The significance of the Zygote Phase of Reproduction


Embryology | Fertilization, Cleavage, Blastulation

Video taken from the channel: Ninja Nerd Lectures


Meiosis, Gametes, and the Human Life Cycle

Video taken from the channel: Professor Dave Explains


The process of fertilization and the formation of human.flv

Video taken from the channel: Hà Khả Sơn


Development of Zygote

Video taken from the channel: Creative Learning


Early embryogenesis Cleavage, blastulation, gastrulation, and neurulation | MCAT | Khan Academy

Video taken from the channel: khanacademymedicine


Reproductive System, Part 4 Pregnancy & Development: Crash Course A&P #43

Video taken from the channel: CrashCourse


Development of Embryo | Reproduction in Animals | Don’t Memorise

Video taken from the channel: Don’t Memorise

The zygote is endowed with genes from two parents, and thus it is diploid (carrying two sets of chromosomes). The joining of haploid gametes to produce a diploid zygote is a common feature in the sexual reproduction of all organisms except bacteria. A fertilized egg is called a zygote until it divides into 16 cells, forming a ball-shaped structure called a morula. The events during the zygote stage involve the integration of both parents’ DNA into the cell nucleus and the beginning of rapid cell division, or cleavage. In sexual reproduction zygote is formed by gametes produces by a male and a female. A male and a female gamete fuse to form a zygote which fertilizes to produce new offspring.

Because of the contribution of two parents, off-springs incur more variations. 21. Reproduction is essential for living organisms in order to.

A zygotic meiosis is a meiosis of a zygote immediately after karyogamy, which is the fusion of two cell nuclei. This way, the organism ends its diploid phase and produces several haploid cells. These cells divide mitotically to form either larger, multicellular individuals, or more haploid cells. Two opposite types of gametes (e.g., male and female) from these individuals or cells fuse to become a zygote.

In animals, sexual reproductionencompasses the fusion of two distinct gametes(sex cells) to form a zygote. Gametes are produced by a type of cell division called meiosis. In humans, gametes are produced in the male and female gonads. When gametes unite in fertilization, a new individual is formed.

A zygote will develop into an during the early stages a zygote will develop into. an embryo during the early stages. some cells of the body like neurons and brain cells to not. reproduce themselves. haplontic life. Gametogenesis in males is called spermatogenesis, whereas in females it is oogenesis, both of whose outcomes are different, i.e., sperm and an ovum respectively. The formation of the zygote is followed by the development of the blastocyst, which passes through different stages of development before childbirth.

Start studying Chapter 9: Meiosis & Sexual reproduction. Learn vocabulary, terms, and more with flashcards, games, and other study tools. It involves the formation of haploid sex cells or gametes, called sperms and ova, from diploid primary germ cells, called gametogonia, present in the reproductive organs called gonads (testes in male and ovaries in female).

The process follows fertilization, with the transfer being triggered by the activation of a cyclin-dependent kinase complex. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote.

List of related literature:

The experiences of the incubating individual, the mother, beginning with the fusion of the two gametes, formation of the zygote, through the placentation period (incubation), are always relevant to the activities of the gametes.

“Encyclopedia of Women and Gender, Two-Volume Set: Sex Similarities and Differences and the Impact of Society on Gender” by Judith Worell
from Encyclopedia of Women and Gender, Two-Volume Set: Sex Similarities and Differences and the Impact of Society on Gender
by Judith Worell
Elsevier Science, 2001

Importance of gametes and zygote in sexual reproduction: Gametes are prerequisite for the sexual reproduction.

“Oswaal NCERT Exemplar (Problems solutions) Class 10 Science (For 2021 Exam)” by Oswaal Editorial Board
from Oswaal NCERT Exemplar (Problems solutions) Class 10 Science (For 2021 Exam)
by Oswaal Editorial Board
Oswaal Books, 2020

When fertilisation occurs the sperm and the ovum unite, each contributing 23 chromosomes to the zygote, making a total of 46 chromosomes in 23 pairs, which are replicated in every cell of the body as the embryo develops.

