Asexual reproduction is the production of new individuals from a single parent. This type of reproduction is generally observed in single-celled organisms. Here no fusion of gametes is involved and a single parent divides into two or more daughter cells. The offsprings produced are genetically and physically identical to the parent and are known as clones.
Somatic embryogenesis, in plant tissue culture 2KAUSHAL SAHU
Introduction
Types of somatic embryogenesis
Developmental stages
Factors affecting somatic embryogenesis
Importance
Conclusions
References
The process of regeneration of embryos from somatic cells, tissue or organs is regarded as somatic or asexual embryogenesis.
opposite of zygotic or sexual embryogenesis.
Embryo-like structures which can develop into whole plants in a way that is similar to zygotic embryos are formed from somatic cells.
This slideshow was created as a seventh-grade example of what a student might accomplish to give a presentation to the class or group of kids about sexual and asexual reproduction.
How Do Organisms Reproduce ? - Class 10 CBSE science (BIo)Amit Choube
Reproduction is an integral feature of all living beings. The process by which a living being produces its own like is called reproduction.
Importance of Reproduction:
Reproduction is important for each species, because this is the only way for a living being to continue its lineage. Apart from being important for a particular individual, reproduction is also important for the whole ecosystem. Reproduction helps in maintaining a proper balance among various biotic constituents of the ecosystem. Moreover, reproduction also facilitates evolution because variations come through reproduction; over several generations.
Somatic embryogenesis, in plant tissue culture 2KAUSHAL SAHU
Introduction
Types of somatic embryogenesis
Developmental stages
Factors affecting somatic embryogenesis
Importance
Conclusions
References
The process of regeneration of embryos from somatic cells, tissue or organs is regarded as somatic or asexual embryogenesis.
opposite of zygotic or sexual embryogenesis.
Embryo-like structures which can develop into whole plants in a way that is similar to zygotic embryos are formed from somatic cells.
This slideshow was created as a seventh-grade example of what a student might accomplish to give a presentation to the class or group of kids about sexual and asexual reproduction.
How Do Organisms Reproduce ? - Class 10 CBSE science (BIo)Amit Choube
Reproduction is an integral feature of all living beings. The process by which a living being produces its own like is called reproduction.
Importance of Reproduction:
Reproduction is important for each species, because this is the only way for a living being to continue its lineage. Apart from being important for a particular individual, reproduction is also important for the whole ecosystem. Reproduction helps in maintaining a proper balance among various biotic constituents of the ecosystem. Moreover, reproduction also facilitates evolution because variations come through reproduction; over several generations.
REPRODUCTION PROCESS IN ANIMALS AND MEN EXPLAINED COMPLETELY
CHECK FOR GOOD RESULTS
EXPLAINED WITH DIAGRAMS SEXUAL AND ASEXUAL REPRODUCTION]
TYPES OF REPRODUCTION,REGENERATION AND FRAGMENTATION ARE EXPLAINED BRIEFLY.
DNA REPRODUCTION,VEGTATIVE PROPAGATION AND POLLINATION PROCESS EXPLAINED
REPRODUCTION IN HUMAN BEINGS EXPLAINED FULLY FROM TOP TO BOTTOM
Before we discuss the mechanisms by which organisms reproduce,
let us ask a more basic question – why do organisms reproduce?
After all, reproduction is not necessary to maintain the life of an individual
organism, unlike the essential life processes such as nutrition,
respiration, or excretion. On the other hand, if an individual organism is
going to create more individuals, a lot of its energy will be spent in the
process. So why should an individual organism waste energy on a process
it does not need to stay alive? It would be interesting to discuss the
possible answers in the classroom!
Whatever the answer to this question, it is obvious that we notice
organisms because they reproduce. If there were to be only one, nonreproducing member of a particular kind, it is doubtful that we would
have noticed its existence. It is the large numbers of organisms belonging
to a single species that bring them to our notice. How do we know that
two different individual organisms belong to the same species? Usually,
we say this because they look similar to each other. Thus, reproducing
organisms create new individuals that look very much like themselves.
In this slide we explain the reproduction in Bacteria. here we explain the two basic types of reproduction briefly with their types. i,e
Sexual Reproduction
Asexual reproduction
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.
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/
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.
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.
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.
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 .
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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.
2. “ASEXUAL REPRODUCTION IS THE
MODE OF REPRODUCTION THAT
IS INVOLVED IN THE
PRODUCTION OF OFF SPRINGS
BY A SINGLE PARENT.”
3. WHAT IS ASEXUAL REPRODUCTION?
• Asexual reproduction is a mode of reproduction in
which a new offspring is produced by a single parent.
• The new individuals produced are genetically and
physically identical to each other, i.e., they are the
clones of their parent.
• Asexual reproduction is observed in both multicellular
and unicellular organisms.
4. • This process does not involve any kind of gamete fusion and
there won’t be any change in the number of chromosomes either.
• It will inherit the same genes as the parent, except for some
cases where there is a chance of rare mutation to occur
• Asexual reproduction is observed in both multicellular and
unicellular organisms.
