MENDELE'S EXPERIMNENT AND TERMINOLOGY, BY MR. DINABANDHU BARAD, MSC TUTOR, DEPARTMENT OF PEDIATRIC, SUM NURSING COLLEGE, SIKSHA 'O' ANUSANDHAN DEEMED TO BE UNIVERSITY
MENDELE'S EXPERIMNENT AND TERMINOLOGY, BY MR. DINABANDHU BARAD, MSC TUTOR, DEPARTMENT OF PEDIATRIC, SUM NURSING COLLEGE, SIKSHA 'O' ANUSANDHAN DEEMED TO BE UNIVERSITY
Genetics: The study of heredity.
Heredity is the relations between successive generations.
Why do children look a little bit like their parents but also different?What is responsible for these similarities and differences? this slides try to explain why these things are happening.
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.
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 .
(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.
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.
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.
2. What is Mendalian genetics ?
Mendelian inheritance is a type
of biological inheritance that follows the
principles originally proposed by Gregor
Mendel in 1865 and 1866, re-discovered in 1900
and popularised by William Bateson.
3. Gregor Johann Mendel
• Austrian monk.
• Born on 22 July 1822.
• His father was peasant and his
grandfather was gardener.
• Was initially taught by local
priest but later on he was
admitted in an Institute of
Philosophy.
• He was not financially well to
do therefore in 1843, he
terminated his studies and went
back to monastery in Brunn.
• He was made incharge of
garden at the monastery and
named himself Gregor.
4. Gregor Johann Mendel
• He became priest in 1847
• After 4 years he went to
University of Vienna
where he studied physics,
mathematics , chemistry
and botany.
• When he returned to
monastery after completing
his studies , he took the
position as a teacher of
natural sciences at the
Technical School.
5. Why Mendel chose peas ?
• Mendel first started with mice. He
thought he would take mice with
different characters and make them
mate , look at their offsprings and
see if some pattern is there.
• He did the same thing in honeybees.
• Both experiments didn’t work out.
• The problem is you can’t control
when animals mate, right?
• Eventually Mendel turned towards
garden peas.
• He found peas were perfect for his
experiment.
6. Why Mendel chose peas ?
• Why peas exactly ?
• First it’s a plant he could control
mating/ fertilization.
• Peas have very short life cycle.
Only take 3 months to grow to full
height. Apple tree take 10 years so
apple tree would be the worst
candidate if you want to do a lot of
experiments.
• Pea plant have a lot of observable
contrasting characters to
experiments. Characters had only 2
contrasting traits.
11. Terminology
• GENE:Gene is the shortest segment of DNA responsible for
the expression of its specific character.
• Gene is also called as the basic unit of heredity. It is small
DNA segment that determines a biological character of an
organism. Gene is situated on chromosomes.
• GENOME:It is the total genetic composition of an organism.
• ALLELE:Allele is an alternate form of the same gene in
which one is parental and other is maternal. In case of plant
height, tallness and dwarfness are the two alleles of a gene.
12. • DOMINANT ALLELE:Out of two alleles, the one that is
capable of expressing itself by hiding or suppressing its
contrasting allele is known as dominant allele.
• RECESSIVE ALLELE:Out of two alleles, the one that is being
suppressed by its alternative allele is called as recessive
allele.
• Recessive is an allele that does not express itself when
present with the dominant allele (in heterozygous form).
• HOMOZYGOUS:A diploid individual carrying two identical
alleles is known as homozygous.
• It is pure for a trait or character.
13. • HETEROZYGOUS:A diploid individual carrying two different
alleles is known as heterozygous or hybrid.
• It is impure for a trait (T t)
• GENOTYPE:A genotype is a genetic expression of an
organism.
• For plant height, TT, Tt and tt are the different genotype
• PHENOTYPE:It is the physical or the observable expression
of an organism.
• It is the observable characteristic of an individual.
14. • CHARACTER:It refers to a general feature of an
organism such as eye color, plant height etc.
• HYBRID:The product of a cross between two
genetically different individual belonging to the same
genus or species or between two different genera is
called hybrid.
• MONOHYBRID CROSS:A cross between the two
parents that are differing in one pair of alternating
(contrasting) character is called monohybrid cross.
• In this type, single character is used.
15. • DIHYBRID CROSS:A cross between the two parents that are
differing in two pairs of alternating character is called
dihybrid cross.
• In this type, two contrasting characters are used. For
example, seed shape and seed color (round yellow versus
wrinkled green)
• FILAL GENERATION:The progeny obtained as a result of
crossing between parents is a hybrid progeny and is called
First filial generation, represented by F1 (filial=offsprings).
• The progeny obtained as a result of self-fertilization among
F1 plants represents second filial generation represented as
F2.
18. Law of segregation
Law of segregation states
that allele pairs separate or
segregate during gamete
formation and randomly
unite at fertilization.
19.
20. Law of Independent Assortment
• Mendel's law of independent
assortment states that the alleles of two (or
more) different genes get sorted into gametes
independently of one another. In other words,
the allele a gamete receives for one gene does
not influence the allele received for another
gene