The respiratory system consists of organs and structures used for respiration. In mammals, respiration occurs through pulmonary ventilation via the nasal cavity, lungs, and diaphragm. The lungs exchange gases through alveoli and are protected by the rib cage. Horses and marine mammals have respiratory adaptations like nasal breathing and mechanisms to prevent water inhalation during dives.
Why do animals need to breathe?
Breathing is important to organisms because cells require energy (oxygen) to move, reproduce and function. Breath also expels carbon dioxide, which is a by-product of cellular processes within the bodies of animals.
Respiration is the process of releasing energy from food and this takes place inside the cells of the body.
The process of respiration involves taking in oxygen (of air) into cells, using it for releasing energy by burning food, and then eliminating the waste products (carbon dioxide and water) from the body.
Respiration is essential for life because it provides energy for carrying out all the life processes which are necessary to keep the organisms alive.
The energy produced during respiration is stored in the form of ATP (Adenosine Tri- Phosphate) molecules in the cells of the body and used by the organism as when required.
KEY POINTS
Life started in an anaerobic environment in the so called ‘primodial broth’ (a mixture of organic molecules.
Subsequently, oxygen strangely enough became an crucial factor for aerobic metabolism especially in the higher life forms.
The rise of an oxygenic environment was an important event in the diversification of life.
It evoked a dramatic shift from inefficient to sophisticated oxygen dependent oxidizing ecosystems.
Anaerobic fermentation, the metabolic process that prevailed for the first about 2 billion years of the evolution of life, was a very inefficient way of extracting energy from organic molecules. Ex: A molecule of glucose, e.g., produces only two molecules of ATP (≈ 15 kCal) compared with 36 ATP molecules (≈ 263 kCal) in oxygenic respiration.
Aerobic metabolism must have developed at a critical point when the partial pressure of oxygen rose from an initial level to one adequately high to drive it passively across the cell membrane.
Respiration is a complex and highly integrated biomechanical, physiological, and behavioral processes.
The transfer of O2 occurs through a flow of tissue barriers and compartments by diffusion down a partial pressure gradient, which drops to about zero at the mitochondrial level.
Acquisition of molecular oxygen (O2) from the external fluid media (water and air) and the discharge of carbon dioxide (CO2) into the same milieu is the primary role of respiration.
The respiratory system is a biological system consisting of specific organs and structures.
Specialities in Birds respiratory system: Air sacs, specialized parabronchi , Unidirectional flow
Benifits of air sacs, Benefit of 2 respiratory cycles
Bird-like respiratory systems in dinosaurs
Rate of breathings in birds
Air sacs are thin walled non-muscular,non-vascular,non-elastic and bladder like membrane connected to the lungs
Air sacs are only the inflated extensions of the mucous membrane of some blindly ending bronchioles
Some of them extended to bones
In pigeon there are nine major air sacs
One of them is unpaired and others are paired
Unpaired air sac is interclavicular
Paired sac include cervical,anterior thoracic,posterior thoracic and abdominal air sacs
Abdominal and posterior thoracic sacs get filled with fresh air during inspiration.so they are called inspiratory air sacs
Others get filled with fresh air during expiration
Why do animals need to breathe?
Breathing is important to organisms because cells require energy (oxygen) to move, reproduce and function. Breath also expels carbon dioxide, which is a by-product of cellular processes within the bodies of animals.
Respiration is the process of releasing energy from food and this takes place inside the cells of the body.
The process of respiration involves taking in oxygen (of air) into cells, using it for releasing energy by burning food, and then eliminating the waste products (carbon dioxide and water) from the body.
Respiration is essential for life because it provides energy for carrying out all the life processes which are necessary to keep the organisms alive.
The energy produced during respiration is stored in the form of ATP (Adenosine Tri- Phosphate) molecules in the cells of the body and used by the organism as when required.
KEY POINTS
Life started in an anaerobic environment in the so called ‘primodial broth’ (a mixture of organic molecules.
Subsequently, oxygen strangely enough became an crucial factor for aerobic metabolism especially in the higher life forms.
The rise of an oxygenic environment was an important event in the diversification of life.
It evoked a dramatic shift from inefficient to sophisticated oxygen dependent oxidizing ecosystems.
