1. Plant embryogenesis begins with an asymmetric cell division forming an apical and basal cell, followed by further cell divisions forming a rudimentary plant body with an embryonic axis and cotyledons.
2. Key genes involved in embryo development establish the apical-basal and radial patterns, and mutations in these genes disrupt proper embryo formation.
3. In angiosperms, embryo development typically arrests after meristems and cotyledons form, with the seed coat enclosing the dormant embryo until germination conditions are met.
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
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
Plant fertilization is the union of male and female gametes (reproductive cells) to produce a zygote (fertilized egg)
Double Fertilization
Both the male gametes/sperms participate in sexual reproduction.
Two male gametes fuse with one female gamete wherein one male gamete fertilizes the egg to form a zygote, whereas the other fuses with two polar nuclei to form an endosperm
Triple fusion is the fusion of the male gamete with two polar nuclei inside the embryo sac of the angiosperm.
Porogamy - entry through the micropyle.
Chalazogamy - entry through the Chalaza
Mesogamy - entry through the middle part or the integuments
Steps leading to fertilization
Germination of the pollen grain:
Stigma function is to provide place of lodging and germination of the pollen grain after pollination.
Types of stigmas-
Wet stigmas
Secrete exudates like water and other nutrients
In the form of droplets on the stigma.
Exudates made up of a mix of water, lipids, sugars, amino acids, phenolic compounds.
Highly viscous and adhesive. Ex: Petunia, Zea etc.
Dry stigma
Do not secrete exudates Ex: Gossypium
Double Fertilization & Triple Fusion:
Both the male gametes are involved in the fertilization.
Fertilize two different components of the embryo sac - Double Fertilization
One fuses with the egg nucleus (syngamy) -> Zygote(2n)
second fuses with polar nuclei -> primary endosperm nucleus (PEN).
Involves fusion of three nuclei - Triple fusion -> Endosperm(3n)
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Discharge of pollen tube contents (two male gametes, vegetative nucleus and cytoplasm) into the synergids.
Disorganization of tube nucleus
Polyspermy &Heterofertilization
Heterofertilization - Type of double fertilization in plants in which endosperm and embryo are genetically different.
This happens when two different sperm nuclei from two different pollen tubes happen to enter the same embryo sac.
Dr. T. Annie Sheron
Annie Sheron
Kakatiya Government College
A general account of Quantitative (Multiple factor or Polygenic) Inheritance; Examples : Kernel colour in Wheat, Ear size (Cob length ) in Maize(Zea mays) ; Differences between Qualitative and Quantitative Inheritance
Biological assays are methods for the estimation of nature, constitution or potency of a material by means of the reaction that follows its application to living matter
Maternal effects are the influences of a mothers genotype on the phenotype of her offspring. It results from the asymmetric contribution of the female parent to the development of zygotes.
In terms of chromosomal genes, both male and female parents contribute equally to the zygote. The female parent contributes to the zygotes initial cytoplasm and organelles. Sperm rarely contribute anything other than chromosomes. Therefore zygotic development begins within a maternal medium and hence the maternal cytoplasm directly affects zygotic development.
Plant fertilization is the union of male and female gametes (reproductive cells) to produce a zygote (fertilized egg)
Double Fertilization
Both the male gametes/sperms participate in sexual reproduction.
Two male gametes fuse with one female gamete wherein one male gamete fertilizes the egg to form a zygote, whereas the other fuses with two polar nuclei to form an endosperm
Triple fusion is the fusion of the male gamete with two polar nuclei inside the embryo sac of the angiosperm.
Porogamy - entry through the micropyle.
Chalazogamy - entry through the Chalaza
Mesogamy - entry through the middle part or the integuments
Steps leading to fertilization
Germination of the pollen grain:
Stigma function is to provide place of lodging and germination of the pollen grain after pollination.
Types of stigmas-
Wet stigmas
Secrete exudates like water and other nutrients
In the form of droplets on the stigma.
Exudates made up of a mix of water, lipids, sugars, amino acids, phenolic compounds.
Highly viscous and adhesive. Ex: Petunia, Zea etc.
Dry stigma
Do not secrete exudates Ex: Gossypium
Double Fertilization & Triple Fusion:
Both the male gametes are involved in the fertilization.
Fertilize two different components of the embryo sac - Double Fertilization
One fuses with the egg nucleus (syngamy) -> Zygote(2n)
second fuses with polar nuclei -> primary endosperm nucleus (PEN).
Involves fusion of three nuclei - Triple fusion -> Endosperm(3n)
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Discharge of pollen tube contents (two male gametes, vegetative nucleus and cytoplasm) into the synergids.
