NCERT - SEXUAL REPRODUCTION IN FLOWERING PLANTS - 2 - 24 - 25
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Questions and Answers

What is the function of the filiform apparatus in synergids?

  • To produce gametes
  • To guide pollen tubes into the synergid (correct)
  • To protect the embryo sac
  • To attract pollinators

    • Autogamy allows for pollination within different flowers.

    False

    What are the two types of flowers produced by plants like Viola and Oxalis for autogamy?

    Chasmogamous and cleistogamous flowers

    Pollination is the transfer of pollen grains from the anther to the _____ of a pistil.

    <p>stigma</p> Signup and view all the answers

    Which of the following is a type of pollination involving the same flower?

    <p>Self-pollination</p> Signup and view all the answers

    Match the following types of pollination with their definitions:

    <p>Autogamy = Pollination within the same flower Chasmogamous flowers = Flowers that are open and expose anthers and stigma Cleistogamous flowers = Flowers that do not open Cross-pollination = Pollination involving different flowers</p> Signup and view all the answers

    The embryo sac of a typical angiosperm is 7-nucleate and 8-celled.

    <p>False</p> Signup and view all the answers

    The large central cell in the embryo sac has _____ polar nuclei.

    <p>two</p> Signup and view all the answers

    What is the purpose of dusting mature pollen grains on the stigma?

    <p>To enable pollination</p> Signup and view all the answers

    Emasculation is required when the female parent produces unisexual flowers.

    <p>False</p> Signup and view all the answers

    What is formed as a result of syngamy during double fertilization?

    <p>Zygote</p> Signup and view all the answers

    The process involving the fusion of two male gametes with one egg cell and two polar nuclei is called __________.

    <p>double fertilization</p> Signup and view all the answers

    Match the following post-fertilization events with their descriptions:

    <p>Endosperm = Tissue that nourishes the developing embryo Zygote = Develops into the embryo Ovule = Matures into seeds Ovary = Matures into fruit</p> Signup and view all the answers

    What does the primary endosperm cell develop into?

    <p>Endosperm tissue</p> Signup and view all the answers

    Triple fusion occurs between one male gamete and two polar nuclei.

    <p>True</p> Signup and view all the answers

    What event is termed double fertilization in flowering plants?

    <p>The fusion of one male gamete with the egg cell and another male gamete with two polar nuclei.</p> Signup and view all the answers

    What was Panchanan Maheshwari's primary area of expertise?

    <p>Botany</p> Signup and view all the answers

    Panchanan Maheshwari was born in Jaipur during the 20th century.

    <p>True</p> Signup and view all the answers

    Who inspired Panchanan Maheshwari to develop an interest in Botany?

    <p>Dr W. Dudgeon</p> Signup and view all the answers

    Panchanan Maheshwari established the Department of Botany, University of ______, as an important center of research.

    <p>Delhi</p> Signup and view all the answers

    Match the following achievements of Panchanan Maheshwari with their descriptions:

    <p>Embryological research = Popularised the use of embryological characters in taxonomy Tissue Culture = Initiated work on artificial culture of immature embryos Textbooks for Biology = Contributed to the first textbooks published by NCERT in 1964 Worldwide acclaim = His work on test tube fertilisation and intra-ovarian pollination</p> Signup and view all the answers

    Which institution honored Panchanan Maheshwari with a fellowship?

    <p>Royal Society of London</p> Signup and view all the answers

    All flowering plants reproduce asexually.

    <p>False</p> Signup and view all the answers

    In which year were the first textbooks of Biology for Higher Secondary Schools published by NCERT?

    <p>1964</p> Signup and view all the answers

    What is the term for seed production without fertilisation?

    <p>Apomixis</p> Signup and view all the answers

    The process of polyembryony involves only one embryo developing within a seed.

    <p>False</p> Signup and view all the answers

    Name one plant that produces a large number of seeds.

    <p>Orchid</p> Signup and view all the answers

    In some species, the diploid egg cell forms without reduction division in a process called ______.

    <p>apomixis</p> Signup and view all the answers

    Match the following terms with their descriptions:

    <p>Apomixis = Seed production without fertilization Polyembryony = Multiple embryos in a single seed Ficus = Tree that produces billions of seeds Hybrid varieties = Plants that exhibit segregation of traits in progeny</p> Signup and view all the answers

    Which flowering plants produce polyembryonic seeds?

    <p>Citrus and Mango</p> Signup and view all the answers

    Hybrid seeds collected from previous plants maintain their hybrid characteristics when re-sown.

    <p>False</p> Signup and view all the answers

    What type of seeds can develop into clones in apomixis?

    <p>Apomictic embryos</p> Signup and view all the answers

    What is the function of the endosperm during seed development?

    <p>Nutrition for the developing embryo</p> Signup and view all the answers

    Coconut water is made up of cellular endosperm.

    <p>False</p> Signup and view all the answers

    What happens to the endosperm in plants like castor and coconut during seed germination?

    <p>It persists and is used up during seed germination.</p> Signup and view all the answers

    The _______ develops at the micropylar end of the embryo sac.

    <p>embryo</p> Signup and view all the answers

    Match the following seed types with their endosperm characteristics:

    <p>Pea = Endosperm consumed before seed maturation Coconut = Endosperm persists in mature seed Groundnut = Endosperm consumed before seed maturation Castor = Endosperm persists in mature seed</p> Signup and view all the answers

    Which of the following is NOT a stage in the development of a typical dicotyledonous embryo?

    <p>Pseudocotyledon stage</p> Signup and view all the answers

    Monocotyledons have two cotyledons.

    <p>False</p> Signup and view all the answers

    The region of the embryonal axis above the level of cotyledons in a dicotyledon is called the _______.

    <p>epicotyl</p> Signup and view all the answers

    Which of the following fruits is an example of a false fruit?

    <p>Strawberry</p> Signup and view all the answers

    Parthenocarpic fruits develop only from the ovary and require fertilization.

    <p>False</p> Signup and view all the answers

    What are the advantages of seeds for angiosperms?

