The document outlines the history and development of the cell theory. It discusses early discoveries of cells in the 1600s by Hooke and Leuwenhoek. The cell theory was then developed between 1838-1858 by Schleiden, Schwann, and Virchow, establishing that all organisms are composed of cells, cells are the basic unit of life, and cells only come from preexisting cells. The modern cell theory adds that cells contain DNA, have similar chemical composition and functions, and their activity depends on internal structures. The cell theory is now fundamental to medicine, health research, and understanding that humans are communities of living cells.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
This PowerPoint, designed by East Stroudsburg University student Kristen O'Connor, is a PowerPoint designed for middle school science students on cell organelles.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
This PowerPoint, designed by East Stroudsburg University student Kristen O'Connor, is a PowerPoint designed for middle school science students on cell organelles.
INTRODUCTION TO CELLS
INTRODUCTION TO CELL THEORY
HISTORY
FORMULATION OF CELL THEORY
CLASSICAL CELL THEORY
DRAWBACKS OF CLASSICAL THEORY
MORDEN CELL THEORY
EXCEPTION OF CELL THEORY
SIGNIFICANCE OF CELL THEORY
HOW HAS THE CELL THEORY BEEN USED
CONCLUSION
INTRODUCTION
HISTORY
ORIGIN OF LIFE
THEORY OF ETERNITY
THEORY OF SPECIAL CREATION
THEORY OF SPONTANEOUS GENERATION
CELL THOERY
MODERN CELL THEORY
EXCEPTION OF CELL THEORY
CONCLUSION
REFERANCES
Cell theory, fundamental scientific theory of biology according to which cell...jungutierrez8
Cell theory, fundamental scientific theory of biology according to which cells are held to be the basic units of all living tissues. First proposed by German scientists Theodor Schwann and Matthias Jakob Schleiden in 1838, the theory that all plants and animals are made up of cells marked a great conceptual advance in biology and resulted in renewed attention to the living processes that go on in cells.
Introduction to Cell. Cell is the basic unit of life. Every living things are composed of cells..........................................................................................................................................................................................
Richard's aventures in two entangled wonderlandsRichard 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.
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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
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.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
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.
2. Some Random Cell FactsSome Random Cell Facts
The average human being is composedThe average human being is composed
of around 100 Trillion individual cells!!!of around 100 Trillion individual cells!!!
It would take as many as 50 cells toIt would take as many as 50 cells to
cover the area of a dot on the letter “cover the area of a dot on the letter “ii””
WOW!!!WOW!!!
3. Discovery of CellsDiscovery of Cells
1665- English Scientist, Robert Hooke, discovered1665- English Scientist, Robert Hooke, discovered
cells while looking at a thin slice of cork.cells while looking at a thin slice of cork.
He described the cells as tiny boxes or a honeycombHe described the cells as tiny boxes or a honeycomb
He thought that cells only existed in plants and fungiHe thought that cells only existed in plants and fungi
4. Anton van LeuwenhoekAnton van Leuwenhoek
1673- Used a handmade microscope to observe1673- Used a handmade microscope to observe
pond scum & discovered single-celled organismspond scum & discovered single-celled organisms
He called them “animalcules”He called them “animalcules”
He also observed blood cells from fish, birds, frogs,He also observed blood cells from fish, birds, frogs,
dogs, and humansdogs, and humans
Therefore, it was known that cells are found inTherefore, it was known that cells are found in
animals as well as plantsanimals as well as plants
5. 150-200 Year Gap???150-200 Year Gap???
Between the Hooke/Leuwenhoek discoveriesBetween the Hooke/Leuwenhoek discoveries
and the mid 19and the mid 19thth
century, very little cellcentury, very little cell
advancements were made.advancements were made.
This is probably due to the widely accepted,This is probably due to the widely accepted,
traditional belief in Spontaneous Generation.traditional belief in Spontaneous Generation.
Examples:Examples:
-Mice from dirty clothes/corn husks-Mice from dirty clothes/corn husks
-Maggots from rotting meat-Maggots from rotting meat
6. 1919thth
Century AdvancementCentury Advancement
Much doubt existed around Spontaneous GenerationMuch doubt existed around Spontaneous Generation
Conclusively disproved by Louis PasteurConclusively disproved by Louis Pasteur
Pasteur: Ummm, I
don’t think so!!!
+
=
?
7. Development of Cell TheoryDevelopment of Cell Theory
1838- German Botanist, Matthias Schleiden,1838- German Botanist, Matthias Schleiden,
concluded that all plant parts are made of cellsconcluded that all plant parts are made of cells
1839- German physiologist, Theodor Schwann,1839- German physiologist, Theodor Schwann,
who was a close friend of Schleiden, stated thatwho was a close friend of Schleiden, stated that
all animal tissues are composed of cells.all animal tissues are composed of cells.
8. Development of Cell TheoryDevelopment of Cell Theory
1858- Rudolf Virchow, German physician,1858- Rudolf Virchow, German physician,
after extensive study of cellular pathology,after extensive study of cellular pathology,
concluded that cells must arise fromconcluded that cells must arise from
preexisting cells.preexisting cells.
9. The Cell Theory CompleteThe Cell Theory Complete
The 3 Basic Components of the Cell TheoryThe 3 Basic Components of the Cell Theory
were now complete:were now complete:
1. All organisms are composed of one or more1. All organisms are composed of one or more
cells. (Schleiden & Schwann)(1838-39)cells. (Schleiden & Schwann)(1838-39)
2. The cell is the basic unit of life in all living2. The cell is the basic unit of life in all living
things. (Schleiden & Schwann)(1838-39)things. (Schleiden & Schwann)(1838-39)
3. All cells are produced by the division of3. All cells are produced by the division of
preexisting cells. (Virchow)(1858)preexisting cells. (Virchow)(1858)
10. Modern Cell TheoryModern Cell Theory
Modern Cell Theory contains 4 statements, inModern Cell Theory contains 4 statements, in
addition to the original Cell Theory:addition to the original Cell Theory:
The cell contains hereditary information(DNA) whichThe cell contains hereditary information(DNA) which
is passed on from cell to cell during cell division.is passed on from cell to cell during cell division.
All cells are basically the same in chemicalAll cells are basically the same in chemical
composition and metabolic activities.composition and metabolic activities.
All basic chemical & physiological functions areAll basic chemical & physiological functions are
carried out inside the cells.(movement, digestion,etc)carried out inside the cells.(movement, digestion,etc)
Cell activity depends on the activities of sub-cellularCell activity depends on the activities of sub-cellular
structures within the cell(organelles, nucleus, plasmastructures within the cell(organelles, nucleus, plasma
membrane)membrane)
11. How Has The Cell Theory Been Used?How Has The Cell Theory Been Used?
The basic discovered truths about cells, listedThe basic discovered truths about cells, listed
in the Cell Theory, are the basis for thingsin the Cell Theory, are the basis for things
such as:such as:
Disease/Health/Medical Research and Cures(AIDS,Disease/Health/Medical Research and Cures(AIDS,
Cancer, Vaccines, Cloning, Stem Cell Research, etc.)Cancer, Vaccines, Cloning, Stem Cell Research, etc.)
12. Some Parting ThoughtsSome Parting Thoughts
It is amazing to think that the cells that makeIt is amazing to think that the cells that make
up our bodies are just as alive as we are.up our bodies are just as alive as we are.
Humans are just an intricately designedHumans are just an intricately designed
community of cells, which must work togethercommunity of cells, which must work together
to surviveto survive
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