A vertebrate is an animal with a spinal cord surrounded by cartilage or bone. The word comes from vertebrae, the bones that make up the spine. Animals that are not vertebrates are called invertebrates. Vertebrates include birds, fish, amphibians, reptiles, and mammals
ORIGIN OF CHORDATES
Animal kingdom is basically divided into two sub kingdoms:
Non-chordata- including animals without notochord.
Chordata- This comprising animals having notochord or chorda dorsalis.
Chordates were evolved sometime 500 million years ago during Cambrian period (invertebrates were also began to evolve in this period) .
Chamberlain (1900) pointed out that all modern chordates possess glomerular kidneys that are designed to remove excess water from body.
It is believed that Chordates have originated from invertebrates.
It is difficult to determine from which invertebrate group the chordates were developed.
Chordate ancestors were soft bodied animals. Hence they were not preserved as Fossils.
However, early fossils of chordates have all been recovered from marine sediments and even modern protochordates are all marine forms.
Also glomerular kidneys are also found in some marine forms such as myxinoids and sharks. That makes the marine origin of chordates more believable.
Chordates evolved from some deuterostome ancestor (echinoderms, hemichordates, pogonophorans etc.) as they have similarities in embryonic development, type of coelom and larval stages.
Many theories infers origin of chordates, hemichordates and echinoderms from a common ancestor.
A vertebrate is an animal with a spinal cord surrounded by cartilage or bone. The word comes from vertebrae, the bones that make up the spine. Animals that are not vertebrates are called invertebrates. Vertebrates include birds, fish, amphibians, reptiles, and mammals
ORIGIN OF CHORDATES
Animal kingdom is basically divided into two sub kingdoms:
Non-chordata- including animals without notochord.
Chordata- This comprising animals having notochord or chorda dorsalis.
Chordates were evolved sometime 500 million years ago during Cambrian period (invertebrates were also began to evolve in this period) .
Chamberlain (1900) pointed out that all modern chordates possess glomerular kidneys that are designed to remove excess water from body.
It is believed that Chordates have originated from invertebrates.
It is difficult to determine from which invertebrate group the chordates were developed.
Chordate ancestors were soft bodied animals. Hence they were not preserved as Fossils.
However, early fossils of chordates have all been recovered from marine sediments and even modern protochordates are all marine forms.
Also glomerular kidneys are also found in some marine forms such as myxinoids and sharks. That makes the marine origin of chordates more believable.
Chordates evolved from some deuterostome ancestor (echinoderms, hemichordates, pogonophorans etc.) as they have similarities in embryonic development, type of coelom and larval stages.
Many theories infers origin of chordates, hemichordates and echinoderms from a common ancestor.
The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species.
It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body.
In some chordates, the notochord acts as the primary axial support of the body throughout the animal's lifetime.
The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species.
It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body.
In some chordates, the notochord acts as the primary axial support of the body throughout the animal's lifetime.
Reptiles are tetrapod animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of modern amphibians, is called herpetology.
Transitional forms chapter 2.3 mammal ancestors morganucodon to platypus ...SantoshBhatnagar1
IT IS BILINGUAL PRESENTATION OF STRIKING SPECIAL FEATURES OF ANCESTORS OF MODERN MAMMALS ALONG WITH THEIR PICTORIAL DEPICTION ARRANGED .CHRONOLOGICALLY .
Transitional forms Chapter 6 ancestors of chordates vertebrates fishes eng...SantoshBhatnagar1
IT IS AN INTERESTING STORY OF EVOLUTION OF CHORDATES ,WITHIN THEM VERTEBRATES AND WITHIN THEM FIRST FISHES -THEN OTHERS -ENTRIE PROCESS STARING FROM A SAND PARTICLE LIKE SACCORHYTUS .
Phylum Mollusca-my report..
sorry for some overlapping of texts... i was not able to edit it..it is actually because of the animations that i put it..... i just uploaded it directly :)
IT IS A LIST OF
WONDERS OF NATURE SERIES OF BOOKS PUBLISHED BY ME ON WEEBLY.COM .