    <p>Seeds offer protection, nourishment for seedlings, and better dispersal strategies.</p> Signup and view all the answers

    The oldest viable seed germinated after _____ years of dormancy.

    <p>10,000</p> Signup and view all the answers

    Which statement best describes true fruits?

    <p>They develop solely from the ovary.</p> Signup and view all the answers

    What can induce parthenocarpy in fruits?

    <p>Growth hormones</p> Signup and view all the answers

    Match the following seeds with their record ages:

    <p>Lupinus arcticus = 10,000 years Phoenix dactylifera = 2,000 years Common sunflower = Several years Timber bamboo = Few months</p> Signup and view all the answers

    Seeds provide _____ that nourishes young seedlings until they can photosynthesize.

    <p>food reserves</p> Signup and view all the answers

    What are the two types of gynoecium based on the number of pistils?

    <p>Monocarpellary and Multicarpellary</p> Signup and view all the answers

    The ovule is attached to the placenta through a stalk called hilum.

    <p>False</p> Signup and view all the answers

    What is the process of formation of megaspores from the megaspore mother cell called?

    <p>megasporogenesis</p> Signup and view all the answers

    Each ovule generally has a single embryo sac formed from a __________.

    <p>megas pore</p> Signup and view all the answers

    Match the following parts of the pistil with their functions:

    <p>Stigma = Serves as a landing platform for pollen grains Style = Connects stigma to ovary Ovary = Contains ovules Placenta = Attachment point for ovules</p> Signup and view all the answers

    What is the basal part of the ovule called?

    <p>Chalaza</p> Signup and view all the answers

    Integuments encircle the nucellus at all points except at the tip.

    <p>True</p> Signup and view all the answers

    What is the elongated part of the pistil located below the stigma called?

    <p>style</p> Signup and view all the answers

    What significant contribution did Panchanan Maheshwari make in the field of education?

    <p>Developed the first textbooks of Biology for Higher Secondary Schools</p> Signup and view all the answers

    Panchanan Maheshwari's work mainly focused on plant genetics and not botany.

    <p>False</p> Signup and view all the answers

    In which year was Panchanan Maheshwari born?

    <p>1904</p> Signup and view all the answers

    Panchanan Maheshwari was honored with the fellowship of the Royal Society of ______.

    <p>London</p> Signup and view all the answers

    Which area of plant science did Panchanan Maheshwari particularly emphasize?

    <p>Tissue culture and embryology</p> Signup and view all the answers

    Name the place where Panchanan Maheshwari was born.

    <p>Jaipur</p> Signup and view all the answers

    What structure is typically found at the corners of an anther?

    <p>Microsporangia</p> Signup and view all the answers

    The innermost layer of the anther wall is called the endothecium.

    <p>False</p> Signup and view all the answers

    What happens to the sporogenous tissue as the anther develops?

    <p>Undergoes meiotic divisions to form microspore tetrads.</p> Signup and view all the answers

    A typical angiosperm anther is ______ and consists of four microsporangia.

    <p>bilobed</p> Signup and view all the answers

    Match the components of an anther with their functions:

    <p>Epidermis = Protection Middle layers = Assists in dehiscence Tapetum = Nourishes pollen grains Endothecium = Provides structural support</p> Signup and view all the answers

    What is the shape of a typical microsporangium in transverse section?

    <p>Near circular</p> Signup and view all the answers

    The outer three wall layers of the anther do not participate in the release of pollen.

    <p>False</p> Signup and view all the answers

    What type of tissue occupies the center of each microsporangium when the anther is young?

    <p>Sporogenous tissue.</p> Signup and view all the answers

    What is the advantage of making hybrid seeds into apomicts?

    <p>Prevents the segregation of traits in offspring</p> Signup and view all the answers

    Pollen grains contain either two or three cells at the time of shedding.

    <p>True</p> Signup and view all the answers

    What are the three parts of the pistil?

    <p>stigma, style, ovary</p> Signup and view all the answers

    What happens when incompatible pollen lands on the stigma?

    <p>The pistil prevents pollen germination or tube growth.</p> Signup and view all the answers

    Pollen grains develop inside the __________.

    <p>microsporangia</p> Signup and view all the answers

    The pistil has the ability to recognize both compatible and incompatible pollen types.

    <p>True</p> Signup and view all the answers

    Match the following parts of the flower with their functions:

    <p>Stigma = Receives pollen during pollination Anther = Produces pollen grains Ovary = Contains ovules Sepals = Protects the flower bud</p> Signup and view all the answers

    What is formed as a result of compatible pollen transfer?

    <p>A pollen tube that leads to fertilization.</p> Signup and view all the answers

    Pollen recognition and response involve a continuous dialogue mediated by __________.

    <p>chemical components</p> Signup and view all the answers

    What agent can be a pollinating factor?

    <p>Either wind or water</p> Signup and view all the answers

    Match the following pollen interactions with their outcomes:

    <p>Compatible Pollen = Accepts and promotes fertilization Incompatible Pollen = Rejects and prevents germination Pollen Tube = Grows through stigma and style to reach ovary Pistil = Recognizes and responds to pollen type</p> Signup and view all the answers

    Microsporogenesis occurs in the pistil of flowers.

    <p>False</p> Signup and view all the answers

    What type of tissue differentiates to form the embryo sac?

    <p>megaspore mother cell</p> Signup and view all the answers

    Which of the following best describes the relationship between pollen and the pistil?

    <p>There is a continuous dialogue mediated by chemical components.</p> Signup and view all the answers

    Pollen tubes do not require growth through the style to reach the ovary.

    <p>False</p> Signup and view all the answers

    What prevents the germination of incompatible pollen on the stigma?

    <p>The pistil's recognition mechanism</p> Signup and view all the answers

    Which event occurs first during pollen-pistil interaction?

    <p>Pollen grain germinates on the stigma</p> Signup and view all the answers

    The developing embryo always forms before the endosperm during seed development.

    <p>False</p> Signup and view all the answers

    What is the result of double fertilization in angiosperms?

    <p>A diploid zygote and a triploid primary endosperm nucleus</p> Signup and view all the answers

    Apomixis leads to the formation of seeds without __________.

