Sexual Reproduction in Flowering Plants MCQ Class 12

Correct Answer: C. Sexual reproduction. Flowers are the primary reproductive organs in angiosperms, responsible for facilitating sexual reproduction.

Correct Answer: A. Stem. While flowers are borne on stems, the stem itself is not considered a direct part of the flower.

Correct Answer: A. Inflorescence. An inflorescence refers to the arrangement of flowers on the floral axis of a plant.

Correct Answer: B. Ovary. The ovary, typically located at the base of the pistil, develops into the fruit after fertilisation.

Correct Answer: C. Pollinator attraction. The vibrant colors of petals serve to attract pollinators like insects and birds, aiding in the process of sexual reproduction.

Correct Answer: A. Sepal. Sepals are the outermost, leaf-like parts of a flower that primarily protect the developing bud and are not directly involved in sexual reproduction.

Correct Answer: C. Perfect. A flower containing both stamen and pistil is referred to as a perfect flower.

Correct Answer: A. Colorful petals. Wind-pollinated flowers typically lack showy petals as they don’t rely on attracting pollinators.

Correct Answer: B. Pollination. Pollination is the process of transferring pollen grains from the anther (male part) to the stigma (female part) of a flower.

Correct Answer: C. Insect. Insects are biotic (living) agents that play a crucial role in pollinating many flowering plants.

Correct Answer: A. Ovule. The ovule, present within the ovary, contains the female reproductive cell and develops into the seed after fertilisation.

Correct Answer: D. Small, inconspicuous flowers. Insect-pollinated flowers tend to be larger and more conspicuous to attract insects.

Correct Answer: B. Geitonogamy. Geitonogamy refers to the transfer of pollen grains from the anther of one flower to the stigma of another flower on the same plant.

Correct Answer: C. Autogamy. Autogamy is self-pollination, which is the opposite of strategies to prevent self-pollination.

Correct Answer: D. Pollen-pistil interaction. The process of pollen tube entry into the ovule through the micropyle is part of the broader pollen-pistil interaction.

Correct Answer: B. Monoecious. A monoecious plant has separate male and female flowers on the same individual.

Correct Answer: D. Cleistogamy. Cleistogamy refers to the production of flowers that do not open, promoting self-pollination rather than cross-pollination.

Correct Answer: A. Palynology. Palynology is the study of pollen grains and other spores, particularly those found in fossil records.

Correct Answer: B. Anther. The male gametophyte, or pollen grain, develops within the anther of the flower.

Correct Answer: B. Stamen. The stamen is the male reproductive organ of a flower, responsible for producing pollen.

Correct Answer: B. Anther and filament. The stamen consists of the anther, which produces pollen, and the filament, which supports the anther.

Correct Answer: B. Anther. The anther contains the microsporangia, where pollen grains are produced.

Correct Answer: B. Two. An anther typically has two lobes, each containing two microsporangia.

Correct Answer: B. Microsporogenesis. Microsporogenesis is the process by which microspores, which develop into pollen grains, are formed.

Correct Answer: B. Exine. The exine is the tough, outer layer of the pollen grain wall, often ornamented and resistant to decay.

Correct Answer: A. Protection from desiccation. The exine, not the intine, provides protection from desiccation. The intine is involved in pollen tube formation and other functions.

Correct Answer: C. Germ pores. Germ pores are apertures in the exine that allow for the emergence of the pollen tube during germination.

Correct Answer: B. Viability. Pollen viability refers to the duration for which a pollen grain remains capable of germinating.

Correct Answer: D. Sporopollenin. Sporopollenin is a major component of the exine and is a common allergen for many people.

Correct Answer: C. Allergy medication. While pollen is a source of allergens, it is not used in allergy medication. It is used in other applications like food supplements, forensic studies, and paleontological research.

Correct Answer: C. Nourishment. The tapetum is the innermost layer of the microsporangium and provides nourishment to the developing pollen grains.

Correct Answer: B. Diploid. The microspore mother cell is a diploid cell that undergoes meiosis to produce haploid microspores.

Correct Answer: D. Four. Meiosis in the microspore mother cell results in the formation of four haploid microspores.