Anaerobic fermentation, the metabolic process that prevailed for the first about 2 billion years of the evolution of life, was a very inefficient way of extracting energy from organic molecules. Ex: A molecule of glucose, e.g., produces only two molecules of ATP (≈ 15 kCal) compared with 36 ATP molecules (≈ 263 kCal) in oxygenic respiration.
Aerobic metabolism must have developed at a critical point when the partial pressure of oxygen rose from an initial level to one adequately high to drive it passively across the cell membrane.
Respiration is a complex and highly integrated biomechanical, physiological, and behavioral processes.
The transfer of O2 occurs through a flow of tissue barriers and compartments by diffusion down a partial pressure gradient, which drops to about zero at the mitochondrial level.
Acquisition of molecular oxygen (O2) from the external fluid media (water and air) and the discharge of carbon dioxide (CO2) into the same milieu is the primary role of respiration.
The respiratory system is a biological system consisting of specific organs and structures.
Specialities in Birds respiratory system: Air sacs, specialized parabronchi , Unidirectional flow
Benifits of air sacs, Benefit of 2 respiratory cycles
Bird-like respiratory systems in dinosaurs
Rate of breathings in birds
Air sacs are thin walled non-muscular,non-vascular,non-elastic and bladder like membrane connected to the lungs
Air sacs are only the inflated extensions of the mucous membrane of some blindly ending bronchioles
Some of them extended to bones
In pigeon there are nine major air sacs
One of them is unpaired and others are paired
Unpaired air sac is interclavicular
Paired sac include cervical,anterior thoracic,posterior thoracic and abdominal air sacs
Abdominal and posterior thoracic sacs get filled with fresh air during inspiration.so they are called inspiratory air sacs
Others get filled with fresh air during expiration
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
The primitive blueprint for the heart and circulatory system emerged with the arrival of the third mesodermal germ layer in bilaterians. Since then, hearts in animals have evolved from a single layered tube to a multiple chambered heart in due course of time.
Evolutionary change in heart of vertebrates
Heart is situated ventral to the oseophagus in the pericardial section of the coelom.
Heart is a highly muscular pumping organ that pumps blood into arteries and sucks it back through the veins.
In vertebrates it has undergone transformation by twisting from a straight tube to a complex multi-chambered organ.
. There has been an increase in the number of chambers in heart during evolution of vertebrates.
The heart is covered by a transparent protective covering, called pericardium. It is a single layer in fish.
Within pericardium there is a pericardial fluid, protects the heart from the external injury.
The evolution of the heart is based on the separation of oxygenated blood from deoxygenated blood for efficient oxygen transport.
Birds require large amount of oxygen due to their flight activity in accordance to which their respiratory system is comparatively more complex and developed.
In primitive vertebrates, such as the lancelet (petromyzon), the circulating fluid moves without a heart as the central organ of circulation.
In fishes’ single-circuit system, the gills and the heart are placed in series. The two-chambered heart supplies the blood to gills with pressures that exceed those in the arteries. Largely devoid of gravity, fish depend on water for respiration, fluid balance, thermoregulation, reproduction, and fin development.
The amphibians are adapted to life in water only during early stages of their development. Transition to land is marked by loss of fins and gills, and the emergence of tail and limbs.
Adaptation to air respiration introduces a fundamental change in the structure of the cardiovascular system. The heart and the lung are joined by a newly formed pulmonary circulation placed in parallel with the systemic circulation. In contrast to fish, the circulatory loops cross and assume the shape of a lemniscate (figure-eight or ∞-shaped curves).
The heart acquires a new chamber, the left atrium, while a common ventricle is shared between the pulmonary and systemic loops. Amphibians continue to depend for temperature, reproduction, and part of their respiratory needs on water (skin respiration).
Through the development of complicated organ systems such as thermoregulation, respiration, excretion, inner reproduction, and locomotion, mammals have attained a high degree of environmental liberation.
The cardiovascular system consists of two anatomically separate, but functionally unified, parts—the systemic and pulmonary circulations—placed in series.
In addition to an independent inner watery environment, mammals have developed an “inner atmosphere,” reflected primarily in the partial pressure of oxygen and nitrogen in the blood that parallels the atmospheric pressure.