SOME OF THESE BOOKS ARE ON SCRIBD.COM AND SOME ON SLIDE SHARE .NET AS WELL;
ALL COVER SCIENTIFIC TOPICS; 2 BOOKS ARE IN ENGLISH AND REST IN BILINGUAL ( ENGLISH/HINDI ) FORMAT ;
ALL IN SEMI POETIC STYLE
MANY ARCHAEA ARE EXTREMOPHILES SOME ARE HALOPHILIC, BUT SOME ARE HYPERHALOPHILIC ,SOME ARE ALKALOPHILIC SOME HYPER ALKALOPHILIC BUT SOME ARE DOUBLE EXTREMOPHILES BEING HYPER HALO ALKALIPHILIC LIKE NATRIALBA -A FACULTATIVE ANAEROBE WHICH IS EXOELECTROGEN AS WELL AND CAN PRODUCE ELECTRICITY IN SUNLIGHT AS WELL AS MFC .
MANY ARCHAEA & BACTERIA ARE EXTREMOPHILES BUT SOME ARCHAEA ARE HYPER THERMOPHILES LIKE SULFOLOBALES DISCOVERED FIRST IN SOLFATANA VOLCANO ITALY AND LATER IN MANY HOT SPRINGS AND HOT MUD POOLS
THEY HAVE SPECIAL STRUCTURE AND METABOLISM TO BE ABLE TO SURVIVE AT 70-85 C MAIN THING IS THEY CAN GENERATE ELECTRICITY EVEN AT 80 C IN MFC
INTERESTINGLY THEY HAVE BEEN SELECTED FOR SPACE TRIPS BY NASA .
CHLAMYDOMONAS IS A WONDERFUL ORGANISM KNOWN FOR ITS MANY FEATURES AND QUALITIES ;BUT THESE DAYS IT IS IN NEWS MAINLY FOR ITS ABILITY TO CONVERT LIGHT INTO ELECTRICITY DIRECTLY IN ITS
' EYE ' AND IN MFC ;HERE WE HAVE FOCUSED ON TRANSFER OF ELECTRONS OBTAINED FROM PHOTOSYNTHETIC REACTIONS TO ANODES INMFC
EXOELECTROGENS ARE ELECTROACTIVE ORGANISMS CAPABLE OF TRANSFERING ELECTRONS OUTSIDE THEIR CELLS
PYROCOCCUS IS ONE SUCH MICROORGANISM -A HYPERTHERMOPHILE CAPABLE OF TRANSFERING ELECTRONS TO ANODES AND PRODUCE ELECTRICITY EVEN AT 90C IT IS A UNIQUE ORGANISM IN MANY RESPECTS
EXOELECTROGENS ARE CAPABLE OF EXPORTING ELECTRONS OUT OF THEIR CELLS AND HAVE GREAT AFFINITY WITH ELECTRODES;HENCE THEY TRANSFER EXCESS ELECTRONS PRODUCED DURING PHOTOSYNTHESIS OR RESPIRATION .MANY BACTERIA AND ALGAE ARE ELECTRO ACTIVE AND MACRO ALGAE ARE ONE OF THEM AND HAVE BEEN FOUND TO BEMORE EFFICIENT THAN BACTERIA AS EVIDENT FROM THE EXPERIMENTS BY SHLODBERG ON ULVA.