Disorganization of tube nucleus
Polyspermy &Heterofertilization
Heterofertilization - Type of double fertilization in plants in which endosperm and embryo are genetically different.
This happens when two different sperm nuclei from two different pollen tubes happen to enter the same embryo sac.
Dr. T. Annie Sheron
Annie Sheron
Kakatiya Government College
A general account of Quantitative (Multiple factor or Polygenic) Inheritance; Examples : Kernel colour in Wheat, Ear size (Cob length ) in Maize(Zea mays) ; Differences between Qualitative and Quantitative Inheritance
Biological assays are methods for the estimation of nature, constitution or potency of a material by means of the reaction that follows its application to living matter
Maternal effects are the influences of a mothers genotype on the phenotype of her offspring. It results from the asymmetric contribution of the female parent to the development of zygotes.
In terms of chromosomal genes, both male and female parents contribute equally to the zygote. The female parent contributes to the zygotes initial cytoplasm and organelles. Sperm rarely contribute anything other than chromosomes. Therefore zygotic development begins within a maternal medium and hence the maternal cytoplasm directly affects zygotic development.
presentation on oogenesis of fertilisation process full details about it u will never find it anywhere else have full details about the ovum formation polar bodies and everything . so explore here
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
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
(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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
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.
2. 2
Embryo Development
Begins once the egg cell is fertilized
-The growing pollen tube
enters angiosperm embryo
sac and releases two sperm cells
-One sperm fertilizes central
cell and initiates endosperm
development (nutrients for embryo)
-Other sperm fertilizes
the egg to produce
a zygote
-Cell division soon
follows, creating
the embryo
3. 3
Plants differ from most animals in that embryogenesis does not directly generate
the tissues and organs of the adult. For example, angiosperm embryogenesis forms
a rudimentary plant body, typically consisting of an embryonic axis and two
cotyledons.
9. 9
Plant embryogenesis begins with an
asymmetric cell division, resulting in a
smaller apical (terminal) cell and a larger
basal cell.
Periclinally/anticlinally= 4 cell stage
14. 14
the apical-basal pattern (organization of organs along the apical-
basal axis) and the radial pattern (organization of the three basic
tissue systems - dermal, ground, and vascular).
The shoot apical
meristem
the root apical meristem
one or two cotyledons
are attached just below the shoot apical
meristem
the hypocotyl, followed by the
root, the root apical meristem, and the root
cap
16. 16
An outermost layer of epidermal cells (the epidermis) covers a cylinder
of cortical tissue (the cortex), which in turn overlies the vascular cylinder (the
endodermis, pericycle, phloem, and xylem) The protoderm is the meristem that
gives rise to the epidermis, the ground meristem produces the future cortex and
endodermis, and the procambium is the meristem that gives rise to the primary
vascular tissue and vascular cambium
19. 19
Genes involved in embryo development
mutants lacking body segments along the apical-basal axis. This class includes gurke
(gk), fackel (fk), monopterous (mp), and GNOM (gn)
showed a loss or distortion of the root, hypocotyl or cotyledon regions
mutants with disturbed radial symmetry - alterations of the radial pattern of tissue
layers. This class includes knolle (kn) and keule (keu)
mutants with disrupted organogenesis - these mutants have grossly abnormal overall
shapes, but have all of the pattern elements along the apical-basal and radial axes. This
class includes fass (fs), knopf (knf), and mickey (mic).
20. 20
GNOM gene
Seedlings homozygous for mutations in the GNOM gene lack both roots and
cotyledons. In the most extreme mutants, gnom embryos are
spherical and lack axial polarity entirely. We can conclude that GNOM gene
expression is required for the establishment of axial polarity
The MONOPTEROS gene:
Primary root and vascular tissue. Mutations in the MONOPTEROS (MP) gene
result in seedlings that lack both a hypocotyl and a root, although they do
produce an apical region. Thus the MP gene is required
for the formation of the embryonic primary root, but not for root formation in
the adult plant. The MP gene is important for the formation of vascular tissue in
postembryonic development
21. 21
Mutations in the KNOLLE (KN) gene affect the rate and plane of cell divisions as
well as cell morphology, resulting in mutant seedlings with a disturbed radial
organization of tissue layers. KN protein has similarity to syntaxins, a protein family
involved in vesicular trafficking
SHORT ROOT (SHR) and SCARECROW
(SCR), are necessary for tissue differentiation and cell differentiation not only in the
embryo, but also in both primary and secondary roots and in the hypocotyl.
FASS gene
is required for morphogenesis, i.e., oriented cell divisions and position-dependent
cell shape changes generating body shape, but not for cell polarity which seems
essential for pattern formation.