The essential new feature of the mammalian circulation is a pressurized arterial compartment. The similarity of arterial pressure across the mammalian species suggests that the pressure as such does not serve the blood propulsion.
Vertebrate Circulatory Systems:
transport gases, nutrients, waste products, hormones, heat, & various other materials
consist of heart, arteries, capillaries, & veins:
Arteries
carry blood away from the heart
have muscular, elastic walls
terminate in capillary beds
Capillaries
have very thin walls (endothelium only)
are the site of exchange between the blood and body cells
Veins
carry blood back to the heart
have less muscle in their walls than arteries but the walls are very elastic
begin at the end of capillary beds
Heart
a muscular pump (cardiac muscle)
contains a pacemaker to regulate rate but rate can also be influenced by the Autonomic Nervous System
Presentation on Organ & Mechanism of Respiration in Pisces And Amphibiansvskgondia
This is Powerpoint presentation helpful for students and teachers. It includes Defination of Respiration & Function of respiratory system. Also contains mechanism of respiration and various repiratory organs of pisces and amphibians, their structures and fuctions.
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
The primitive blueprint for the heart and circulatory system emerged with the arrival of the third mesodermal germ layer in bilaterians. Since then, hearts in animals have evolved from a single layered tube to a multiple chambered heart in due course of time.
Evolutionary change in heart of vertebrates
Heart is situated ventral to the oseophagus in the pericardial section of the coelom.
Heart is a highly muscular pumping organ that pumps blood into arteries and sucks it back through the veins.
In vertebrates it has undergone transformation by twisting from a straight tube to a complex multi-chambered organ.
. There has been an increase in the number of chambers in heart during evolution of vertebrates.
The heart is covered by a transparent protective covering, called pericardium. It is a single layer in fish.
Within pericardium there is a pericardial fluid, protects the heart from the external injury.
The evolution of the heart is based on the separation of oxygenated blood from deoxygenated blood for efficient oxygen transport.
Birds require large amount of oxygen due to their flight activity in accordance to which their respiratory system is comparatively more complex and developed.
In primitive vertebrates, such as the lancelet (petromyzon), the circulating fluid moves without a heart as the central organ of circulation.
In fishes’ single-circuit system, the gills and the heart are placed in series. The two-chambered heart supplies the blood to gills with pressures that exceed those in the arteries. Largely devoid of gravity, fish depend on water for respiration, fluid balance, thermoregulation, reproduction, and fin development.
The amphibians are adapted to life in water only during early stages of their development. Transition to land is marked by loss of fins and gills, and the emergence of tail and limbs.
Adaptation to air respiration introduces a fundamental change in the structure of the cardiovascular system. The heart and the lung are joined by a newly formed pulmonary circulation placed in parallel with the systemic circulation. In contrast to fish, the circulatory loops cross and assume the shape of a lemniscate (figure-eight or ∞-shaped curves).
The heart acquires a new chamber, the left atrium, while a common ventricle is shared between the pulmonary and systemic loops. Amphibians continue to depend for temperature, reproduction, and part of their respiratory needs on water (skin respiration).
Through the development of complicated organ systems such as thermoregulation, respiration, excretion, inner reproduction, and locomotion, mammals have attained a high degree of environmental liberation.
The cardiovascular system consists of two anatomically separate, but functionally unified, parts—the systemic and pulmonary circulations—placed in series.
In addition to an independent inner watery environment, mammals have developed an “inner atmosphere,” reflected primarily in the partial pressure of oxygen and nitrogen in the blood that parallels the atmospheric pressure.
The essential new feature of the mammalian circulation is a pressurized arterial compartment. The similarity of arterial pressure across the mammalian species suggests that the pressure as such does not serve the blood propulsion.
Vertebrate Circulatory Systems:
transport gases, nutrients, waste products, hormones, heat, & various other materials
consist of heart, arteries, capillaries, & veins:
Arteries
carry blood away from the heart
have muscular, elastic walls
terminate in capillary beds
Capillaries
have very thin walls (endothelium only)
are the site of exchange between the blood and body cells
Veins
carry blood back to the heart
have less muscle in their walls than arteries but the walls are very elastic
begin at the end of capillary beds
Heart
a muscular pump (cardiac muscle)
contains a pacemaker to regulate rate but rate can also be influenced by the Autonomic Nervous System
Presentation on Organ & Mechanism of Respiration in Pisces And Amphibiansvskgondia
This is Powerpoint presentation helpful for students and teachers. It includes Defination of Respiration & Function of respiratory system. Also contains mechanism of respiration and various repiratory organs of pisces and amphibians, their structures and fuctions.