    <p>fertilisation</p> Signup and view all the answers

    Match the following stages of dicotyledonous embryo development with their descriptions:

    <p>Proembryo = Initial stage of embryo development Globular = Round shape with developing cotyledons Heart-shaped = Distinct structure resembling a heart Mature embryo = Fully developed with two cotyledons and stem</p> Signup and view all the answers

    Which of the following statements is true about polyembryony?

    <p>It can occur in some angiosperms, producing more than one embryo in a seed</p> Signup and view all the answers

    Cleistogamous flowers can facilitate cross-pollination.

    <p>False</p> Signup and view all the answers

    What is meant by monosporic development of female gametophyte?

    <p>Development of the female gametophyte from a single megaspore</p> Signup and view all the answers

    Which part of the flower represents the male reproductive organ?

    <p>Androecium</p> Signup and view all the answers

    The gynoecium is the part of the flower responsible for producing pollen grains.

    <p>False</p> Signup and view all the answers

    List two flowers commonly used for ornamental purposes.

    <p>Roses, Tulips</p> Signup and view all the answers

    The _______ is the part of the flower that produces ovules.

    <p>ovary</p> Signup and view all the answers

    Match the flower parts with their functions:

    <p>Stamen = Produces pollen Pistil = Contains ovules Petal = Attracts pollinators Sepal = Protects the flower bud</p> Signup and view all the answers

    What is the primary function of flowers in angiosperms?

    <p>Sexual reproduction</p> Signup and view all the answers

    Hormonal changes signify the beginning of floral differentiation.

    <p>True</p> Signup and view all the answers

    What does floriculture refer to?

    <p>The cultivation of flowers and ornamental plants.</p> Signup and view all the answers

    What is the term for the process of seed formation without fertilisation?

    <p>Apomixis</p> Signup and view all the answers

    What term describes fruits that develop from the ovary only?

    <p>True fruits</p> Signup and view all the answers

    Polyembryony refers to the occurrence of more than one embryo in a seed.

    <p>True</p> Signup and view all the answers

    Seeds can remain viable for only a few weeks after dispersal.

    <p>False</p> Signup and view all the answers

    Name a plant species known for producing a large number of seeds.

    <p>Orchid</p> Signup and view all the answers

    Fruits of some parasitic species such as Orobanche and ______ contain a very large number of seeds.

    <p>Striga</p> Signup and view all the answers

    What is the term for seed development without fertilization?

    <p>Parthenocarpy</p> Signup and view all the answers

    The oldest viable seed was that of __________, which germinated after 10,000 years of dormancy.

    <p>Lupinus arcticus</p> Signup and view all the answers

    Match the following plants with their associated fruit type:

    <p>Apple = False fruit Banana = Parthenocarpic fruit Strawberry = False fruit Coconut = True fruit</p> Signup and view all the answers

    What common characteristic do hybrid seeds have?

    <p>They require yearly production</p> Signup and view all the answers

    Which of the following is a benefit of seeds for angiosperms?

    <p>Seeds enhance genetic variation</p> Signup and view all the answers

    Every Ficus tree produces a consistent number of seeds every year.

    <p>False</p> Signup and view all the answers

    What kind of genes do apomictic embryos represent?

    <p>Clones</p> Signup and view all the answers

    False fruits only develop from the ovary of the flower.

    <p>False</p> Signup and view all the answers

    Seeds develop better adaptive strategies for __________ to colonize new habitats.

    <p>dispersal</p> Signup and view all the answers

    What is the primary function of the tapetum in an anther?

    <p>Nourishes the developing pollen grains</p> Signup and view all the answers

    The microsporangium is generally surrounded by three wall layers.

    <p>False</p> Signup and view all the answers

    A typical angiosperm anther is described as being __________ with two theca.

    <p>dithecous</p> Signup and view all the answers

    During microsporogenesis, what type of divisions do the cells of the sporogenous tissue undergo?

    <p>Meiotic divisions</p> Signup and view all the answers

    The anther is a six-sided structure containing six microsporangia.

    <p>False</p> Signup and view all the answers

    What is the ploidy level of the cells in a microspore tetrad?

    <p>haploid</p> Signup and view all the answers

    What is the process called that leads to the formation of microspores from a pollen mother cell?

    <p>Microsporogenesis</p> Signup and view all the answers

    The microspores dissociate and develop into pollen grains while the anthers are still maturing.

    <p>False</p> Signup and view all the answers

    What material makes up the hard outer layer of the pollen grain?

    <p>Sporopollenin</p> Signup and view all the answers

    The inner wall of the pollen grain is called the _____

    <p>intine</p> Signup and view all the answers

    Match the following parts of the pollen grain with their descriptions:

    <p>Exine = Hard outer layer made of sporopollenin Intine = Inner wall of the pollen grain Germ pores = Apertures in the exine where sporopollenin is absent Microsporangium = Structure where microspores are formed</p> Signup and view all the answers

    Which of the following statements about pollen grains is true?

    <p>Pollen grains are generally spherical and exhibit a variety of shapes.</p> Signup and view all the answers

    Sporopollenin is known to be easily degraded by environmental factors.

    <p>False</p> Signup and view all the answers

    What happens to pollen grains when the anther dehisces?

    <p>They are released.</p> Signup and view all the answers

    What type of pollination allows for the transfer of pollen grains between flowers of the same plant?

    <p>Geitonogamy</p> Signup and view all the answers

    Cleistogamous flowers require pollinators for seed set.

    <p>False</p> Signup and view all the answers

    Which type of pollination involves the transfer of pollen grains from one plant to another, leading to genetic diversity?

    <p>Xenogamy</p> Signup and view all the answers

    Cleistogamous flowers ensure seed-set even in the absence of __________.

    <p>pollinators</p> Signup and view all the answers

    Match the following types of pollination with their characteristics:

    <p>Cleistogamy = Self-pollination without opening Geitonogamy = Pollen from another flower of the same plant Xenogamy = Pollen from a different plant Autogamy = Pollen from the same flower</p> Signup and view all the answers

    What type of agents do the majority of plants use for pollination?

