This document provides information about embryology of angiosperms. It discusses the key topics in plant embryology including microsporogenesis, megasporogenesis, pollination, fertilization, and embryo development. The history of embryology is explored beginning with Aristotle and Theophrastus in ancient Greece. Important later figures who advanced the understanding of plant sexuality and reproduction are mentioned like Nehemiah Grew, R.J. Camerarius, and J.G. Kolreuter. The structures of the anther and pollen grain are described along with the development of the male gametophyte within the pollen.
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
This slide shows the information about gameophyte.
there are two type of gametophyte
1) male gameetophyte
2)female gametophyte
we only discussed about the female gametophyte. it has megagametogenesis and different kind of embryo secs and their discription are also their in the slide.
description of different types of reproductive organs, developmental stages and process of reproduction in Cycas. Various internet sources have been used.
Wall layers of anther have different functions most importantly they help in providing nutrition to developing pollens and also help in anther dehiscence.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
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
This slide shows the information about gameophyte.
there are two type of gametophyte
1) male gameetophyte
2)female gametophyte
we only discussed about the female gametophyte. it has megagametogenesis and different kind of embryo secs and their discription are also their in the slide.
description of different types of reproductive organs, developmental stages and process of reproduction in Cycas. Various internet sources have been used.
Wall layers of anther have different functions most importantly they help in providing nutrition to developing pollens and also help in anther dehiscence.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
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.
This upload includes description of structure of microsporangium, microsporogenesis, pollen grain and megasporogenesis.
It will be helpful to the students for their quick reference.
Are we not lucky that plants reproduce sexually? The myriads of flowers that we enjoy gazing at, the scents and the perfumes that we swoon over, the rich colours that attract us, are all there as an aid to sexual reproduction. Flowers do not exist only for us to be used for our own selfishness. All flowering plants show sexual reproduction.
in this slide the chapter explanation is according to NCERT Syllabus which would be helping students in every field..
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
Development of male gametophyte
1. B.Sc.- II, Sem- III
Unit – VI
Embryology of Angiosperm
DR. SWATI PUNDKAR
ASSISTANT PROFESSOR
DEPARTMNET OF BOTANY
SHRI SHIVAJI SCIENCE COLLEGE,
AMRAVATI
2. .
Embryology is the study of structure and development of
embryo, including the structure and development of male
and female reproductive organs, fertilisation and similar
other processes.
Embryology played a significant role in consideration of
systemic botany.
Plant embryogenesis is a process that occurs after
the fertilization of an ovule to produce a fully developed
plant embryo
Plant embryology deals with study of all events starting
from microsporogenesis, megasporogenesis. Pollination
and fertilization till the development of mature embryo.
3. Fritillaria tenella and Lilium
martagon
Histrory
The Greek philosopher Aristotle (384-322 B.C.) is the
‘Father of the Study of Natural Sciences’.
Later Theophrastus (370-287 B.C), the ‘Father of Botany’
in third century B.C. referred the pollination of the date
palm. the nature of sexuality of plants was forgotten for
about 2,000 years and his report was considered as useless
Nehemiah Grew who first clearly stated, in 1682, that the
stamens are nothing but the male sex organs of a plant.
In 1694, R. J. Camerarius suggested that the anthers are
the male sex organs of a plant, while the ovaries with the
styles were the female sex organs.
J. G. Kolreuter (1761) fully confirmed the idea of
Camerarius.
5. Sexual reproduction
takes place with slight
variations in different
groups of plants.
Plants have two
distinct stages in their
lifecycle: the
gametophyte stage
and the sporophyte
stage.
8. A. Epidermis
It is the outermost layer of a young anther and undergoes only anticlinal divisions. It is single layered.
Function: It performs the role of protection.
B. Endothecium
Immediately below the epidermis, the cell layers are radially elongated and develop fibrous thickenings bands
which U shaped. These cells are hygroscopic in nature and help in dehiscence of anther and discharge of
pollen. It is generally single layered but some plants it may be multilayered.
C. Middle layer
Usually one to three middle layers are found below the endothecium. The cells are paremchymatous which
present between endothecium and tapetum from middle layer. These cells are ephemeral and degenerate completely
before pollen mother cell undergoes meiosis. (They become crushed at the time of meiotic division in the pollen.)
Function: The middle layers store the food material which is utilized by pollen mother cells.
9. Tapetum
The cells of the innermost parietal layer possess dense protoplasm and the food entering into
the sporogenous cells pass through it. Thus it serves as a nutritive layer for the developing
microspore. The tapetum may be glandular or amoeboid based on the behaviour of the cells
during sporogenesis.
Two types
1-Amoeboid or invasive or periplasmodial 2-Secretory or glandular tapetum
10.
11.
12.
13. 5. Tapetum is associated with the development of pollen grains
because when tapetum is degenerate before microsporogenesis,
the pollen grains produced are steril or abortive.
6. Pollen wall contains proteins derived from the gametophytes
as well as the tapetal cells. These proteins are responsible for
pollen allergy.
14. STRUCTURE OF POLLEN GRAINS
Tube cell, which will eventually become
the pollen tube, and a generative cell, which
contains the male sperm nuclei needed for
fertilization.
There are three main components of a pollen
grain. The inside of the grain is made up
of cytoplasm. This fluid medium houses the
aforementioned living cells, keeping them
moist and alive. The outer shell is made up of
two layers. The inside layer is aptly named
the intine (think interior). It is composed partly
of cellulose, a common component in the cell
walls of plant cells.
15. The tough outer layer is known as the exine (think exterior). This highly
sophisticated and complex outer layer is rich in a compound known
as sporopollenin.
On the surface of the pollen there is a sticky layer known as the pollen
coat or pollen kit, which is a rich source of proteins, lipids, vitamins,
phenolic compounds and minerals for the bees. The extent and chemistry
of pollenkit varies from species to species and the bees prefer pollen rich
in pollen kit.
18. Vegetative cell -
After pollen grains divide into two cells, the vegetative cell increases in size. The cell
organelles increase in number and size. Vegetative cells includes organelles such as
ribosomes, E.R., plastid, dictyosomes, and mitochondria. Nucleus is spherical or
irregular in outline containing chromosomes and one or two nucleoli. In mature stages
nucleus often lacks nucleolus.
19. Generative cell-
(A reproductive cell, especially a cell of an
angiosperm pollen grain that divides to
produce two male gamete nuclei)
Initially the generative cell is attached to intine
of the pollen wall but later on it gets detached
from the pollen wall. It lies free in the
cytoplasm of vegetative cell but there is no
cytoplasmic connection between two cells.
The generative cell cytoplasm contains the
organells Such as mitochondria, ribosomes,
endosplasmic reticulum, microtubule, and
dictyosomes (In the embryo sac, the double
fusion of the generative cells with the egg cell
and the two nuclei of the central cell give rise
to the diploid zygote and the triploid
endosperm, respectively.)
20. Formation of male gametes-
In the anthers of a flower, certain diploid cells undergo meiosis, forming
haploid spores (called microspores—"little spores"). These microspores
divide by mitosis to form two-celled pollen, consisting of a vegetative cell
and a generative cell. Or may be three celled (vegetative + 2 male
gamets) at time of release from the anther. When the pollen grain release
it landed on the stigma, The pollen grains has two cells (vegetative and
generative cell). The generative cell forms two gametes. These are non
motile. In angiosperms the female gametophyte (embryo sac) is situated
at distance from the stigma and to transport the male gamets pollen tube
is form. The pollen tube along with two male gamets grows down through
the style and enters the ovule for the process of fertilization.