Accssory respiratiory organs in fishesaadiihussain
Gills are primary respiratory organs in fishes, Extra branchial respiration is highly useful for survival when oxygen supplied by gills is not sufficient.
Physiology of Respiration in InvertebratesPRANJAL SHARMA
In physiology, respiration is the movement of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction. In these slides you will get to know about Physiology of Respiration in Invertibrates.
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.
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.
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.
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.
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.
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 .
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.
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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
2. It is a biological system consisting of specific organs
and structures used for the process of respiration in
an organism
WHAT IS RESPIRATORY SYSTEM?
3. Gas exchange: Oxygen enters blood and carbon
dioxide leaves
Regulation of blood pH: Altered by changing blood
carbon dioxide levels
Voice production: Movement of air past vocal folds
makes sound and speech.
Olfaction: Smell occurs when airborne molecules are
drawn into nasal cavity.
Protection: Against microorganisms by preventing
entry and removing them from respiratory surfaces.
RESPIRATORY SYSTEM FUNCTIONS
5. Respiratory system does this through breathing.
When we breathe, we inhale oxygen and exhale
carbon dioxide. This exchange of gases is the
respiratory system’s means of getting oxygen to the
blood.
HOW DOES IT WORK?
6. Endoderm forms the respiratory system, having a
sheet of approximately 500-1000 cells.
Phases of Lung Development- growth and
transcription factors.
EMBRYONIC ORIGIN
7. Mechanism of respiration
Chordates have one of two basic structures for
respiration:
Gills – for aquatic chordates
Example: tunicates, fish and amphibians
Lungs - for terrestrial chordates
Examples: adult amphibians, reptiles, birds, and mammals
8. 1.) Aquatic Gills
Water flows
through the mouth
then over the gills
where oxygen is
removed
Carbon dioxide
and water are then
pumped out
through the
operculum
9. Increase the surface area
Containing blood vessels covered by a thin epithelial
layer
Organized into a series of plates
Countercurrent principle
Maybe:
internal (as in crabs and fish) or
external to the body (as in some amphibians).
10. 2. ) Vertebrate lungs
As you move from amphibians to mammals the
surface area of the lungs increases
Insures a greater amount of gas exchange (or a two way
flow of air).
Birds, by contrast have lungs and air sacs which
have only a one-way flow of air.
This allows for them to have constant contact with fresh
air.
This adaptation enables them to fly at high altitudes
where there is less oxygen.
11. Section 33-3
Salamander Lizard PigeonPrimate
Nostrils, mouth, and
throat
Trachea
Lung
Air sac
Figure 33–10: Vertebrate Lungs
12. Although…
o Skin
- Examples:
Amphibians, Humans (also)
-ancestral form of respiration
-sometimes used External cutaneous respiration
-Use their outer surfaces
-Gas exchange occurs at capillaries located
throughout the body
13. Section 37-3
Flowchart
Oxygen and
carbon dioxide
exchange at
alveoli
Oxygen-rich
air from
environment
Bronchioles
Nasal
cavities
Pharynx Trachea Bronchi
BronchiolesAlveoli
Pharynx
Nasal
cavities
Carbon
dioxide-rich
air to the
environment
Bronchi
Trachea
Movement of Oxygen and Carbon Dioxide In and
Out of the Respiratory System
BIG
QUESTION
…
WHY DO ANIMALS BREATHE?
15. Gills
mediate gas exchange
located at the side of the head
made up of gill filaments , feather structures that provide a
large surface for gas exchange
Adult fishes have a pair of gills. Each gills is covered
by a bony lid. A fish draws in water by closing the lid over
its gills and opening its mouth. When the fish closes its
mouth and opens the gill lid, the water is forced out and
over the respiratory surfaces of the gill filaments.
16. Gill Structure
Gill filaments – the site of gas exchange
(Each gill filament consists of an upper and lower surface
covered with minute ridges known as lamellae.)
