1) The sperm and egg undergo a series of changes to prepare for fertilization. The sperm undergoes capacitation in the female reproductive tract while the egg is swept into the fallopian tubes.
2) Upon contact, the acrosomal reaction occurs, releasing enzymes that allow the sperm to penetrate the egg's extracellular layers.
3) One sperm fuses with the egg, and their pronuclei also fuse to form a single diploid cell with 46 chromosomes. Rapid changes then prevent additional sperm from fertilizing the egg.
This topic contains Gametogenesis- oogenesis and spermatogenesis, ovulation, fertilization, development of fertilized ovum/ zygote, implantation, development of decidua, chorion and chorionic villi, development of inner cell mass.
Anomalies of the first and second branchial archesDr Medical
https://userupload.net/8n9v7tg9jkl1
Anomalies of the branchial arches are the second most common congenital lesions of the head and neck in children [1]. They may present as cysts, sinus tracts, fistulae or cartilaginous remnants and present with typical clinical and radiological patterns dependent on which arch is involved. The course of a particular branchial anomaly is caudal to the structures derived from the corresponding arch and dorsal to the structures that develop from the following arch. Branchial anomalies are further typed into cysts, sinuses, and fistulas.
USMLE GENERAL EMBRYOLOGY 008 First week of development A embryo .pdfAHMED ASHOUR
The initial week of embryonic development is a vital period commencing with fertilization, leading to the creation of the zygote and early cell divisions. It's noteworthy that, throughout this week, the developing embryo remains in the pre-implantation stage, journeying from the fallopian tube toward the uterus. Key events such as fertilization, cleavage, and the formation of the blastocyst are crucial for the embryo's early development.
These events lay the foundation for subsequent processes in the following weeks. The successful implantation of the blastocyst into the uterus marks the transition from the first week to the second week of embryonic development.
This topic contains Gametogenesis- oogenesis and spermatogenesis, ovulation, fertilization, development of fertilized ovum/ zygote, implantation, development of decidua, chorion and chorionic villi, development of inner cell mass.
Anomalies of the first and second branchial archesDr Medical
https://userupload.net/8n9v7tg9jkl1
Anomalies of the branchial arches are the second most common congenital lesions of the head and neck in children [1]. They may present as cysts, sinus tracts, fistulae or cartilaginous remnants and present with typical clinical and radiological patterns dependent on which arch is involved. The course of a particular branchial anomaly is caudal to the structures derived from the corresponding arch and dorsal to the structures that develop from the following arch. Branchial anomalies are further typed into cysts, sinuses, and fistulas.
USMLE GENERAL EMBRYOLOGY 008 First week of development A embryo .pdfAHMED ASHOUR
The initial week of embryonic development is a vital period commencing with fertilization, leading to the creation of the zygote and early cell divisions. It's noteworthy that, throughout this week, the developing embryo remains in the pre-implantation stage, journeying from the fallopian tube toward the uterus. Key events such as fertilization, cleavage, and the formation of the blastocyst are crucial for the embryo's early development.
These events lay the foundation for subsequent processes in the following weeks. The successful implantation of the blastocyst into the uterus marks the transition from the first week to the second week of embryonic development.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
6. Ovum and sperms: (In vitro)
The surfaces of unfertilized eggs are usually smooth in appearance. The mottled look
of this egg is not normally seen, but apparently all the ova from this woman had this
appearance.
From this photograph, it
should be clear that the
heads of human sperm
are less than 1/20 the
diameter of human eggs.
sperm heads
8. Pre- fertilization events
Helping the sperm:
At ovulation, the cervical mucus increases in amount
and becomes less thick, allowing easier sperm
transport.
Passage of the sperm through the uterus and oviduct
occurs mainly due to muscular contractions of these
organs.
Oocyte:
The ends of the oviducts come into close contact
with the ovary during ovulation.
Fimbriae of oviduct ends “sweep” the ovulated ovum
into the oviduct.
Peristaltic waves of oviduct musculature bring the
ovum into the ampulla of the oviduct.
