Fertilization in flowering plants involves a double fertilization process. The pollen grain contains two sperm cells that travel down the pollen tube. One sperm cell fertilizes the egg cell to form a zygote, while the second sperm cell fertilizes the two polar nuclei to form the endosperm. This double fertilization results in the formation of an embryo from the zygote and endosperm to nourish the developing seed. The ovary then develops into a fruit containing one or more seeds formed from the fertilized ovules.
Wall layers of anther have different functions most importantly they help in providing nutrition to developing pollens and also help in anther dehiscence.
Ginkgo is known as a Living Fossil.Anatomy of Ginkgo clearly shows primary and secondary structures. sex in Ginkgo is determined by sex chromosomes (XY in male and XX in female). Reproductive bodies of Ginkgo are most primitive among living seed plants except some Cycadales. Ginkgos are dioecious, with separate sexes, some trees being female and others being male. Male plants produce small pollen cones with sporophylls, each bearing two microsporangia spirally arranged around a central axis. Female plants do not produce cones. Two ovules are formed at the end of a stalk, and after pollination, one or both develop into seeds. The fertilization of ginkgo seeds occurs via motile sperm, as in cycads, ferns, mosses and algae.
Wall layers of anther have different functions most importantly they help in providing nutrition to developing pollens and also help in anther dehiscence.
Ginkgo is known as a Living Fossil.Anatomy of Ginkgo clearly shows primary and secondary structures. sex in Ginkgo is determined by sex chromosomes (XY in male and XX in female). Reproductive bodies of Ginkgo are most primitive among living seed plants except some Cycadales. Ginkgos are dioecious, with separate sexes, some trees being female and others being male. Male plants produce small pollen cones with sporophylls, each bearing two microsporangia spirally arranged around a central axis. Female plants do not produce cones. Two ovules are formed at the end of a stalk, and after pollination, one or both develop into seeds. The fertilization of ginkgo seeds occurs via motile sperm, as in cycads, ferns, mosses and algae.
Pollen pistil interaction
Types of Incompatibility in plants
Methods to overcome Incompatibility
Prepared by
Dr. T. Annie Sheron
Assistant Professor of Botany
DEPARTMENT OF BOTANY
KAKATIYA GOVERNMENT COLLEGE, HANAMKONDA
Structure, Development & Function of PeridermFatima Ramay
A group of secondary tissues forming a protective layer which replaces the epidermis of many plant stems, roots, and other parts.
Although periderm may develop in leaves and fruits, its main function is to protects stems and roots.
The periderm consists of three different layers:
Phelloderm
Phellogen (cork cambium)
Phellem (cork)
Its main function is to protect the underlying tissues from:
Desiccation
Freezing
Heat injury
Mechanical destruction
Disease
Loss of epidermis.
Bounding tissue restricting the pathogen & insects.
Allowing gaseous exchange through lenticels.
Xerophytes are plants which grow in xeric environment. They have adapted morphological, physiological and anatomical changes in order to survive in xeric conditions. Various anatomical adaptations in xerophytic plants which helps to absorb as much as water as possible, to store for long time and to reduce the rate of transpiration which enables them to survive in xeric condition are included in the presentation.
The ovules is also known as megasporongia which are borne on a cushion-like tissue called placenta in the ovary. One or more than one ovules are present inside the ovary.
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of;India : 75%Amazon : 43%Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Pollen pistil interaction
Types of Incompatibility in plants
Methods to overcome Incompatibility
Prepared by
Dr. T. Annie Sheron
Assistant Professor of Botany
DEPARTMENT OF BOTANY
KAKATIYA GOVERNMENT COLLEGE, HANAMKONDA
Structure, Development & Function of PeridermFatima Ramay
A group of secondary tissues forming a protective layer which replaces the epidermis of many plant stems, roots, and other parts.
Although periderm may develop in leaves and fruits, its main function is to protects stems and roots.
The periderm consists of three different layers:
Phelloderm
Phellogen (cork cambium)
Phellem (cork)
Its main function is to protect the underlying tissues from:
Desiccation
Freezing
Heat injury
Mechanical destruction
Disease
Loss of epidermis.
Bounding tissue restricting the pathogen & insects.
Allowing gaseous exchange through lenticels.
Xerophytes are plants which grow in xeric environment. They have adapted morphological, physiological and anatomical changes in order to survive in xeric conditions. Various anatomical adaptations in xerophytic plants which helps to absorb as much as water as possible, to store for long time and to reduce the rate of transpiration which enables them to survive in xeric condition are included in the presentation.
The ovules is also known as megasporongia which are borne on a cushion-like tissue called placenta in the ovary. One or more than one ovules are present inside the ovary.
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of;India : 75%Amazon : 43%Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Class 12||Chapter 2|| Sexual Reproduction in flowering plantsPrathamBiology
This chapter includes flowers, their detailed structure and developmental processess which took place durin sexual reproduction. Helpful for Board and NEET students.
Fell free for any query or suggestion
Mail us on: biologypratham@gmail.com
Website : www.prathambiology.in
Reproduction ensures continuity of species generation after generations as the older individuals undergo senescence and die. Flowering plants shows sexual mode of reproduction and bears complex reproductive units as male and female reproductive units along with accessary structures.
