Maize and Wheat
Explanation: In some seeds such as black pepper and beet, remnants of nucellus are also persistent. This residual, persistent nucellus is the perisperm.
In a 'Three-celled' pollen grain, the generative cell has already divided into:
- Four microspores
- Two male gametes
- Two vegetative cells
- Two polar nuclei
Explanation: In some species, the generative cell divides into two male gametes while the pollen is still in the anther, making it a 3-celled grain at dehiscence.
The entry of the pollen tube through the 'Micropyle' of the ovule is termed as:
- Siphonogamy
- Chalazogamy
- Mesogamy
- Porogamy
Explanation: Porogamy is the most common route where the pollen tube enters the ovule through the micropylar opening.
In 'Albuminous' (Endospermic) seeds, the endosperm is:
- Converted to fruit
- Completely consumed
- Absent throughout
- Partially retained
Explanation: Albuminous seeds (e.g., Wheat, Maize, Castor) retain a part of the endosperm as it is not completely used up during embryo development.
The 'Stomium' is a specialized region of the anther wall involved in which process?
- Microspore division
- Pollen nourishment
- Pollen protection
- Anther dehiscence
Explanation: The stomium is the part of the anther wall (usually in the endothecium) that ruptures to release the mature pollen grains.
Which of the following is a dioecious plant where autogamy is strictly prevented?
- Cucumber
- Castor
- Papaya
- Maize
Explanation: In Papaya, male and female flowers are on different plants (dioecious), preventing both autogamy and geitonogamy.
The process of 'Apomixis' is biologically significant because it represents:
- Delayed fertilization
- Sexual mimicking asexual
- Multiple embryo formation
- Asexual mimicking sexual
Explanation: Apomixis is a form of asexual reproduction that mimics sexual reproduction, where seeds are produced without fertilization.
What happens to the polar nuclei after they are fused with the second male gamete?
- Form embryo
- Form zygote
- Form endosperm
- Degenerate
Explanation: The fusion of the second male gamete with the two polar nuclei forms the primary endosperm nucleus, which develops into the nutrient-rich endosperm.
In 'Dioecious' plants like Papaya, which types of pollination are prevented?
- Autogamy only
- Geitonogamy only
- Xenogamy only
- Both above
Explanation: Since male and female flowers are on separate plants, neither self-pollination of a flower (autogamy) nor pollination between flowers of the same plant (geitonogamy) is possible.
The wall of the fruit that develops from the wall of the ovary is called the:
- Seed coat
- Perisperm
- Placenta
- Pericarp
Explanation: The pericarp is the fruit wall, which can be fleshy (as in guava/orange) or dry (as in mustard/groundnut).
Which cells in the embryo sac are located at the chalazal end?
- Polar nuclei
- Egg cell
- Antipodals
- Synergids
Explanation: The three cells at the chalazal end are called the antipodals. The egg apparatus (egg + synergids) is at the micropylar end.
The 'Basal' part of the ovule where the integuments originate is called the:
- Hilum
- Chalaza
- Funicle
- Micropyle
Explanation: Opposite the micropylar end is the chalaza, representing the basal part of the ovule.
Regarding 'Polyembryony', the extra embryos in Citrus species often arise from:
- Synergid cells
- Central cell
- Nucellar cells
- Antipodal cells
Explanation: In many Citrus and Mango varieties, nucellar cells surrounding the embryo sac start dividing and protrude into the embryo sac to develop into embryos.
In 'Hydrophily' (water pollination), the pollen grains are often protected from wetting by a:
- Waxy cuticle
- Thick exine
- Mucilaginous covering
- Protein coat
Explanation: Pollen grains in many water-pollinated species are long and ribbon-like and are covered by a mucilaginous layer to prevent them from becoming waterlogged.
The 'Germ pores' in the pollen grain exine are locations where:
- Pollen is attached
- Nucleus is located
- Intine is thickest
- Sporopollenin is absent
Explanation: Germ pores are prominent apertures in the exine where sporopollenin is absent, allowing for the emergence of the pollen tube.
The 'Epicotyl' is the portion of the embryonic axis located specifically:
- Inside radicle
- Outside seed
- Below cotyledons
- Above cotyledons
Explanation: The portion of the embryonic axis above the level of cotyledons is the epicotyl, which terminates with the plumule.
Flowers that do not open at all, ensuring self-pollination even in the absence of pollinators, are called:
- Cleistogamous
- Hydrophilous
- Chasmogamous
- Anemophilous
Explanation: Cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma. They produce assured seed-set even without pollinators.
Which of the following plants produces 'True fruits'?
- Apple
- Mango
- Cashew
- Strawberry
Explanation: In mango, the fruit develops only from the ovary. In apple, strawberry, and cashew, the thalamus also contributes to fruit formation (False fruits).
The occurrence of more than one embryo in a seed, common in Citrus and Mango, is termed:
- Parthenogenesis
- Polyembryony
- Apomixis
- Dichogamy
Explanation: Polyembryony occurs when multiple embryos develop in a single seed, often due to nucellar cells dividing and protruding into the embryo sac.