• This process does not involve any kind of gamete fusion and
there won’t be any change in the number of chromosomes either.
• It will inherit the same genes as the parent, except for some
cases where there is a chance of rare mutation to occur.
5. CHARACTERISTICS OF ASEXUAL REPRODUCTION
1.Single parent involved.
2.No fertilization or gamete formation takes place.
3.This process of reproduction occurs in a very short
time.
4.The organisms multiply and grow rapidly.
5.The offspring is genetically similar.
7. BINARY FISSION
• The term “fission” means “to divide”.
• During binary fission, the parent cell divides into two
cells.
• The cell division patterns vary in different organisms,
i.e., some are directional while others are non-
directional.
• Amoeba and euglena exhibit binary fission.
8. • It is one of the simplest and uncomplicated methods
of asexual reproduction.
• The parent cell divides into two, each daughter cell
carrying a nucleus of its own that is genetically
identical to the parent.
• The cytoplasm also divides leading to two equal-
sized daughter cells. The process repeats itself and
the daughter cells grow and further divide.
9. • Step 1- Replication of DNA
• The bacterium uncoils and replicates its chromosome, essentially doubling its content.
• Step 2- Growth of a Cell
• After copying the chromosome, the bacterium starts to grow larger in preparation for
binary fissions. It is followed by an increase in cytoplasmic content. Another prominent
trait of this stage is that the two strands migrate to opposite poles of the cell.
• Step 3-Segregation of DNA
• The cell elongates with a septum forming at the middle. The two chromosomes are also
separated in this phase.
• Step 4- Splitting of Cells
• A new cell wall is formed at this phase, and the cell splits at the centre, dividing the
parent cell into two new daughter cells. Each of the daughter cells contains a copy of
the nuclear materials as necessary organelles.
10.
11. BUDDING
• Budding is the process of producing an individual
through the buds that develop on the parent body.
• Hydra is an organism that reproduces by budding.
• The bud derives nutrition and shelter from the parent
organism and detaches once it is fully grown.
12. BUDDING IN HYDRA
• Hydra is exclusively a freshwater organism having
different species.
• It is very small, just a half centimetre long.
• It is a cnidarian having a tubular body which is
composed of a head, distal end and afoot at the end.
13. • Budding in hydra involves a small bud which is
developed from its parent hydra through the
repeated mitotic division of its cells.
• The small bud then receives its nutrition from the
parent hydra and grows healthy.
• Growth starts by developing small tentacles and the
mouth.
• Finally, the small newly produced hydra gets
separated from its parent hydra and becomes an
independent organism.
14.
15. FRAGMENTATION
• Fragmentation is another mode of asexual
reproduction exhibited by organisms such as
spirogyra.
• The parent body divides into several fragments and
each fragment develops into a new organism.
16. FRAGMENTATION IN SPIROGYRA
• Vegetative reproduction is by fragmentation.
• Under the favourable conditions, vegetative reproduction is the
preferred mode of reproduction.
• The vegetative filament after fragmentation develops into a new
filament.
• Each fragment undergoes multiple division and elongation to
form a new filament
• Fragmentation can be due to mechanical injury or dissolution of
the middle lamella with a change in the salinity and temperature
of the water
17.
18. REGENERATION
• Regeneration is the power of growing a new organism from the
lost body part.
• For eg, when a lizard loses its tail, a new tail grows.
• This is because the specialized cells present in the organism can
differentiate and grow into a new individual.
•
• Organisms like hydra and planaria exhibit regeneration.
19. REGENERATION IN PLANARIA
• Planarian, has specialized stem cells called neoblasts.
• The neoblasts are crucial for the process of regeneration, where missing
tissues are regenerated after an injury.
• Furthermore, neoblasts are the only dividing cells of the adult animal. This is
comparable to pluripotent stem cells in humans
• However, these cells do not remain after birth. Hence, neoblasts in planarians
are the key to regeneration since these are the only type of cells that survive
into adulthood and are capable of division in the adult animal.
20.
21. SPORE FORMATION
• Spore formation is another means of asexual
reproduction.
• During unfavorable conditions, the organism develops
sac-like structures called sporangium that contain
spores.
• When the conditions are favorable, the sporangium
burst opens and spores are released that germinate to
give rise to new organisms
22.
23. ADVANTAGES OF ASEXUAL REPRODUCTION
• Mates not required.
• The process of reproduction is rapid.
• An enormous number of organisms can be produced
in very less time.
• Positive genetic influences pass on to successive
generations.
• It occurs in various environments.
24. DISADVANTAGES OF ASEXUAL REPRODUCTION
• Lack of diversity. Since the offsprings are genetically identical to
the parent they are more susceptible to the same diseases and
nutrient deficiencies as the parent. All the negative mutations
persist for generations.
• Since only one organism is involved, the diversity among the
organisms is limited.
• They are unable to adapt to the changing environment.
• A single change in the environment would eliminate the entire
species.