EXO ELECTROGENIC SPECIES ARE FOUND IN MANY GENERA OF EUKARYOTIC AS WELL AS PROKARYOTIC ORGANISMS ;BUT BACTERIA ,PARTICULARLY CYANOBACTERIA AND PHOTOSYNTHETIC EUKAROTES LIKE ALGAE AREIN THE FOREFRONT - BOTH MICRO AMD MACRO ALGAE ARE BEING UTILISED WITH OR WITHOUT BACTERIA IN MFCs FOR TREARING POLLUTED WATER AND SIMULTANEOUS PRODUCTION OF ELECTRICITY -THE ADVANTAGE WITH ALGAE IS THEY SUCK IN CO2 AND GIVE OUT O2 AND ARE THUS
BETTER FOR ENVIRONMENT
NITZCHIA IS A LARGE GENUS OF DIATOMS WHICH INCLUDES BOTH FRESH WATER AND MARINE SPECIES -MANY TOXIC ALSO;BUT THEY ALSO SERVES AS GOOD BIOSENSORS MAINLY DUE TO THEIR BIOLUMINESCENT POROUS SILICON FRISTULE
DIATOMS LIKE NITZSCIA ARE ALSO PREFERRED DUE TO THEIR OIL PRODUCTION AND OTHER USES OF THEIR FRISTULE
EXOELECTROGENS ARE ORGANISMS
WHICH CAN RECEIVE ELECTRONS FROM DONARS AND CAN EXPORT
ELECTRONS OUTSIDE THE CELL OR CELLS
THE ELECTRONS PRODUCED DURING PHOTOSYNTHESIS OR RESPIRATION AVAILABLE TO THEM CAN BE PASSED ON TO ELCTRON ACCEPTORS VIA ELECTRODES AND DURING THE PROCESS ELECTRICITY GETS GENERATED IN THE CIRCUIT .
THE CHALLENGE IS TO EXTRACT ELECTRONS AND USE THEM FOR POWER GENERATION AS WELL AS SIMULTANEOUSLY CLEAN POLLUTED WATER AND PRODUCE HYDROGEN ETC AND OTHER BY PRODUCTS .
CYANOBACTERIA ARE ONE MOST OF THE MOST FAMOUS BACTERIA -KNOWN FROM PRECAMBIAN DAYS AND DISTINGUISHED AS MULTITASK MASTERS -EARLIER CONSIDERED RESPONSIBLE FOR OXYGENATED ATMOSPHERE WHERE AEROBICS FLOURISHED AND FOR NITROGEN FIXING ABILITIES BUT KNOW VALUED EQUALLY FOR THEIR CONVERTINF LIGHT ENERGY INTO ELECTRICAL ENERGY ;AND ALSO FOR CAPABILITY TO PRODUCE HYDROGEN AND ORGANICS LIKE ETHANOL ETC
SHEWANELLA - VERSATILE EXOELECTROGENIC FACULTATIVE ANAEROBE CAPABLE OF GENERATING ELECTRICITY BY REDUCING MANY METALS WHILE RESPIRING AND TRANSFERING ELECTRONS EXTRACELLULARLY
HENCE THEIR BIOFILMS AREUSED IN MFCs,MECs. ;KNOWN FOR THRIVING ON A VARIETY OF SUBSTRATES AND REDUCING MANY NOBLE METALS LIKE GOLD SILVER PLATINUM ETC ; ALSO CAPABLE OF PRODUCING HYDROGEN AND H2S; ALSO FAMOUS FOR BIOSYNTHESIS OF NANOPARICLES ;PRAISED FOR EFFICIENCY OF ITS NANOWIRES AND BIOFILMS ; CAN GENERATE ELECTRICITY FROM WASTE ALSO;HENCE SELECTED FOR DEEPSPACE RESEARCH -COULD SOLVE ASTRAUNOTS URINE DISPOSAL PROBLEM AS IT CAN MAKE IT REUSABLE WHILE PROVIDING POWER TO SATELLITE;IT IS ALSO INFAMOUS FOR SPOILING FOOD-FISH MEAT ETC AND CAUSING DISEASES IN HUMANS .