“Tabbner's Nursing Care: Theory and Practice” by Gabby Koutoukidis, Rita Funnell, Gabrielle Koutoukidis, Karen Lawrence, Jodie Hughson, Kate Stainton
from Tabbner’s Nursing Care: Theory and Practice
by Gabby Koutoukidis, Rita Funnell, et. al.
Elsevier Australia, 2008

Importance of gametes and zygote in sexual reproduction: Gametes are the reproductive cells which actually take part in sexual fertilisation.

“Educart NCERT Science Exemplar Class 10 (With Reduced Syllabus For 2021): Educart” by Educart
from Educart NCERT Science Exemplar Class 10 (With Reduced Syllabus For 2021): Educart
by Educart

The importance of genomic imprinting is demonstrated by the observation that an embryo derived from the transplantation of two male or two female pronuclei into an ovum fails to develop (pronuclei are the nuclei of mature sperm and ova before they fuse during fertilization).

“Biochemistry” by Donald Voet, Judith G. Voet
from Biochemistry
by Donald Voet, Judith G. Voet
Wiley, 2010

The fertilized egg (zygote) develops into an embryo, the progenitor of the next generation, and the fertilized central cell forms the endosperm tissue, the main source of nutrition for the developing and germinating embryo.

“Plant Tissue Culture: An Introductory Text” by Sant Saran Bhojwani, Prem Kumar Dantu
from Plant Tissue Culture: An Introductory Text
by Sant Saran Bhojwani, Prem Kumar Dantu
Springer India, 2013

Sexual reproduction requires the fusion of male and female gametes (sperm and egg) to form a fertilized egg (zygote).

“The Science of Stem Cells” by Jonathan M. W. Slack
from The Science of Stem Cells
by Jonathan M. W. Slack
Wiley, 2018

Since the egg and the sperm each provide one-half of the total complement of chromosomes, the fertilized egg (zygote) constitutes the first complete cell of the developing organism from which all other cells develop.

“The Dictionary of Psychology” by Raymond J. Corsini
from The Dictionary of Psychology
by Raymond J. Corsini
Brunner/Mazel, 2002

» Zygote: This is the diploid cell that comes into existence when the sex cells (ovum and sperm, both haploid) fuse at conception.

“Anatomy & Physiology For Dummies” by Erin Odya, Maggie A. Norris
from Anatomy & Physiology For Dummies
by Erin Odya, Maggie A. Norris
Wiley, 2017

The zygote develops by fusion (fertilization: cytogamy and karyogamy) of haploid egg and sperm (anisogametes) that form an embryo, the blastula.

“Kingdoms and Domains: An Illustrated Guide to the Phyla of Life on Earth” by Lynn Margulis, Michael J Chapman
from Kingdoms and Domains: An Illustrated Guide to the Phyla of Life on Earth
by Lynn Margulis, Michael J Chapman
Elsevier Science, 2009

Oktay Kutluk

Kutluk Oktay, MD, FACOG is one of the world's foremost experts in fertility preservation as well as ovarian stimulation and in vitro fertilization for infertility treatments. He developed and performed the world's first ovarian transplantation procedures as well as pioneered new ovarian stimulation protocols for embryo and oocyte freezing for breast and endometrial cancer patients.

Mail: [email protected]
Telephone: +1 (877) 492-3666

Bibliography: oktay_bibliography

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  • Sir pzz make vidios about organic chemistry: basic concepts like classification and nomenclature of organic chemistry,isomerism and about redox reactionss

  • If you happen to be an infertile partners, please try the ThePregnancyFact. Com The results that western medicine provided me was aggravating However, my pregnancy was a success after getting a nutritious diet and going through scheduled acupuncture therapies for a few months. Viewing my 1 year old girl wandering in front of me makes me ecstatic. have much concerning this excellent formula from Google.?

  • Pssst… we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!
    Download it here for Apple Devices:
    Download it here for Android Devices:

  • I was introduced to your videos last semester in A&P1 and have watched you since! But this semester I was introduced to your history lessons AND I saw you in some art assignment videos! You’ve changed a lot in the years! Good for you, can’t wait to see what you teach next 😉

  • I love how these guys spend money on making videos for YouTube and then make errors in their videos but water mark them in case some kid wants to copy and upload CL’s content onto their channel with 12 subs..