The persistent wall of the megasporangium that encloses the embryo sac is called the:
- Integument
- Endosperm
- Nucellus
- Pericarp
Explanation: The nucellus is a mass of parenchymatous cells enclosed within the integuments which have abundant reserve food materials.
Which of the following is a 'Water-soluble' pigment found in the vacuoles of flower petals to attract insects?
- Xanthophylls
- Carotenoids
- Anthocyanins
- Chlorophyll
Explanation: Anthocyanins provide red, purple, and blue colors to flowers and fruits and are stored in the cell vacuoles.
The 'Exine' of a pollen grain is composed of which highly resistant organic material?
- Pectin
- Lignin
- Cellulose
- Sporopollenin
Explanation: Sporopollenin is one of the most resistant organic materials known. It can withstand high temperatures, strong acids, and alkalis, and no enzyme is known to degrade it.
How many 'Meiotic' divisions are required to produce 100 seeds in a typical angiosperm?
Explanation: 100 seeds require 100 male gametes (from 25 meiosis in microspores) and 100 eggs (from 100 meiosis in megaspores). Total = 125.
Statement I: Non-albuminous seeds have no residual endosperm.
Statement II: Endosperm is completely consumed during embryo development.
- Statement I correct
- Statement II correct
- Both are correct
- Both are incorrect
Explanation: In non-albuminous seeds (e.g., Pea, Groundnut), the endosperm is fully utilized during development. (A/R format avoided per instructions).
The 'Integumentary' covering of the ovule eventually hardens to form the:
- Seed coat
- Endosperm
- Pericarp
- Coleoptile
Explanation: After fertilization, the outer and inner integuments dry and harden to form the testa and tegmen of the seed coat.
Which of the following parts of the flower is primarily used as a platform for the landing of pollen grains?
- Style
- Stigma
- Anther
- Ovary
Explanation: The stigma serves as the receptive surface for the landing and germination of pollen grains.
The phenomenon where the pollen of a flower fails to germinate on the stigma of the same flower is called:
- Artificial hybridization
- Self-incompatibility
- Emasculation
- Triple fusion
Explanation: Self-incompatibility is a genetic mechanism that prevents self-pollen from fertilizing the ovules by inhibiting pollen germination or pollen tube growth in the pistil.
In an 'Anatropous' ovule, which is the most common type in angiosperms, the body of the ovule is:
- Curved horizontally
- Inverted downwards
- Completely straight
- Partially tilted
Explanation: An anatropous ovule is completely inverted so that the micropyle lies close to the hilum and the funiculus.
Which of the following is a classic example of a plant where pollination is achieved by water?
- Water hyacinth
- Lotus
- Vallisneria
- Water lily
Explanation: In Vallisneria, the female flower reaches the surface of the water by a long stalk, and male flowers or pollen grains are released onto the surface. Water lily and hyacinth are insect/wind pollinated.
Wind-pollinated flowers are characterized by having which of the following features?
- Feathery stigma
- Large colorful petals
- Sticky pollen grains
- Strong floral scent
Explanation: Wind-pollinated (anemophilous) flowers often have well-exposed stamens and large feathery stigmas to easily trap air-borne pollen grains.
Which part of the embryo sac usually degenerates immediately after the process of fertilization?
- Central cell
- Synergids
- Zygote
- Endosperm
Explanation: Synergids and antipodal cells degenerate after fertilization. The zygote develops into the embryo, and the central cell becomes the endosperm.
Which specific layer of the microsporangium provides nourishment to the developing pollen grains?
- Middle layers
- Epidermis
- Tapetum
- Endothecium
Explanation: The tapetum is the innermost layer. Its cells possess dense cytoplasm and usually have more than one nucleus to nourish the developing microspores.
In over 60 percent of angiosperms, pollen grains are shed at which specific stage?
- Single-celled
- Four-celled
- Two-celled
- Three-celled
Explanation: In most angiosperms, the pollen is shed at the two-celled stage (vegetative cell and generative cell). In others, the generative cell divides into two male gametes before shedding (three-celled stage).
The 'Pollen-pistil interaction' is best described as a/an:
- Dynamic chemical dialogue
- Electrical signaling
- Automatic mechanical process
- Physical barrier
Explanation: It involves the recognition of pollen followed by promotion or inhibition, mediated by chemical components of the pollen and the pistil.
What is the primary advantage of 'Apomictic' seeds in the agricultural industry?
- Genetic variation
- Hybrid vigor maintenance
- Rapid mutation
- Cross-pollination
Explanation: If hybrids are made into apomicts, there is no segregation of characters in the progeny, allowing farmers to reuse seeds without losing hybrid traits.
Which structure protects the young plumule in a monocotyledonous embryo?
- Epiblast
- Scutellum
- Coleorhiza
- Coleoptile
Explanation: In monocots, the plumule and leaf primordia are enclosed in a hollow foliar structure called the coleoptile.