    <p>Biotic agents</p> Signup and view all the answers

    Geitonogamy results in genetically distinct offspring.

    <p>False</p> Signup and view all the answers

    Name one abiotic agent utilized in pollination.

    <p>Wind</p> Signup and view all the answers

    What is the primary function of the coleorrhiza?

    <p>To protect the radical and root cap</p> Signup and view all the answers

    Albuminous seeds contain no residual endosperm.

    <p>False</p> Signup and view all the answers

    What part of the seed facilitates the entry of oxygen and water during germination?

    <p>Micropyle</p> Signup and view all the answers

    The wall of the ovary develops into the __________ after fertilization.

    <p>pericarp</p> Signup and view all the answers

    Match the type of seed with its characteristic:

    <p>Non-albuminous seeds = Completely consume endosperm during embryo development Albuminous seeds = Retain part of the endosperm Ex-albuminous seeds = Does not refer to actual seed type Perisperm = Remnant of the nucellus</p> Signup and view all the answers

    Which of these fruits is classified as fleshy?

    <p>Mango</p> Signup and view all the answers

    Dormancy is a state of activity in seeds.

    <p>False</p> Signup and view all the answers

    What is the term for the seed coat that protects seeds as they develop?

    <p>Integuments</p> Signup and view all the answers

    Which of the following mechanisms prevents self-pollination in flowering plants?

    <p>Different placement of anthers and stigma</p> Signup and view all the answers

    Pollen/nectar robbers do contribute to the pollination process.

    <p>False</p> Signup and view all the answers

    What is the term used to describe flowers that have both male and female reproductive structures?

    <p>Hermaphrodite</p> Signup and view all the answers

    In some flowering plant species, the genetic mechanism that prevents self-pollen from fertilizing the ovules is called __________.

    <p>self-incompatibility</p> Signup and view all the answers

    Match the following types of flower arrangements with their descriptions:

    <p>Monoecious = Plant possesses both male and female flowers Dioecious = Individual plants are either male or female Hermaphrodite = Contains both male and female reproductive structures Unisexual = Flowers have only one type of reproductive organ</p> Signup and view all the answers

    Which of the following flowers would be most likely to attract specific pollinators?

    <p>Flowers with a strong scent and bright colors</p> Signup and view all the answers

    Geitonogamy refers to pollination that occurs within the same flower.

    <p>False</p> Signup and view all the answers

    What does a flower need to have contact with in order to achieve successful pollination?

    <p>Anthers and stigma</p> Signup and view all the answers

    What type of flowers are primarily targeted by insect pollinators?

    <p>Large, colourful, and fragrant</p> Signup and view all the answers

    Flowers that are pollinated by flies and beetles typically secrete pleasant fragrances.

    <p>False</p> Signup and view all the answers

    What are the usual floral rewards provided to attract animal visitors?

    <p>Nectar and pollen grains</p> Signup and view all the answers

    The body of the animal gets a coating of ______, which helps in pollination.

    <p>pollen grains</p> Signup and view all the answers

    Match the following floral features with their purposes:

    <p>Colour = Attracts pollinators Fragrance = Enhances floral appeal Nectar = Provides rewards Inflorescence = Increases visibility</p> Signup and view all the answers

    Which element of the flower facilitates the contact needed for pollination?

    <p>Stigma</p> Signup and view all the answers

    The tallest flower, Amorphophallus, provides safe places for moths to lay their eggs.

    <p>True</p> Signup and view all the answers

    What is one example of a plant that forms a mutual relationship with a moth for pollination?

    <p>Yucca</p> Signup and view all the answers

    What is apomixis in flowering plants?

    <p>A form of asexual reproduction mimicking sexual reproduction</p> Signup and view all the answers

    Polyembryony refers to the occurrence of multiple seeds in a single fruit.

    <p>False</p> Signup and view all the answers

    Name one flowering plant that produces a large number of seeds.

    <p>Orchid</p> Signup and view all the answers

    The process of seed formation without fertilization is called __________.

    <p>apomixis</p> Signup and view all the answers

    What happens in polyembryony?

    <p>Multiple embryos develop within a single seed</p> Signup and view all the answers

    What genetic nature do apomictic embryos have?

    <p>They are clones.</p> Signup and view all the answers

    Hybrid seeds can be regenerated from saved seeds of hybrid plants.

    <p>False</p> Signup and view all the answers

    What is the first cell type formed during syngamy in double fertilization?

    <p>Diploid zygote</p> Signup and view all the answers

    Endosperm development occurs after the embryo development.

    <p>False</p> Signup and view all the answers

    What is the primary outcome of meiosis in the megaspore mother cell (MMC)?

    <p>Production of four megaspores</p> Signup and view all the answers

    The functional megaspore is the only megaspore that develops into the female gametophyte.

    <p>True</p> Signup and view all the answers

    What is double fertilization?

    <p>The process where one male gamete fertilizes the egg cell and the other fuses with two polar nuclei.</p> Signup and view all the answers

    The primary endosperm cell becomes the _____ during seed development.

    <p>endosperm</p> Signup and view all the answers

    What term describes the method of embryo sac formation from a single megaspore?

    <p>Monosporic development</p> Signup and view all the answers

    The embryo sac undergoes mitotic divisions that are strictly _____ nuclear.

    <p>free</p> Signup and view all the answers

    During the pollination process, what happens after the stigma becomes receptive?

    <p>Pollen is dusted on the stigma</p> Signup and view all the answers

    Match the stages of the embryo sac development with the number of nuclei:

    <p>2-nucleate stage = 2 nuclei 4-nucleate stage = 4 nuclei 8-nucleate stage = 8 nuclei Mature embryo sac = 7 nuclei</p> Signup and view all the answers

    The central cell becomes the primary endosperm cell after triple fusion.

    <p>True</p> Signup and view all the answers

    Which of the following cells constitutes the egg apparatus in the embryo sac?

    <p>Two synergids and one egg cell</p> Signup and view all the answers

    The functional megaspore is produced from the MMC without undergoing any cell divisions.