Correct Answer: A. Haploid. A mature pollen grain is the male gametophyte and is haploid.

Correct Answer: C. Highly resistant to degradation. The exine is composed of sporopollenin, making it extremely resistant to degradation.

Correct Answer: A. Pistil. The pistil is the female reproductive organ of a flower, responsible for producing ovules.

Correct Answer: A. A modified leaf that forms part of the pistil. A carpel is the basic unit of the pistil and is a modified leaf that encloses the ovules.

Correct Answer: B. Syncarpous. A syncarpous gynoecium has multiple carpels fused together.

Correct Answer: B. Stigma, style, and ovary. The pistil comprises the stigma, which receives pollen, the style, which connects the stigma to the ovary, and the ovary, which contains the ovules.

Correct Answer: B. Pollen reception. The stigma is the receptive surface of the pistil where pollen grains land and germinate.

Correct Answer: C. Ovary. The ovary is the basal, swollen part of the pistil that contains the ovules.

Correct Answer: A. Funicle. The funicle is a stalk-like structure that connects the ovule to the placenta within the ovary.

Correct Answer: C. Micropyle. The micropyle is a small opening in the integuments of the ovule through which the pollen tube enters.

Correct Answer: A. Megasporogenesis. Megasporogenesis is the process by which megaspores are formed within the ovule.

Correct Answer: A. One. Typically, only one of the four megaspores produced during megasporogenesis is functional and develops into the embryo sac.

Correct Answer: A. Monosporic. Monosporic development, where the embryo sac develops from a single megaspore, is the most common type in angiosperms.

Correct Answer: C. Seven. A mature embryo sac is typically seven-celled, consisting of the egg apparatus, the central cell, and the antipodals.

Correct Answer: A. Two synergids and one egg cell. The egg apparatus is located at the micropylar end of the embryo sac and consists of two synergids and one egg cell.

Correct Answer: B. Fusion with a sperm cell to form the endosperm. The two polar nuclei in the central cell fuse with a sperm cell during double fertilisation to form the endosperm.

Correct Answer: B. Pollination. Pollination is the process of transferring pollen grains from the anther to the stigma.

Correct Answer: A. Autogamy. Autogamy refers to self-pollination within the same flower.

Correct Answer: B. Geitonogamy. Geitonogamy is the transfer of pollen between different flowers on the same plant.

Correct Answer: C. Xenogamy. Xenogamy refers to cross-pollination between flowers on different plants.

Correct Answer: C. Insects. Insects are biotic pollinators, while wind, water, and gravity are abiotic agents.

Correct Answer: D. Abundant, light pollen grains. Wind-pollinated flowers produce large amounts of lightweight pollen for easy dispersal by wind.

Correct Answer: D. Large, colorful petals. Water-pollinated flowers generally have inconspicuous petals as they do not need to attract pollinators.

Correct Answer: C. Small, inconspicuous flowers. Entomophilous flowers are typically large and showy to attract insects.

Correct Answer: C. Self-incompatibility. Self-incompatibility is a mechanism that prevents pollen from the same flower or plant from fertilizing the ovule.

Correct Answer: B. Dichogamy. Dichogamy is a temporal separation in the maturation of anthers and stigma to avoid self-pollination.

Correct Answer: B. Pollen tube growth. After landing on the stigma, the pollen grain germinates and the pollen tube grows through the style towards the ovule.

Correct Answer: A. Pollen-pistil interaction. Pollen-pistil interaction involves a series of events that ensure compatible pollen grains are recognized and allowed to germinate.

Correct Answer: B. Emasculation. Emasculation is the removal of anthers from bisexual flowers to prevent self-pollination.

Correct Answer: A. Bagging. Bagging is done to prevent pollination by unwanted pollen after emasculation.

Correct Answer: C. To promote cross-pollination between selected parents. Artificial hybridization is a controlled pollination technique used to create offspring with desired traits from specific parent plants.

Correct Answer: B. Double fertilisation. Angiosperms are characterized by double fertilisation, involving two fusion events.

Correct Answer: A. Syngamy. Syngamy is the fusion of a sperm cell with the egg cell, resulting in the formation of a zygote.