Gill rakers – appendages along the front edge of the gill
arch
Gill arches – support the gills
Swim bladder – gas filled chamber that allow the bony fish
to remain floating in the water
17.
18. Bony fishes
Water enters the gill chamber through the fish’s mouth and
exits through gill openings under the operculum. Blood
flowing through the gill filaments absorbs oxygen from the
water.
Some species of bony fishes can absorb considerable
amounts of oxygen through their skin.
19. Bony fishes
Usually have 5 gill slits
Operculum projects backward over gill chambers
Interbranchial septa are very short or absent
Lamellae are made of extremely thin membranes (1 cell
thick) and are primary sites of gas exchange.
Water flows across the gill filaments and oxygen is
removed and passes into the blood by diffusion.
To increase the efficiency of oxygen uptake a
countercurrent method is used; blood flows through the
lamellae in a direction opposite to the water flow through
the gill filaments. Countercurrent flow ensures a steady
oxygen.
21. The anatomical structure of the lungs is less
complex in reptiles than in mammals, with
reptiles lacking the very extensive airway
tree structure found in mammalian lungs. Gas
exchange in reptiles still occurs
in alveoli however, reptiles do not possess
a diaphragm.
Thus, breathing occurs via a change in the
volume of the body cavity which is
controlled by contraction of intercostal
muscles in all reptiles except turtles. In
turtles, contraction of specific pairs of flank
muscles governs inspiration or expiration.
22. To survive on land, the reptiles had to develop a skin relatively impermeable to water, so as
to prevent desiccation, and hence not well suited for respiration. The most complex
reptilian lungs are found in sea turtles such as Chelonia mydas, the green turtle.
Crocodiles and alligators have a specialized muscle attached to the posterior surface of
the liver; the anterior surface of the liver in turn is attached to the posterior surface of
the lungs
The adoption of a rigid shell by turtles and tortoises necessitated the development of
highly specialized skeletal muscles to inflate the lungs. In the tortoise Testudo graeca,
lung ventilation is achieved by changing the volume of the body cavity.
The breathing patterns of most reptiles are not regular, usually consisting of a series of
active inspirations and expirations followed by relatively long pauses. The metabolic rate
of most reptiles is one-fifth to one-tenth that of birds or mammals, and constant lung
ventilation is unnecessary in most reptiles.
24. PARTS and FUNCTIONS
Larynx – also known as “voice box”. This is supported by the hyoid cartilage
HYOID CARTILAGE – a flat body covered by the muscles at the floor of the
buccal cavity.
Arytenoids – a pair of valve like cartilage forming the dorsal roof of pharynx
and sides of glottis
Lungs – a pair of thin-walled sacs located at the antero-lateral region of the
pleuroperitoneal cavity.
Cricoid – a ring like cartilage surrounding the arytenoids.
Vocal cords – the sound producing apparatus inside the larynx
Alveoli – found at the inner wall of the lungs which divides the lungs into
small chambers.
Pleural membrane – shiny thin membrane that covers the outer surfaces of
the lungs.
Glottis – opening of the larynx.
25. Unlike birds and mammals, amphibians are cold
blooded.
They do not use up any energy for keeping their
bodies at a constant temperature.
26. PULMONARY RESPIRATION
Respiration through lungs is called PULMONARY
RESPIRATION.
This respiration occurs only when the need of Oxygen
is more during swimming and jumping
Alveoli are present. Air enters into the alveoli through
the external and internal nares, buccopharyngeal
cavity, glottis, laryngotrachial chamber, and bronchi.
27. DIFFERENCE BETWEEN AMPHIBIAN
LUNGS AND HUMAN LUNGS
HUMAN
LUNGS
AMPHIBIAN
LUNGS
MORE ALVEOLI
Alveoli increases the amount of surface
that oxygen can enter our bodies
through.
LESS ALVEOLI
Since amphibians don’t need much
oxygen as humans, they have less
alveoli.
HAS A DIAPHRAGM
It causes the air to rush in and out of the
lungs.
NO DIAPHRAGM
They have to force air into their lungs by
moving their mouth as we do while
swallowing.
28. CUTANEOUS RESPIRATION
Respiration through the skin is called CUTANEOUS
RESPIRATION.