    <p>False</p> Signup and view all the answers

    What is the significance of the endosperm in seed development?

    <p>It provides nourishment to the developing embryo.</p> Signup and view all the answers

    How many nuclei are typically found in the mature embryo sac?

    <p>Seven</p> Signup and view all the answers

    What major contribution did Panchanan Maheshwari make to education?

    <p>Published the first textbooks of Biology for Higher Secondary Schools.</p> Signup and view all the answers

    Panchanan Maheshwari focused primarily on the study of animal physiology.

    <p>False</p> Signup and view all the answers

    Panchanan Maheshwari was instrumental in introducing the use of embryological characters in ______.

    <p>taxonomy</p> Signup and view all the answers

    Which of the following statements correctly describes Panchanan Maheshwari's work on fertilization?

    <p>He conducted research on test tube fertilization and intra-ovarian pollination.</p> Signup and view all the answers

    Which of the following external agents can assist in pollination?

    <p>All of the above</p> Signup and view all the answers

    Autogamy is a type of pollination that occurs between different flowers.

    <p>False</p> Signup and view all the answers

    What is the typical cellular structure found at the micropylar tip of synergids that aids in guiding pollen tubes?

    <p>filiform apparatus</p> Signup and view all the answers

    The embryo sac contains ____ nuclei in total.

    <p>8</p> Signup and view all the answers

    Which structure in flowering plants is responsible for housing the female gametes?

    <p>Embryo sac</p> Signup and view all the answers

    In cleistogamous flowers, the anthers and stigma are typically far apart.

    <p>False</p> Signup and view all the answers

    How many cells are present in a typical mature angiosperm embryo sac?

    <p>7</p> Signup and view all the answers

    What is the function of sporopollenin in pollen grains?

    <p>To provide structural integrity</p> Signup and view all the answers

    Pollen grains are typically oval in shape.

    <p>False</p> Signup and view all the answers

    What are the two layers of a pollen grain wall called?

    <p>Exine and Intine</p> Signup and view all the answers

    The process of forming microspores from a pollen mother cell is called __________.

    <p>microsporogenesis</p> Signup and view all the answers

    Match the following terms related to pollen grains with their definitions:

    <p>Exine = Hard outer layer of pollen grains Intine = Inner wall of the pollen grain Germ pores = Apertures in the exine Sporopollenin = Resistant organic material in the exine</p> Signup and view all the answers

    What happens to the microspores as the anthers mature?

    <p>They develop into pollen grains</p> Signup and view all the answers

    The presence of sporopollenin prevents pollen grains from decaying and allows them to be preserved as fossils.

    <p>True</p> Signup and view all the answers

    What is the significance of germ pores in pollen grains?

    <p>They allow for the emergence of the pollen tube.</p> Signup and view all the answers

    What is the name of the stage in endosperm development characterized by free nuclei?

    <p>Free-nuclear endosperm</p> Signup and view all the answers

    Coconut water is composed of cellular endosperm.

    <p>False</p> Signup and view all the answers

    What structure develops at the micropylar end of the embryo sac?

    <p>embryo</p> Signup and view all the answers

    The cylindrical portion of the embryonal axis below the level of cotyledons is called the _____ .

    <p>hypocotyl</p> Signup and view all the answers

    Which structure is termed the root tip in a dicotyledonous embryo?

    <p>Radicle</p> Signup and view all the answers

    Embryos of monocotyledons possess two cotyledons.

    <p>False</p> Signup and view all the answers

    The portion of the embryonal axis above the level of cotyledons is called the _____ .

    <p>epicotyl</p> Signup and view all the answers

    What term describes the type of seed production that occurs without fertilization?

    <p>Apomixis</p> Signup and view all the answers

    Polyembryony refers to the occurrence of only one embryo within a seed.

    <p>False</p> Signup and view all the answers

    Name one flowering plant known for producing a large number of seeds.

    <p>Ficus</p> Signup and view all the answers

    In some species, _______________ cells surrounding the embryo sac can develop into embryos.

    <p>nucellar</p> Signup and view all the answers

    Which part of a flowering plant contains multiple ovules?

    <p>Ovary</p> Signup and view all the answers

    Every flowering plant produces seeds produced by fertilization.

    <p>False</p> Signup and view all the answers

    Which of the following describes a unique adaptation of flower structures in water-pollinated species?

    <p>Pollen grains are released inside the water.</p> Signup and view all the answers

    What can happen if hybrid seeds are collected and sown?

    <p>They will segregate and not maintain hybrid characteristics.</p> Signup and view all the answers

    Animal-pollinated plants generally require brighter colored flowers to attract various pollinators.

    <p>True</p> Signup and view all the answers

    Name two common pollinating agents among animals.

    <p>Bees and butterflies</p> Signup and view all the answers

    Pollen grains in some water-pollinated species are protected by a _____ covering.

    <p>mucilaginous</p> Signup and view all the answers

    Match the following pollinating agents with their characteristics:

    <p>Bees = Dominant biotic pollinators for many flowering plants Hummingbirds = Known for pollinating red and tubular flowers Bats = Pollinators of night-blooming plants Butterflies = Prefer flowers with flat landing platforms</p> Signup and view all the answers

    Pollen grains in animal-pollinated flowers are typically long and ribbon-like.

    <p>False</p> Signup and view all the answers

    Both wind and water-pollinated flowers do not produce ______.

    <p>nectar</p> Signup and view all the answers

    What is the primary function of the vegetative cell in a mature pollen grain?

    <p>To provide nutrients</p> Signup and view all the answers

    In most angiosperms, pollen grains are shed at the 3-celled stage.

    <p>False</p> Signup and view all the answers

    What can cause severe allergies and bronchial afflictions in some individuals?

    <p>Pollen grains</p> Signup and view all the answers

    Pollen grains lose viability within _____ minutes after being released in some cereals like rice and wheat.

