The document discusses the scientific method, which is a process used to answer questions about the world through experiments and observations. It involves identifying a problem, developing a hypothesis, designing and conducting an experiment, collecting and analyzing data, and drawing conclusions. Key parts of the scientific method include formulating hypotheses, identifying independent, dependent, and controlled variables, developing procedures, and organizing and presenting results. The document provides examples of experiments and identifies the variables involved.
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 pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
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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.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
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.
(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.
2. The Scientific Method
∗What is the scientific
method?
∗It is a process that
is used to find
answers to
questions about
the world around
us.
3. ∗ Is there only one “scientific method”?
∗ No, there are several versions of the
scientific method.
∗ Some versions have more steps, while
others may have only a few.
∗ However, they all begin with the
identification of a problem or a question to
be answered based on observations of the
world around us.
5. ∗ What is a hypothesis?
∗ It is an educated
guess based on
observations and
your knowledge of
the topic.
∗ You state it as a
possible answer to
a question.
6. ∗ Stated in the “If…..,
then….” format
∗ Example: IF I water
three plants with
different sodas,
THEN the plant that
receives Sprite will
grow the tallest.
7. ∗What is data?
∗It is information
gathered during
an experiment.
∗It is organized
into a data table
and displayed
visually as a
graph.
8. Graphs
∗ BAR GRAPHS: can be used to show
how something changes over time
or to compare items.
∗ have an x-axis (horizontal) and a
y-axis (vertical)
∗ the x-axis has time period or
what is being measured
∗ the y-axis has numbers for the
amount of stuff being measured.
∗ good when you're plotting data
that spans many years (or days,
weeks...), has really big changes
from year to year (or day to
day...), or when you are
comparing things.
9. ∗ LINE GRAPHS: can be used to
show how something changes
over time
∗ x-axis has numbers for the
time period
∗ y-axis has numbers for what is
being measured.
∗ can be used when you're
plotting data that has peaks
(ups) and valleys (downs), or
that was collected in a short
time period.
∗ Used for two sets of numerical
data (ex: time and temp)
10. ∗ 1. Choose a problem: State the
problem as a question.
∗ 2. Research your problem: Read, get
advice, and make observations.
∗ 3. Develop a hypothesis: Make a
prediction about what will happen.
∗ 4. Design an experiment: Plan how you
will test your hypothesis.
Steps of the Scientific Method
11. ∗ 5. Test your hypothesis: Conduct the
experiment and record the data.
∗ 6. Organize your data: Create a chart or
graph of your data.
∗ 7. Draw conclusions: Analyze your data
and summarize your findings.
16. ∗Dependent Variable – something that
might be affected by the change in the
independent variable
∗ What is observed
∗ What is measured
∗ The data collected during the investigation
∗ “the numbers”
∗ Example: how tall the plant grew, how far
the paper airplane flew
18. ∗Controlled Variable – a variable that is
not changed
∗Also called CONSTANTS
∗Allow for a “fair test”
∗Everything in the experiment except
for the IV should be kept constant
19. ∗ Give a detailed explanation of how you will
conduct the experiment to test your hypothesis
∗ Be clear about the variables (elements you
change) versus your constants (elements that do
not change)
∗ A control is the group that you use as a
comparison to see if change has occurred.
∗ Example: In a medicine study, the group of
people who don’t get the medicine are the
control group
Procedure
20. ∗ Be very specific about how you
will measure results to prove or
disprove your hypothesis. You
should include a regular timetable
for measuring results or
observing the projects (such as
every hour, every day, every
week)
21. ∗ Conclusion: your results or findings based on
data collected during the experiment
∗ Answer your problem/purpose statement
∗ What does it all add up to? What is the value of
your project?
∗ What further study do you recommend given the
results of your experiment? What would be the
next question to ask?
∗ If you repeat this project, what would you
change?
Conclusion
22. For Example:
Students of different ages were
given a jigsaw puzzle to put
together. The scientist wanted to
see if the students’ ages affected
how long it took to put the puzzle
together.
23. ∗Independent Variable (IV):
∗Ages of the students
∗Different ages were tested by the scientist
∗Dependent Variable (DV):
∗The time it took to put the puzzle
together
∗The time was observed and measured by
the scientist
Identify the Variables in this
Experiment:
24. ∗ (1) Same puzzle
∗ All of the participants were tested with the
same puzzle.
∗ It would not have been a fair test if some
had an easy 30 piece puzzle and some had a
harder 500 piece puzzle.
∗ Other constants: (2) same location, (3) same
stopwatch, (4) same person timing the
experiment
What were the constants?
25. ∗ An investigation was done with an
electromagnetic system made from a battery
and wire wrapped around a nail. Different sizes
of nails were used. The number of paper clips
the electromagnet could pick up was measured.
Another Example:
26. ∗IV: Sizes of nails
∗These were changed by the scientist
∗DV: Number of paper clips picked up
∗The number of paper clips observed and
counted (measured)
∗Constants: Battery, wire, type of nail
∗None of these items were changed
What are the Variables?
27. Let’s Practice!
∗If I use a heavier bowling
ball, then the ball will
travel faster down the
lane.
∗IV: weight of bowling ball
∗DV: speed it traveled
down lane
28. ∗ 2) If I use different brands of
paper towels, then Bounty
will absorb more water per
minute than Sparkle or
Quilted.
∗ IV: brand of paper towel
∗ DV: amount of water
absorbed per minute
29. ∗3) If I put 3 spider plants in
different locations, then the
plant in the sunlight will grow
taller in a one-week period
than the plants in the closet
and basement.
∗IV: location of the plants
∗DV: height of plants