It occurs in hibernation and in water
The skin of amphibians are very thin and is rich with
blood capillaries.
The water carries oxygen which diffuses into the
capillaries and the carbon dioxide in the blood
diffuses out.
30. Parts:
• Larynx – is not used to make sound
• Syrinx – serve as voice box
• Lungs
• Air Sacs - Depending upon the
species, the bird has seven or nine
air sacs.
31. The air sacs include:
Two posterior thoracic
Two abdominal
Two anterior thoracic
Two cervical (these are not
present in some species)
One interclavicular
32. The air sacs of birds extend into the humerus (the bone
between the shoulder and elbow), the femur (the thigh
bone), the vertebrae and even the skull.
33. The gas volume of the bird lung <
gas volume of the mammal lung.
Lung is connected to
voluminous air sacs by a series of
tubes, making the total volume of
the respiratory system about twice
that of mammals of comparable
size.
34. Mechanism
Birds do not have a diaphragm.
air is moved in and out of the
respiratory system through pressure
changes in the air sacs.
Aspiration into the air sacs is
produced by expansion of the chest
and abdominal cavity.
Expiration is caused by compression
of the air sacs by skeletal muscle, this
causes the sternum to be pushed
outward.
35. The lungs of birds do not inflate and
deflate but rather retain a constant
volume.
exchange of oxygen and carbon
dioxide occurs in microscopic sacs in
the lungs, called 'alveoli.' In the avian
lung, the gas exchange occurs in the
walls of microscopic tubules, called
'air capillaries.'
36. The air sacs permit a unidirectional flow of air
through the lungs.
Unidirectional flow means that air moving
through bird lungs is largely 'fresh' air & has a
higher oxygen content. In contrast, air flow is
'bidirectional' in mammals, moving back and
forth into and out of the lungs.
As a result, air coming into a mammal's lungs
is mixed with 'old' air & this 'mixed air' has
less oxygen. So, in bird lungs, more oxygen is
available to diffuse into the blood
37.
38. Respiratory cycle of a bird
The air does not go directly to the lung, but
instead travels to the caudal (posterior) air
sacs. A small amount of air will pass
through the caudal air sacs to the lung.
39. the air is moved from the posterior air
sacs through the ventrobronchi and
dorsobronchi into the lungs. The bronchi
continue to divide into smaller diameter
air capillaries. Blood capillaries flow
through the air capillaries and this is
where the oxygen and carbon dioxide
are exchanged.
40. When the bird inspires the second time, the air
moves to the cranial air sacs.
On the second expiration, the air moves out of
the cranial air sacs, through the syrinx into the
trachea, through the larynx, and finally through
the nasal cavity and out of the nostrils.
41. Bird-like respiratory systems in dinosaurs -- A recent
analysis showing the presence of a very bird-like
pulmonary, or lung, system in predatory dinosaurs
provides more evidence of an evolutionary link
between dinosaurs and birds.
44. The mammalian respiratory system equilibrates air to the body,
protects against foreign materials, and allows for gas exchange.
In mammals, pulmonary ventilation occurs via inhalation
when air enters the body through the nasal cavity.
The chief organ in mammalian
respiration is the lungs.
Inhalation happens when the rib cage opens up and the diaphragm
flattens and moves downward. The lungs can then expand into the
larger space that causes the air pressure inside them to decrease,
and the drop in air pressure inside the lung makes the outside air
rush inside.
Exhalation is the opposite process. The diaphragm and the rib
muscles relax to their neutral state that causes the lungs to
contract. The squashing of the lungs increases their air pressure
and forces the air to flow out.
45.
46. Horses are obligate nasal breathers, which means that they
must breathe through their noses.
It is thought that this modification allows horses
to graze with their heads down while separate
nasal passages breath in air and sniff for
potential predators.
Marine mammals breathe oxygen with lungs just like their terrestrial
brethren, but with a few differences. First of all, to prevent water from
getting into their airway they have adapted muscles or cartilaginous
flaps to seal their tracheas when under the water. Additionally, they
exchange up to 90% of their gases in a single breath, which helps them
gather as much oxygen as possible.
Lastly, it can be dangerous for diving
mammals to have air in their lungs when
they dive to great depths.