    <p>30</p> Signup and view all the answers

    Match the following pollen grain stages with their characteristics:

    <p>2-celled stage = Pollen grains are shed in this stage 3-celled stage = Generative cell divides to form two male gametes Viability = Varies based on temperature and humidity Liquid nitrogen storage = Allows pollen to be preserved for years</p> Signup and view all the answers

    What is a common use of pollen products in western countries?

    <p>As food supplements</p> Signup and view all the answers

    What is a significant danger associated with Parthenium or carrot grass?

    <p>It causes pollen allergy.</p> Signup and view all the answers

    Pollen grains can remain viable for many years when stored in liquid nitrogen.

    <p>True</p> Signup and view all the answers

    What happens if the pollen transferred to the pistil is of the incompatible type?

    <p>The pistil prevents pollen germination.</p> Signup and view all the answers

    The pistil's ability to recognize pollen is solely based on genetic compatibility.

    <p>False</p> Signup and view all the answers

    Which part of the seed serves as the storage for food reserves?

    <p>Cotyledon</p> Signup and view all the answers

    What is the role of the pollen tube in the fertilization process?

    <p>To transport male gametes to the ovary.</p> Signup and view all the answers

    Albuminous seeds retain part of the endosperm during embryo development.

    <p>True</p> Signup and view all the answers

    The dialogue between pollen grain and pistil is mediated by ______ components.

    <p>chemical</p> Signup and view all the answers

    What is the role of the micropyle in a seed?

    <p>The micropyle allows the entry of oxygen and water during seed germination.</p> Signup and view all the answers

    What promotes post-pollination events leading to fertilization?

    <p>Compatible pollen</p> Signup and view all the answers

    In most angiosperms, seeds are formed inside __________.

    <p>fruits</p> Signup and view all the answers

    Match the components with their functions in the pollination process:

    <p>Pollen grain = Contains male gametes Pistil = Recognizes and interacts with pollen Pollen tube = Delivers gametes to the ovule Stigma = Site for pollen attachment</p> Signup and view all the answers

    The interaction between pollen and the pistil occurs entirely after fertilization.

    <p>False</p> Signup and view all the answers

    Match the following types of seeds with their characteristics:

    <p>Non-albuminous = No residual endosperm Albuminous = Retains part of the endosperm Perisperm = Remnants of nucellus Cotyledons = Store food reserves</p> Signup and view all the answers

    What is dormancy in the context of seeds?

    <p>A period of inactivity</p> Signup and view all the answers

    What is the outcome if the pistil accepts compatible pollen?

    <p>Fertilization occurs.</p> Signup and view all the answers

    Both the ovules and the ovary develop simultaneously into seeds and fruits, respectively.

    <p>True</p> Signup and view all the answers

    Name one example of a fleshy fruit.

    <p>Guava</p> Signup and view all the answers

    What factor primarily attracts animals to flowers for pollination?

    <p>Color and fragrance</p> Signup and view all the answers

    Flowers pollinated by flies and beetles secrete pleasant fragrances to attract these animals.

    <p>False</p> Signup and view all the answers

    What rewards do flowers typically provide to attract animal visitors?

    <p>Nectar and pollen grains</p> Signup and view all the answers

    The body of the animal gets coated with _____ grains during pollination.

    <p>pollen</p> Signup and view all the answers

    Match the following types of pollinators with their related characteristics:

    <p>Bees = Attracted to bright colors and sweet nectar Flies = Drawn by foul odors Beetles = Often attracted to large flowers Moths = Pollinate at night and attracted to fragrance</p> Signup and view all the answers

    Which of the following describes a unique relationship between certain flowers and pollinators?

    <p>Flowers provide safe places for pollinators to lay eggs</p> Signup and view all the answers

    Animal-pollinated flowers can simply rely on their size to attract visitors.

    <p>False</p> Signup and view all the answers

    Name one example of a flower that is tall and attracts specific pollinators due to its height.

    <p>Amorphophallus</p> Signup and view all the answers

    What is the initial condition in which pollen grains are shed in some plants?

    <p>Two-celled condition</p> Signup and view all the answers

    The process of bagging is performed to allow for cross-pollination.

    <p>False</p> Signup and view all the answers

    What is the term used for the process of removing anthers from the flower bud to prevent self-pollination?

    <p>emasculation</p> Signup and view all the answers

    Pollen tubes carry the two male gametes from the _____ condition.

    <p>three-celled</p> Signup and view all the answers

    Match the following pollination techniques with their purposes:

    <p>Emasculation = Removal of anthers to prevent self-pollination Bagging = Protection of stigma from unwanted pollen Pollen-pistil interaction = Guides the entry of pollen tube Artificial hybridization = Combining desirable traits from different species</p> Signup and view all the answers

    What facilitates the entry of the pollen tube into the ovule?

    <p>Filiform apparatus</p> Signup and view all the answers

    What is the duration of time you should observe the slide under a microscope after dusting with pollen?

    <p>15-30 minutes</p> Signup and view all the answers

    Pollen-pistil interaction is a dynamic and static process.

    <p>False</p> Signup and view all the answers

    Apomixis is the process that allows plants to produce seeds without fertilization.

    <p>True</p> Signup and view all the answers

    What are the two types of cell division that occur during microsporogenesis and megasporogenesis?

    <p>Meiosis and mitosis</p> Signup and view all the answers

    The developing embryo passes through several stages including the __________ and heart-shaped stages before maturation.

    <p>globular</p> Signup and view all the answers

    Which structure develops into the endosperm during fertilization?

    <p>Polar nuclei</p> Signup and view all the answers

    Cleistogamous flowers are capable of cross-pollination.

    <p>False</p> Signup and view all the answers

    What feature helps protect pollen grains from wetting in many water-pollinated species?

    <p>A mucilaginous covering</p> Signup and view all the answers

    All water-pollinated plants have their female flowers above water.

    <p>False</p> Signup and view all the answers

    Name one group of animals that are dominant biotic pollinators.

    <p>Bees</p> Signup and view all the answers

    Flowers of animal-pollinated plants are specifically adapted for a particular species of _____.