  • As i’m watching this all i’m thinking about is how aliens won’t have to abduct and vivisect us to learn about us anymore, they can just watch crash course. ps: i’m definitely not an alien who’s researching the human race right now to instruct our military on how exactly to defeat you.

  • Are the cells called ‘blastomere’ only when the embryo becomes a morula, or is the cells in two-cell stage known as ‘blastomeres’? Thank you.

  • It is too wrong because
    Morula have only less then 8 blastomeres
    And in this video you have seen much of blastomere in morula
    It is too wrong����

  • So what I’ve learned here…is either you were hungry and had food on the mind when voicing over this, or embryos are just very food-like. We got mulberries, melons, pancakes, syrup, and then I was reminded a bit of a burger and a hot dog.

  • Hi u seem so clear with picture quality and please don’t make mistakes while teaching as u’ve made in “abdominal aorta” explanation video. They were not minor mistakes but they were major,u completely altered the source of a many arteries.hope u won’t repeat the mistake again cuz I’m planning to watch ur videos for exam preparation.i May have to be more cautious though while watching,checking out on google or my text book if that’s right.

  • My sketch pad says
    -“8weeks: all internal organs formed; budding limbs, hands, feet form”
    -“12weeks: all major organs functioning; fetus”
    It’s most vulnerable to damage from drugs and infections in the first eight.
    AMA Guide To Your Family’s Symptoms, copyright 1990

  • Really inaccurate. The blastomeres keep on decreasing in size while the embryo has the same volume as the zygote up till later stages

  • I was thinking that since human has two ovaries, why each month only one egg is got matured. Finally got this to share with you, so amazing:

    Your ovaries take turns, but they don’t play fair.

    Most women have two ovaries, one on the right and one on the left. During the first week or so after your period begins, both ovaries are hard at work growing follicles that could become mature eggs. However, around day 7, one egg becomes the dominant egg—let’s call her the Queen Egg—and the other follicles in both ovaries take a load off, eventually degenerating. (These otherwise “lost” eggs are the ones that are matured, retrieved, and preserved during egg freezing!) The Queen Egg continues to grow in preparation for her release around day 14.

    Each month, only one ovary develops a Queen Egg. (Typically, that is. The presence of multiple Queen Eggs could mean the release of both during ovulation—resulting in the possibility of a fraternal twin pregnancy if both are fertilized!) But which ovary develops the Queen isn’t a simple left-right-left-right alternation, nor is it purely random. Multiple studies (1, 2, 3) have demonstrated that, likely due to anatomical differences between the right and left sides of the reproductive system, the right ovary is significantly more likely to serve as the palace for your Queen Egg.

  • During sperm entering into secondary oocte which one is firstly entering in secondary oocyte (sperm proximal centriole/sperm nucleus)

  • leaving out very important information here

    both the neural plate + crest differentiate from the ectoderm and are induced by the formation of notochord (which is axial mesoderm)

    neural tube is formed by the neural plate which forms the CNS

    neural crest forms the CNS

    meh where is Sal?

  • The inner cell mass does not move to one end by itself it’s is pushed by the in flowing uterine fluid. Missing some details brother.

  • Hi there, hopefully someone can clear this up. From my understanding, hCG is an endocrine process (meaning it travels through the blood stream) this is also how pregnancy tests work, as hCG is filtered through the blood it also goes through the kidney for excretion in the urine, thus, pee on the stick, the stick recognizes hCG and indicates pregnancy. Does it talk to the corpus luteum through endocrine or is it more of a paracrine automation? Thanks

  • fun fact: the “pull-out method” is an official scientific method of natural contraception, and it has a name. it is called “coitus interruptus”. have fun

  • Allah is our creator and surely we have to return one day, to Him. So please do embrace Islam, Non Muslims(please don’t think I am presuring you whoever is reading this comment) just telling you the right path. Ik you will surely find the right path IF Allah the Almighty wills. My Good Luck is always with you ❤and…..