Correct Answer: B. Triple fusion. Triple fusion involves the fusion of the second sperm cell with the two polar nuclei in the central cell of the embryo sac.

Correct Answer: A. Zygote. Syngamy results in the formation of a diploid zygote, which develops into the embryo.

Correct Answer: B. Endosperm. Triple fusion leads to the formation of the triploid endosperm, which provides nourishment to the developing embryo.

Correct Answer: C. Endosperm. The endosperm is a nutritive tissue that provides food for the developing embryo.

Correct Answer: D. Free-nuclear endosperm. Free-nuclear endosperm development is the most common type, where the endosperm nucleus divides repeatedly without cell wall formation.

Correct Answer: B. Cellular endosperm. In cellular endosperm development, cell wall formation accompanies each nuclear division.

Correct Answer: C. Helobial endosperm. Helobial endosperm shows characteristics of both nuclear and cellular types.

Correct Answer: C. Triploid. The endosperm is formed by the fusion of a sperm cell (haploid) with two polar nuclei (each haploid), resulting in a triploid nucleus.

Correct Answer: C. Providing nutrition to the developing embryo. The endosperm serves as a food reserve for the growing embryo.

Correct Answer: A. Embryogenesis. Embryogenesis is the process by which the embryo develops from the zygote.

Correct Answer: A. Transverse. The first cell division of the zygote is typically transverse.

Correct Answer: C. Plumule and radicle. A dicot embryo consists of the plumule (shoot apex) and the radicle (root apex).

Correct Answer: A. Scutellum. The scutellum is the single cotyledon in a monocot embryo, which absorbs nutrients from the endosperm.

Correct Answer: A. Seed. The seed is the mature ovule that contains the embryo and stored food.

Correct Answer: A. Seed coat. The seed coat is the tough, outer layer that protects the seed from damage and desiccation.

Correct Answer: C. Cotyledons. Cotyledons are the embryonic leaves that store food reserves in some seeds.

Correct Answer: C. Embryo axis. The embryo axis is the central axis of the embryo that connects the radicle and plumule.

Correct Answer: B. Non-albuminous. Non-albuminous seeds have exhausted their endosperm during embryo development, with food reserves stored in the cotyledons.

Correct Answer: A. Albuminous. Albuminous seeds retain a significant portion of the endosperm at maturity.

Correct Answer: B. Dormancy. Seed dormancy is a state of temporary metabolic inactivity that prevents premature germination.

Correct Answer: A. Germination. Germination is the resumption of growth and development in a seed under favorable conditions.

Correct Answer: B. Fruit. The fruit is the mature ovary that develops after fertilisation, often containing seeds.

Correct Answer: C. Pericarp. The pericarp is the fruit wall that develops from the ovary wall and can be differentiated into layers like exocarp, mesocarp, and endocarp.

Correct Answer: B. False fruit. A false fruit develops from the ovary along with other floral parts, such as the thalamus.

Correct Answer: C. Parthenocarpic fruit. Parthenocarpic fruits develop without fertilisation and are seedless.

Correct Answer: B. Banana. Bananas are a common example of parthenocarpic fruits, developing without fertilisation.

Correct Answer: A. Seed dispersal. Fruits play a crucial role in protecting and dispersing seeds to new locations.

Correct Answer: A. Apomixis. Apomixis is a form of asexual reproduction in which seeds are produced without fertilisation.

Correct Answer: C. Polyembryony. Polyembryony is the occurrence of multiple embryos within a single seed.

Correct Answer: B. Increased genetic diversity. Apomixis leads to genetically uniform offspring, thus reducing genetic diversity.

Correct Answer: B. Citrus fruits. Citrus fruits often exhibit polyembryony, with multiple embryos developing within a single seed.

Correct Answer: C. Parthenogenesis. Parthenogenesis is a type of apomixis in which the embryo develops from an unfertilized egg cell.

Correct Answer: D. Adventitious embryony. In adventitious embryony, the embryo develops directly from a diploid cell of the nucellus or integument.

Correct Answer: D. Enhancement of fruit size and quality. While apomixis has several applications, it may not directly enhance fruit size and quality.