    <p>animal</p> Signup and view all the answers

    Match the following pollination methods with their characteristics:

    <p>Wind Pollination = Pollen carried by air currents Water Pollination = Pollen carried by water currents Animal Pollination = Pollen transferred by animals Self-Pollination = Pollen transferred within the same flower</p> Signup and view all the answers

    Why are most wind and water pollinated flowers not very colorful?

    <p>They rely mainly on water and air currents for pollination.</p> Signup and view all the answers

    In addition to insects, larger animals like primates can also act as pollinators.

    <p>True</p> Signup and view all the answers

    Pollen grains in water-pollinated plants are often described as _____ and ribbon-like.

    <p>long</p> Signup and view all the answers

    What is the primary process by which pollen mother cells form microspores?

    <p>Microsporogenesis</p> Signup and view all the answers

    Pollen grains are typically measured in millimeters.

    <p>False</p> Signup and view all the answers

    Match the following components of the pollen grain with their characteristics:

    <p>Exine = Hard outer layer made of sporopollenin Intine = Inner wall of the pollen grain Germ pores = Apertures in the exine Microspore tetrad = Cluster of four microspores</p> Signup and view all the answers

    Which feature of sporopollenin contributes to the preservation of pollen grains as fossils?

    <p>Its high resistance to degradation</p> Signup and view all the answers

    Microspores develop into pollen grains while they are still in the microsporangium.

    <p>False</p> Signup and view all the answers

    What is the role of germ pores in pollen grains?

    <p>Allow for pollen tube germination</p> Signup and view all the answers

    What is the typical ploidy of the cells in a microspore tetrad?

    <p>Tetraploid</p> Signup and view all the answers

    The tapetum wall layer in the anther is responsible for the protection and dehiscence of the anther.

    <p>False</p> Signup and view all the answers

    What structure in the anther develops into pollen sacs?

    <p>Microsporangia</p> Signup and view all the answers

    A typical angiosperm anther is described as being __________ in structure.

    <p>bilobed</p> Signup and view all the answers

    Match the components of a microsporangium with their functions:

    <p>Epidermis = Protects the anther Endothecium = Aids in anther dehiscence Middle layers = Provides additional protection Tapetum = Nourishes developing pollen grains</p> Signup and view all the answers

    What is the function of sporogenous tissue in the anther?

    <p>Forming microspore tetrads</p> Signup and view all the answers

    In a transverse section, the microsporangium has a circular outline.

    <p>True</p> Signup and view all the answers

    How many microsporangia are typically located at the corners of an anther?

    <p>Four</p> Signup and view all the answers

    What is the primary reason animals are attracted to insect-pollinated flowers?

    <p>They are hungry for nectar and pollen</p> Signup and view all the answers

    Flowers that are pollinated by flies and beetles emit sweet fragrances to attract these insects.

    <p>False</p> Signup and view all the answers

    What are the two usual floral rewards provided to animals by insect-pollinated flowers?

    <p>Nectar and pollen grains</p> Signup and view all the answers

    When an animal comes in contact with the anthers and stigma, it facilitates __________.

    <p>pollination</p> Signup and view all the answers

    Match the flowers with their attraction methods:

    <p>Insect-pollinated flowers = Attract with colour and fragrance Flowers pollinated by flies = Secrete foul odours Amorphophallus = Provides safe places to lay eggs Yucca plant = Mutual dependency with moth for reproduction</p> Signup and view all the answers

    What type of floral mechanism is utilized by flowers that cluster small flowers into an inflorescence?

    <p>Conspicuous attraction</p> Signup and view all the answers

    Pollen grains are generally sticky in all types of flowers.

    <p>False</p> Signup and view all the answers

    Name one species that has a mutual dependency between a moth and a plant.

    <p>Yucca</p> Signup and view all the answers

    What happens if the pollen that lands on the stigma is incompatible?

    <p>The pistil rejects the pollen and prevents germination.</p> Signup and view all the answers

    The pollen tube grows through the style even if the pollen is of the wrong type.

    <p>False</p> Signup and view all the answers

    What mediates the dialogue between pollen grains and the pistil?

    <p>Chemical components of the pollen and pistil.</p> Signup and view all the answers

    If the pistil recognizes the pollen as compatible, it promotes ________ events that lead to fertilization.

    <p>post-pollination</p> Signup and view all the answers

    Match the processes involved in pollen-pistil interaction with their descriptions:

    <p>Germination of pollen = Pollen tube grows through the stigma Pollen tube growth = Pollen tube reaches the ovary Chemical signaling = Pollen-pistil dialogue Rejection of incompatible pollen = Prevents pollen germination</p> Signup and view all the answers

    Which statement accurately describes the role of the pistil in pollination?

    <p>The pistil can recognize and respond to both compatible and incompatible pollen.</p> Signup and view all the answers

    Pistils are incapable of recognizing pollen grains from the same plant species.

    <p>False</p> Signup and view all the answers

    What is the first step that occurs once compatible pollen lands on the stigma?

    <p>The pollen grain germinates.</p> Signup and view all the answers

    What event occurs during double fertilization in angiosperms?

    <p>Fusion of two male gametes with one egg cell and two polar nuclei.</p> Signup and view all the answers

    Monosporic development of the female gametophyte results in the formation of one functional megaspore.

    <p>True</p> Signup and view all the answers

    What is the primary product of triple fusion in angiosperms?

    <p>Triploid primary endosperm nucleus</p> Signup and view all the answers

    Apomixis allows for the formation of seeds without __________.

    <p>fertilization</p> Signup and view all the answers

    Match the parts of the angiosperm flower with their roles in gametophyte development:

    <p>Anther = Produces male gametophytes Ovule = Develops into the female gametophyte Stigma = Receives pollen Sporangium = Site of meiosis for pollen and ovule</p> Signup and view all the answers

    Which of the following stages is NOT a part of dicotyledonous embryo development?

    <p>Mature single-cotyledon stage</p> Signup and view all the answers

    Self-incompatibility prevents successful fertilization even in compatible mating types.

    <p>True</p> Signup and view all the answers

    Name the phenomenon where more than one embryo develops in a seed.