GEOBACTER IS ONE OF THE MOST FAMOUS EXOELECTROGENIC BACTERIA WHICH WAS THE FIRST BACTERIUM DISCOVERED WITH CAPABLITY OF OXIDISING ORGANIC COMPONDS AND METALS( INCLUDING RADIOACTIVE METALS AND PETROLEUM COMPOUNDS )INTO CO2 USING IRONOXIDE ETC AS ELECTRON ACCEPTOR AND PRODUCING ELECTRIC CURRENT. ITHAS BEEN USED IN VARY MANY EXPERIMENTS TO TEST THE WONDERFUL QUALITIES, ABILITIES AND CAPABILITIES OF VERSATILE EXOELECTROGENS AND THEIR USE FOR BIOREMEDIATION AND BIOFUEL PRODUCTION., THEY ARE ALSO CAPABLE OF RESPIRING ON GRAPHITE ELECTRODES
EXOELECTROGENS ARE VERSATILE HEROES CAPABLE OF SIMULTANEOUSLY DELIVERING MULTIPLE BENEFITS TO US INVARIOUS FIELDS RANGING FROM BIOREMEDIATION TO ENERGY,ENVIRONMENT, SENSORS, CLEAN BIO FUELS DESALINATION,Etc AND ARE POISED TO SOLVE OUR WASTE DISPOSAL PROBLEM EVEN IN SPACE.
ONE FEALS LIKE SALUTING THEM FOR THEIR MULTIPLE TALENTS.
THEY INCLUDE MAINLY BACTERIA BUT ALSO MICRO ALGAE, FUNGI,AND EVEN SOME ANGIOSPERMS .
EXOELECTROGENS ARE ORGANISMS WHICH ARE CAPABLE OF SENDING EXCESS ELECTRONS OUT OF THE CELL TO AN ULTIMATE ELECTRON ACCEPTOR . THE MOST FAMOUS EXOELECTROGENS INCLUDE GEOBACTER & SHEWANELLA BACTERIA. THEIR THESE QUALITIES ARE BEING USED IN MICROBIAL FUEL CELLS .
THEIR APPLICATION FOR PRODUCING ELECTRICITY FROM WASTEWATERS BIOREMEDIATION
CHAMPIONS OF THE PLANT KINGDOM - CONTENTS SNIP.docxSantoshBhatnagar1
HERE 'PLANT KINGDOM' HAS BEEN USED IN LARGER SENSE TO INCLUDE NOT ONLY PLANTAE BUT ALSO PROTISTA FUNGI BACTERIA AND LICHENS AND EXTENDED TO INCLUDE EVEN THE ENEMIES OF ALL LIVING BEINGS -THE VIRUSES .
CHAMPION FUNGI -PHELLINUS ELLIPSOIDEUS - LARGEST FRUITING BODY - SNIP PD.docxSantoshBhatnagar1
PHELLINUS ELLIPSOIDEUS PREFERS INFECTING DRYING OR DRY LOGS OF WOOD AND IS KNOWN FOR ITS UNUSUALLY LARGE FRUITING BODY WHICH HAS PROVED TO BE THE LARGEST IN THE WORLD
'AND IS CAPABLE OF RELEASING OR RATHER SHOWERING A TRILLION SPORES FROM MILLIONS OF PORES PER DAY.
VIRUSES ARE NOT CONSIDERED LIVING BEINGS BUT EVEN IF THEY WERE THEY WOULD NOT FIT IN ANY KINGDOM ;THEY ARE ACTUALLY ENEMIES OF ALL KINGDOMS OF LIVING BEINGS;
HENCE I WAS INITIALLY RELUCTENT TO INCLUDE THEM IN ABOOK ABOUT LIVING BEINGS BUT THEN I THOUGHT WITHOUT THEM THE STORY OF LIVING BEINGS IS NOT COMPLETE ;FURTHER THEY ARE NOT TREATED AS LIVING BY OUR DEFINITION OF LIFE AND LIVING BEINGS OTHERWISE THEY HAVE MANY CHARCTERISTICS OF BEINGS AND ARE WORTHY OF DUE CONSIDERATION AND FIT INTO OUR DEFINITION OF CHAMPIONS
AMONGST VIRUSES PITHO VIRUSESARE LARGEST AND MOST ANCIENT AND WITH MANY INTERESTING FEATURES .