24. 24
-In many angiosperms,
development of the embryo
is arrested soon after
meristems and cotyledons
differentiate
-The integuments develop
into a relatively impermeable
seed coat
-Encloses the seed with its dormant
embryo and stored food
Seeds
25. 25
Pistils = One or more Carpels
Carpels = Stigma, Style & Ovary
The ovary wall is
termed the pericarp
-Has three layers: exocarp,
mesocarp and endocarp
-One, some, or all of these layers
develop to recognized fruit
Fruits can be:
-Dry or fleshy
-Simple (single carpel),
-Aggregate (multiple carpels),
-Multiple (multiple flowers)
Fruits = Pistils...During Seed Formation Flower
Develops into Fruit
26. 26
Germination
Germination is defined as the emergence of the
radicle (first root) from the seed coat
Germination begins when a seed absorbs water &
oxygen is available for metabolism
-Often requires an additional environmental
signal such as specific wavelength of light
28. 28
The first step in barley seed germination is imbibition. In this process, water penetrates the
seed coat and begins to soften the hard, dry tissues inside. The water uptake causes the
grain to swell up. The seed/fruit coat usually splits open allowing water to enter even faster.
The water begins to activate the biochemistry of the dormant embryo.
29. 29
The water coming into the seed and embryo dissolves a chemical made inside the
embryo. This chemical is called Gibberellic Acid (GA). It is a plant hormone, not too
different from steroids.
The dissolved GA is transported with the water through the rest of the seed tissues
until it arrives at the aleurone layer.
30. 30
The Gibberelic Acid which is transported by the water arrives at the aleurone layer.
The GA crosses into the cytoplasm of the aleurone cells and turns on certain genes in the
nuclear DNA. DNA is, of course, the hereditary molecule and contains the instructions for
making every protein needed for the survival of a barley plant. The precise mechanism of
how GA turns on the DNA is unknown at present. It is clear however that the mode of action
is to turn on just certain genes in the DNA.
The genes that are turned on are transcribed. The information archived in the DNA is
precious, so the aleurone cells make a disposable RNA copy of the gene that is turned on.
This disposable copy of the information, a kind of blueprint, is often called messenger RNA.
The process of making this RNA copy is called transcript
31. 31
he RNA that was made in the transcription process is transported into the cytoplasm of the aleurone cells.
In the cytoplasm, the messenger RNA joins up with a ribosome to begin the process of making a protein.
This process is often called protein synthesis or translation. In this process, the ribosome examines the
information held in the sequence of bases in the RNA. Transfer RNAs charged with particular amino acids
are moved into the position specified by the instructions in the messenger RNA, and the amino acids are
joined in a proper sequence by the ribosome. The sequence of amino acids determines the properties of the
protein being assembled.
In this case, the critical protein made with the information held in the RNA is amylase. This protein turns out
to be an enzyme of great importance.
The process of information held in the genes of DNA being transcribed into RNA and then translated into
protein constitutes the central dogma of genetics. You will want to remember later, that it is the signal of
Gibberellic acid that initiates this whole chain of events.
32. 32
A question one might ask right away is: from where do the amino acid building blocks for the amylase
come?
The answer is: from some other biochemistry in the aleurone cells. This biochemistry causes the
storage proteins in the aleurone cells to be digested by hydrolytic enzymes. The hydrolysis is
accelerated by enzymes known as proteases. These enzymes increase the rate at which the storage
protein is cut into individual amino acids.
The amino acids released by the hydrolysis are then free to be reassembled by the ribosomes into the
structure of amylase.
The same thing happens in people. You are not what you eat! You do not slowly become a steer by
eating beef. The protein in your hamburger is digested into amino acids. Those amino acids are then
reassembled into human proteins. Since the instructions for reassembling the amino acids come from
your human DNA, the proteins produced are human, not bovine!
33. 33
The amylase is secreted (transported out) from
the aleurone cells into the endosperm.
the cotyledon (or seed leaf). Since there is only
one, barley is a monocot.
the epicotyl (becomes the shoot)
the radicle (becomes the root)
35. 35
Embryo produces gibberellic acid
-This hormone signals the aleurone (outer
endosperm layer) to produce a-amylase
-Breaks down the endosperm’s starch into
sugars that are passed to embryo
Releasing Sugars From Cotyledon...So the
Embryo Can Grow
36. 36
Germination
New growth comes from delicate meristems
As the sporophyte pushes through the seed coat, it
orients with the environment such that the root grows
down & shoot grows up
-Usually, the root emerges before the shoot
-The shoot becomes photosynthetic, and the
postembryonic phase is under way
Cotyledons may be held above or below the ground
-May become photosynthetic or shrivel