    <p>Polyembryony</p> Signup and view all the answers

    Study Notes

    Panchanan Maheshwari

    • Born in 1904 in Jaipur, Rajasthan, India
    • Became a distinguished botanist
    • Completed his D.Sc. in Allahabad
    • Inspired by Dr. W. Dudgeon to study botany
    • Worked on embryology and taxonomy
    • Established the Department of Botany at the University of Delhi
    • Focused on embryology and tissue culture
    • Research on artificial culture of immature embryos
    • Work on test-tube fertilization and intra-ovarian pollination recognised worldwide
    • Fellow of the Royal Society of London (FRS) and the Indian National Science Academy among other institutions
    • Contributed to school education by writing the first biology textbooks for higher secondary schools published by NCERT in 1964
    • His work greatly popularized the use of embryological characters in taxonomy.
    • Developed interest in the morphology of plants.
    • Encouraged his student to surpass him.
    • Popularized the use of embryological characters as a tool in taxonomy.
    • Inspired his students to take a lead in botany and develop a keen interest in morphology.
    • Recognized for his significant contribution to school education
    • His teacher's words inspired him to contribute to botany
    • His teacher expressed a desire for satisfaction in seeing his student progress beyond him

    Sexual Reproduction in Flowering Plants

    • Flowers aid sexual reproduction in plants
    • Flowers display diversity in inflorescences, flowers, and floral parts resulting in attractive aesthetic qualities
    • Adaptations in flowers ensure fruit and seed formation
    • Flowers have aesthetic, ornamental, social, religious, and cultural value
    • Flowers act as symbols for conveying important human feelings
    • Show diversity in structures of inflorescences, flowers and floral parts
    • The rich colours and diversity of flowers are essential for reproduction

    Flower Structure and Parts

    • Flowers have a variety of parts, such as stigma, style, anther, petal, filament, ovule, etc.
    • Flowers are essential for sexual reproduction in flowering plants
    • Different parts of the flower exhibit variation in shape and size
    • Detailed diagrams are essential for understanding the range of shape and attachment of flowers in different species

    Stamen, Microsporangium and Pollen Grain

    • Stamens consist of filament and anther, attached to the thalamus or petal
    • Anthers are bilobed and dithecous
    • The anther has four microsporangia inside
    • The wall of microsporangium contains four layers: epidermis, endothecium, middle layers, tapetum
    • Sporogenous tissue in the center of microsporangium
    • Microsporogenesis involves meiosis to form microspore tetrads
    • The microspore will become the pollen grains
    • Microspores dissociate, and mature into pollen grains

    Pollen Grain

    • Pollen grains are spherical
    • Vary in size (25-50 micrometers)
    • Covered by a hard outer layer (exine) made of sporopollenin
    • Contain germ pores where sporopollenin is absent
    • Contain intine, the inner layer, composed of cellulose and pectin
    • Pollen grains have a vegetative cell and a generative cell
    • Pollen grains are well-preserved as fossils because of sporopollenin presence, important for fossil records.

    Pollen Grain and Pollination

    • Pollen grains must land on stigma.
    • Viability varies depending on prevailing temperature and humidity
    • Pollen can be stored in liquid nitrogen for long periods
    • Methods like emasculation and bagging are used in plant breeding to prevent unwanted self-pollination.
    • Various strategies to increase chances of pollen landing on the stigma.
    • Pollination can be abiotic (wind, water) or biotic (animals)
    • Pollination by wind is common, pollen grains are light and non-sticky.
    • Pollination by water is rare; pollen grains are adapted for water movement.
    • Pollination by animals is common; colours, fragrances, and nectar.
    • Pollination can be self-pollination (autogamy/geitonogamy) or cross-pollination (xenogamy)

    The Pistil, Megasporangium (Ovule) and Embryo Sac

    • The gynoecium is the female reproductive part
    • Consists of one or more pistils (syncarpous/apocarpous)
    • Each pistil has three parts: stigma, style, and ovary.
    • Ovary contains ovules (megasporangia)
    • Inside the ovule is the embryo sac (female gametophyte)
    • Megasporogenesis: Formation of the megaspore mother cell (MMC) in the micropylar region resulting in megaspores.
    • Female gametophyte develops from one of the megaspores.
    • Ovules have protective layers called integuments with a small opening, the micropyle, for pollen tube entry.

    Double Fertilisation

    • Two male gametes fuse with two nuclei, forming a zygote and primary endosperm nucleus
    • This is a unique phenomenon for angiosperms
    • Zygote develops into an embryo
    • Primary endosperm nucleus develops into endosperm tissue
    • This ensures that there is sufficient nutritive tissue to nourish embryo.

    Post-Fertilisation Events

    • Endosperm development precedes embryo development
    • Endosperm nourishes the developing embryo
    • Ovule develops into a seed
    • Ovary develops into a fruit
    • Post-fertilisation events are subsequent to fertilization

    Seed

    • Seeds are the final products of sexual reproduction.
    • Consists of seed coat(s), cotyledon(s), and embryo axis.
    • Seeds have reserves for nourishing embryos
    • Non-albuminous or ex-albuminous
    • Seeds offer advantages for survival
    • Some seeds can remain viable for thousands or even tens of thousands of years.

    Apomixis and Polyembryony

    • Apomixis is asexual reproduction that mimics sexual reproduction. Results in seed formation without fertilization
    • Polyembryony involves the occurrence of multiple embryos in a single seed
    • Hybrid varieties can be made into apomicts to maintain the hybrid in subsequent generations.

    Additional Information

    • Panchanan Maheshwari also contributed to the development of understanding embryological aspects and popularized their use in taxonomy.
    • Panchanan Maheshwari's work on test-tube fertilization and intra-ovarian pollination won worldwide acclaim.
    • Panchanan Maheshwari was honored with fellowships from the Royal Society of London (FRS) and the Indian National Science Academy.

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    Description

    This quiz covers key concepts related to plant reproduction, particularly focusing on the roles of synergies, pollination types, and fertilization processes in angiosperms. Test your understanding of terms like autogamy, syngamy, and the functions of structures in the embryo sac. Perfect for students of botany.

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