Flower is a modified stem which functions as a reproductive organ and produces ova and/or pollen. A typical angiospermic flower consists of four whorls of floral appendages attached on the receptacle: calyx, corolla, androecium (male reproductive organ consisting of stamens) and gynoecium (composed of ovary, style and stigma) .
Table of Contents:
a. Structure
b. Reproductive Structure
c. Androecium
d. Microsporogenesis
e. Gynoecium
f. Megasporogenesis
g. Pollination
h. Fertilization
i. Functions
Explore sexual reproduction in flowering plants notes to learn about the reproductive structure of the flower and the process of pollination.
description of different types of reproductive organs, developmental stages and process of reproduction in Cycas. Various internet sources have been used.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
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The Roman Empire A Historical Colossus.pdfkaushalkr1407
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Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
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3. INTRODUCTION
Fertilization is the fusion of the nuclei of male and female gamete to form a zy
Fertilization in flowering plants was discovered by
Ralph B. Strasburger in the year 1884.
In flowering plants-
The pollen grain is the male gamete.
The ovule inside the ovary is the female gamete.
4. THE POLLEN GRAIN
Vary in size from 10-200micron.
Each pollen has two coats-
Exine
This is tough, cutinized outer protective coat. It is often provided with spiny
outgrowths or a rough surface as an adaptation for pollination.
Intine
It is a thin delicate cellulose layer lying internal to the exine. It is the intine
that grows into the pollen tube.
The nucleus of mature pollen grain has already divided into two nuclei at
the time of pollination. The two nuclei are –the tube nucleus and the
generative nucleus.
5. the microsporangium is known as microsporogenesis.
When the anther is young, a layer of homogenous
cells occupies the center of each microsporangium, is
known as sporogenous tissue. It is diploid (2n) inn
nature.
The sporogenous tissue undergo meiotic divisions
to form microspore tetrads (four microspores) which
are haploid (n).
These microspores nature to form pollen grains,
male gametes. Each microsporangium contains
thousand of microspores or pollen grains.
Pollen or microspores are very tiny round
structures. After the formation, microspores or pollen
grain dry up and become powdery. The anther
becomes a dry structure and pollen are liberated from
the anther to the environment by dehiscence of the
anther.
MICROSPOROGENESIS
6. THE OVULE
Ovule is the inner part of ovary.
Parts of a mature ovule:
Integuments
Two layers of protective coating.
Micropyle
Minute pore or opening through which
the pollen tube enters.
Nucellus
Nutritive tissue lining the interior of the ovule.
Embryo sac
In the centre of nucleus, it contain seven cells-
Three cells at the micropylar end- one egg cell
and two synergids.
Three cells at opposite end, called antipodal cells.
One large central cell. The central cell is different containing two nuclei
called polar
nuclei.
7. MEGASPOROGENESIS
The megaspore mother cell (diploid cell ) divides meiotically to form
four megaspores. Out of these megaspores, three degenerates and
one remain functional. The functional megaspores divide mitotically to
form 2-celled embryo sac. Further subsequent mitotic division finally
forms 8- celled embryo sac.
Six of the eight nuclei are surrounded by cell walls and organized
into cells; the remaining two nuclei, called polar nuclei are situated in
the large central cell. Three cells at the micropylar end forms the egg
apparatus. The egg apparatus is made up of two synergids and one
egg cell. Three cells at the chalazal end is known as antipodal. So, the
mature embryo sac is 7 celled and 8 nucleated.
8. Germination of Pollen Grain
Pollen grain germinates only if it falls on the stigma of the same plant
species, otherwise, it disintegrates.
The pollen grain on reaching to the stigma absorb nutrients secreted by the
stigma and the pollen tube begins to grow.
The tube nucleus remains close to the growing tip of the pollen tube and
eventually disintegrates.
Meanwhile, Generative nucleus divides into two male gametes or nuclei
which move to the tip of the tube and lie in the mass of cytoplasm.
9. The tube then turns toward the micropyle, passes inwards through it, and
finally reaches the embryo sac, close to the egg cell.
After pollen tube penetrates into the tip of the tube dissolve and the male
gametes are set free inside the ovule.
One male gametes fuses with the egg and forms the fertilized egg and or
the zygote.
The second male gamete fuses with the secondary nucleus (definitive
nucleus) i.e, the nucleus formed by the fusion of the polar nuclei and forms
the endosperm nucleus. The fusion of male gamete with the two polar nuclei
is often termed as triple fusion.
The zygote develops into the embryo, while the endosperm nucleus
develops into endosperm of the seed.
12. Double Fertilization
In flowering plants , two sets of fertilization takes place. One occurs
between the sperm nucleus and the egg cell, while the other takes place
between the second sperm cell and the definitive nucleus. Thus,
fertilization in flowering plants is referred to as double fertilization.
If, for some reason, the egg cell fails to fertilize, the synergids (also
called help cells) assume the role of the egg cell. In case fertilization
occurs between the egg cell and male nuclei, the synergids disintegrates
soon after fertilization. Antipodal cells also have no positive role. There
also get disorganized, sometimes even before fertilization.
13.
14. Post fertilization
After fertilization, the egg cell surrounds itself with a cell wall and is known as
the oospores.
The ovary enlarges to form the fruit and the ovarian wall forms the fruit wall,
The ovules becomes the seed.
A fruit may contain one or more seeds. When the fruit is ripe, the seeds
contained within the fruit is released by one of the various methods of dispersal
and grow into a new plant under suitable conditions.