About 20,000 species.
Eukaryotic cell and contain all the membrane bound organelles.
Thallus is green due to the presence of green pigment chlorophyll.
Chlorophyll is contained in chloroplast.
Pyrenoids embedded in chloroplast.
Cytoplasm contains vacuoles.
Motile cell of primitive forms contains eye spot or stigma.
Reserve carbohydrates are in the form of starch.
Cell wall invariably contains cellulose.
Produce motile reproductive bodies generally with two or four flagella.
Most are aquatic but some are subarial.
Several species of ulvales and siphonales are marine.
Some strains of chlorella are thermophilic.
Species of chlamydomonas and some chlorococcales occur in snow.
Coloechaete nitellarum is endophytic.
Cephaleuros is parasitic – cause ‘red rust of tea’.
Live epizoically on or endozoically within the bodies of lower animals – chlorella is found in hydra; chlorella beneath the scales of fish; characium on the antennae of mosquito.
Green algae in assosciation with the fungi constitute lichens.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
Agaricus is a genus of mushrooms containing both edible and poisonous species, with possibly over 300 members worldwide. The genus includes the common ("button") mushroom (Agaricus bisporus) and the field mushroom (A. campestris), the dominant cultivated mushrooms of the West.
• Gymnosperms (Gymnos = naked, Sperma = seed) include the small group of plants with naked seeds.
• The Gymnosperms originated in the Devonian period of the Paleozoic Era and formed the supreme vegetation in the Mesozoic Era.
About 20,000 species.
Eukaryotic cell and contain all the membrane bound organelles.
Thallus is green due to the presence of green pigment chlorophyll.
Chlorophyll is contained in chloroplast.
Pyrenoids embedded in chloroplast.
Cytoplasm contains vacuoles.
Motile cell of primitive forms contains eye spot or stigma.
Reserve carbohydrates are in the form of starch.
Cell wall invariably contains cellulose.
Produce motile reproductive bodies generally with two or four flagella.
Most are aquatic but some are subarial.
Several species of ulvales and siphonales are marine.
Some strains of chlorella are thermophilic.
Species of chlamydomonas and some chlorococcales occur in snow.
Coloechaete nitellarum is endophytic.
Cephaleuros is parasitic – cause ‘red rust of tea’.
Live epizoically on or endozoically within the bodies of lower animals – chlorella is found in hydra; chlorella beneath the scales of fish; characium on the antennae of mosquito.
Green algae in assosciation with the fungi constitute lichens.
This is a detailed presentation on Morphology, anatomy and reproduction of Marchantia spp. with high quality pics and eye capturing transitions and animations
Agaricus is a genus of mushrooms containing both edible and poisonous species, with possibly over 300 members worldwide. The genus includes the common ("button") mushroom (Agaricus bisporus) and the field mushroom (A. campestris), the dominant cultivated mushrooms of the West.
• Gymnosperms (Gymnos = naked, Sperma = seed) include the small group of plants with naked seeds.
• The Gymnosperms originated in the Devonian period of the Paleozoic Era and formed the supreme vegetation in the Mesozoic Era.
Ch 2 biological classification ppt , this ppt includes importance of classification and two kingdom , 3 and 4 kingdom classification along with five and 6 kingdom classification. Classification by R.H. Whittaker is discussed in detail.
Plant tissue system -Basis for plant anatomyPavan Rathod
i have explained about "plant tissue" in previous slideshare (hope you visited).in this presentation i have explained about "plant tissue system" ,it made easy to learn and classified to get better knowledge on concept.
it includes,epidermal tissue,trichomes ,stomata ,Development of stomata, Classification of stomata: based on development ,Classification of stomata: based on structure, shape and arrangements of subsidiary cell ,Agenous stomata, mesogenous stomata, Perigenous stomata ,Anomocytic stomata ,Anisocytic stomata,Diacytic stomata ,Paracytic stomata, Actinocytic stomata ,Gramineous stomata, root hairs, vasuclar tissue,xylem, Xylem vessel ,Tracheids, xylem Parenchyma,xylem fiber,phloem,Sieve tube, Companion cells ,phloem Parenchyma ,phloem Fibres,ground tissue, Cortex, Pericycle, Pericycle ,Pith..etc.
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 .
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 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.
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.
4. Systematic Position
• Class : Cyanophyceae
• Order : Oscillatoriales
• Family : Oscillatoriaceae
• Genus : Oscillatoria
5. Occurrence
• Found in moist places.
• Found in places rich in decaying organic
matter.
• It forms thin blue green coating on the surface
or edges of flowing water.
Common species
• Oscillatoria formosa
• O.princeps
6. Plant body –thallus
• Plant body consist of single row of cells
forming unbranched trichomes with a very
thin gelatinous sheath.
• Cells are broader than longer but cylindericalt.
• All cells are similar in trichome with the
exception of apical cells.(convex at the top)
• trichomes are usually naked and have a thin
poorly developed sheath.
7. Cell Structure
• The cell is prokaryotic in nature.
• A cell in the trichome is differentiated into two
parts
1. Cell wall:
• well developed.
2.Protoplasm:
• Have peripheral and central cytoplasm.
9. Reproduction
• SEXUAL REPRODUCTION.
No sexual reproduction present in
oscillatoria.
• VEGETATIVE REPRODUCTION.
Reproduction occur through vegetative parts.
Two methods
1. By harmogonia.
2. By fragmentation.
10. By Harmogonia.
• Harmogonia are the short segment of trichome
which consist of few cells.
Formation.
• Form by the formation of separation disc.
• Which are also called as necridia.
• The disc are formed by the death of one or more
cells of filament.
• These disc are mucilaginous,pad-like and
biconcave.
11. • The disc then absorb water and break into
small fragments.
• Form new oscillatoria under favourable
conditions.
12. By Fragmentation
• Accidental breakage of trichome cause
formation of small fragments.
• Which can develop into new oscillatoria.
13. Economic importance
• Help in reclamation of alkaline soil.
• Use as pollution indicator.
• Produce the greater amount of oxygen.
• Form symbiotic association with
protozoa,plant and fungi.
• Source of protein.(60% protein obtain from it)
• Help in nitrogen fixation.