9. Capacitation: readying the sperm
Sperms cannot fertilize oocytes when they
are newly ejaculated.
The process of capacitation takes 5-7 hours.
Capacitated sperms are more active.
Location: capacitation occurs in the uterus
and oviducts and is facilitated by substances
of the female genital tract.
The acrosomal reaction cannot occur until
capacitation has occurred.
10. Process of Fertilization
(1) Chemo attraction
(2) Release of acrosomal enzymes
(3) Binding of sperm to extra cellular envelopes
(4) Passage through extra cellular envelopes
(5) Fusion of sperm and egg pronuclei
11. (1) Chemo attraction
Species specific in many invertebrates, In sea
urchin a peptide resact is such chemo tactic
molecule. It is also sperm activating molecule.
Egg jelly has other compounds as well, which
bind with specific receptors on sperm, which
inturn opens calcium ion channels, leading to
exocytosis of acrosome.
12. (2) Release of acrosomal enzymes
In mammals, zona pellucida ZP-3 glycoprotein
which triggers Acrosomal reaction.
Prerequisite for the fusion of nuclei. Steps are:
14. (3) Binding of sperm to extra cellular envelopes
Passage of sperm through the corona radiata depends
on enzyme action:
Flagella action also aids corona radiata penetration.
Penetration of the zona pellucida around the oocyte:
Once sperm penetrates zona pellucida, the zona
reaction occurs:
This reaction makes the zona pellucida impermeable to
other sperms.
When more than one sperm manages to enter the ovum
(dispermy = 2; triploidy = 3), the fetus nearly always
15. Prevention of polyspermy
In mammals, prevention of polyspermy is
mainly achieved by:
Changing of the electric potential of egg
membrane by pumping high amount of Na+
outside the egg surface-
The cortical reaction occurs in fertilisation when a
sperm cell unites with the egg's plasma
membrane, (zona reaction).This reaction leads to
a modification of the zona pellucida that blocks
polyspermy-
18. (4) Passage through extra cellular envelopes
Head and tail of a sperm enter the cytoplasm
of the oocyte, but the sperm plasma
membrane remains behind.
The secondary oocyte was previously
arrested in metaphase of the 2nd meiotic
division, and now forms the mature ovum
19. (5) Fusion of sperm and egg pronuclei
Formation of male and female pronuclei:
Chromosomal material of the sperm
decondensates and enlarges
Chromosomal material of the ovum
decondensates following the completion of
meiosis
At this stage, the male and female
pronuclei are indistinguishable.
As they grow, the pronuclei replicate their
DNA still 1N (haploid)- 23
chromosomes, each in chromatid pairs
20. The male and female
pronuclei are
indistinguishable from one
another.
The second polar body can
be seen (arrow).
The plasma membranes of
the two pronuclei are
dissolving and one diploid
nucleus will remain.
Fusion of the pronuclei:
21. Cont.
Membranes of the pronuclei break down,
chromosomes condense and arrange
themselves for mitotic cell division
On membrane dissolution, there is 1 cell with
46 chromosomes = diploid (2N)
The first cleavage follows shortly, leaving 2
cells, each with 46 chromosomes.
Mitosis in the new zygote uses centrioles derived
from the sperm. The oocyte has no centrioles.
22. Fertilization facts:
Completed within 24 hours of ovulation
Approximately 400 to 600 MILLION sperms are
deposited at cervical opening during ejaculation.
Some sperm are held up by the folds of the cervix and
are gradually released into the cervical canal; this gradual
release increases the chances of fertilization.
Most human sperms do not survive longer than 48 hours
in the female genital tract.
Only about 200 sperms reach the fertilization site;
most degenerate and are absorbed by the female
genital tract.
23. The results of fertilization:
Stimulates the secondary oocyte to complete
meiosis.
Restores the normal diploid number of
chromosomes (46).
Results in variation of human species as
maternal and paternal chromosomes
intermingle.
The embryo contains only maternal
mitochondria because the sperm mitochondria
are dispersed into the egg cytoplasm and
discarded.
Determines the sex of the embryo.