IT IS A PRAYER INCORPORATING THANKS TO CHAMPION OFCHAMPIONS- LORD VISHVKARMA -GREAT GOD WHO CREATED THIS UNIVERSE AND SCOPE OF CHANPIONSHIP TO EACH CLASS AND CATEGORY OF LIVING BEINGS
IT IS INTERESTING TO KNOW THAT THERE ARE TWO CLAIMENTS FOR THE TITLE OF SMALLEST BACTERIA
AND BOTH ARE RIGHT IN THEIR OWN
WAY - MYCOPLASMA AS A PARASITE AND PELAGIBACTER AS A SELF SUFFICIENT ORGANISM .
BACTERIA ARE THEMSELVES MICROORGANISMS BUT THEY AREOF DIFFERENT SIZES AND MYCOPLASMA ARE SMALLEST PARASITIC BACTERIA;THEY ARE HOWEVER MORE KNOWN OR FEARED DUE TO THEIR PARASITIC NATURE.PARTICULARLY THEIR VARIETIES WHICH CAUSE SERIOUS DISEASES IN HUMANBEINGS.
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.
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.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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 .
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.
(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.
Transitional forms chapter 7 hemichordates and nonchordates english
1. Transitionalforms Chapter 7 Hemichordates
Enteropneust Acorn worm
NOAA – Wc – Public domain
We are extraordinary
worm like organisms
with some features of chordates
and some of non chordates
Very long tube like creatures
at home in the sand underneath
shallow waters of intertidal zone
leading life quietly in our burrows
2. Transitionalforms
Although we resemble non chordates
mainly worms , we possess gills
and notochord as well justifying our
being considered hemichordates.
We have a long body with skin
all covered with mucus and cilia
a long proboscis and a collar to boast
and gills to breath like fish
We have neither eyes nor ears
our mouth is on collar & not on tip
we move sluggishly with the help
of cilia ,and also eat with their help
Like earthworms eating detritus
we gulp it mixed with sand
a heart which acts also as a kidney.
is also our unusual feature .
Our evolutionary significance
lies in our being an intermediate form
linking chordates and non chordates
surviving from about 500 Mya till date .
4. Transitionalforms
These beautiful jellies
are not jelly fishes
but like them dangerous
voracious predators
With eight Comb rows of
fused cilia and tentacles
armed with sticky cells
called Colloblasts
Some of their most delightful
features include not only
their soft body of varied shapes
and colours of various hues
but changing rainbow colours
produced by synchronously
beating cilia of their multiple combs
propelling them ahead in waters
Not only that most of them
are bioluminescent as well
producing blue or green light seen
shining at various depths in all seas.
5. Transitionalforms non chordates
Peripatus- Onycophora
Velvet worms
Geoff Gallice – Flickr – Wc –cc
These elongate ,soft , many legged ,wormiform
creatures, looking like slugs or caterpillars
with stubby ,baggy, hollow feet bearing claws
are known for curious reproductive behavior
The males produce Phermones to attract
females - some of which produce eggs
while others bear young ; not only that
many store sperms inside for some time.
While some males deposit sperms in female genitals
others stick them anywhere on female body
yet others carry sperms on a spiky spiny or pitted head
and abutt the spermatophore against females genitals.
6. Transitionalforms Monoplacophora
Neopilina - a living fossil
Funk monk – Wc - cc
They say we are living fossils
for we are the only ones still living
members of a genus of Paleozoic vintage
which flourished in the Cambrian times
Our soft body is capped with
a single dome shaped shell
and we have paired multiple organs
arranged in a series inside
7. Transitionalforms
Our nephridia heart and gills
are repeated serially as in
annelids orarthropoda;but we are
limpet like molluscs of the deep sea
Exhibiting relationship of Molluscs
with arthropoda on one hand and
annelids on the other;but whether we are
a linking form is still an open question.
8. Transitionalforms Protista
Proterospongia
Mateus Zica – Wc – cc
I am a single celled organism
known for my collar and flagellum
forming colonies of stylish designs
and forms, inhabiting fresh waters
I am a choanoflagellate
famous as a linking form
between protozoa and porifera as
I exhibit similarities with sponges .
My real importance ,however, lies
in the innovation of cell signaling
and cell adhesion , (essential for evolution of
multicellularity ), before evolution of animals.