    Surely Allah the Almighty loves you too❤

  • Human creation in Quran

    وَلَقَدۡ خَلَقۡنَا ٱلۡإِنسَٰنَ مِن سُلَٰلَةٖ مِّن طِينٖ

    We have created man from an extract of clay.
    (Surah Al-Mu’minun, verse 12)

    ثُمَّ جَعَلۡنَٰهُ نُطۡفَةٗ فِي قَرَارٖ مَّكِينٖ

    Then We made him a sperm-drop in a firm resting place.
    (Surah Al-Mu’minun, verse 13)

    ثُمَّ خَلَقۡنَا ٱلنُّطۡفَةَ عَلَقَةٗ فَخَلَقۡنَا ٱلۡعَلَقَةَ مُضۡغَةٗ فَخَلَقۡنَا ٱلۡمُضۡغَةَ عِظَٰمٗا فَكَسَوۡنَا ٱلۡعِظَٰمَ لَحۡمٗا ثُمَّ أَنشَأۡنَٰهُ خَلۡقًا ءَاخَرَۚ فَتَبَارَكَ ٱللَّهُ أَحۡسَنُ ٱلۡخَٰلِقِينَ

    Then We turned the sperm-drop into a clot, then We turned the clot into a fetus-lump, then We turned the fetus-lump into bones, then We clothed the bones with flesh; thereafter We developed it into another creature. So, glorious is Allah, the Best of the creators.

    (Surah Al-Mu’minun, verse 14)

  • I have question:
    I know meiosis for Sperm and egg which are haploid cell. As u said at end of video, Sperm and egg combine and fertilization occur and after that Mitotic occur
    But how premeiotic cell is diploid and have parental homologous and maternal homology
    Supposed this sperm still didnot fertilize egg yet

  • Is there a possibility you could make a website with practice quizzes on the videos you do? For me its it’s a good way to know how much I understand and what I need to study more. Thank you. Your great I have returned to school after a 30 year break and you have saved this old lady!!

  • Here is what makes it impossible for The Quran  to be authored by a 7th century illeterate arab!:



    Existence of barriers which slow & control the mixing between fresh 

    & salt water in the seas so that each water keeps its 

    characteristics & species:

    ”He has set free the two seas meeting together. There is a barrier 

    between them. They do not transgress (each other).” (Quran, 55:19-20)


     is the one who has set free the two kinds of water, one sweet and 

    palatable, and the other salty and bitter. And He has made between them a

     barrier and a forbidding partition.” (Quran, 25:53)



    The prefrontal cortex (the frontal part of the 

    brain) is responsible for making our decisions, manipulating, lying,..etc

    Quran 96:15 ”Nay, if he(God’s enemy) desist not, We shall most surely drag him down upon his forehead(in the judgement day)


     A lying, sinful forehead!”



    IRON has meteoric origin in our solar system(sent down to Earth & 

    sunk to the core):’And We sent down iron, in which is great power, and 

    many benefits for humanity,…'(Quran, chapter Iron 57:25)

    This miracle exists in Quran’s copies which consider ‘Basmalah’ as the 

    1st verse (Basmala is the sentence ‘In the name of God,the mercifull’ at

     the head of each chapter).

    Thus,the verse 25 becomes 26(Iron’s Atomic number). The number of verses

     29 becomes 30(iron’s neutrons).Chapter 57 is the core of the Quran(114 

    chapters). 57 is a stable isotope of iron. Iron has the second most 

    tightly bound nuclei(Nuclear binding energy).



    In The following verses God mentions his ability (in judgement day) to 

    recreate not only the bones/skeleton after decomposition in the grave, 

    but more difficult than that: the tips of fingers (this refers to the 

    complexity of each paerson’s fingerprints):

    75:3 Does man (a disbeliever) thinks that We shall not assemble his 

    bones (in the hereafter)?

    75:4 Nay, We are Able to put together in perfect order the tips of his




    Quran, 51:47 “And the firmament, We constructed with power and skill and verily We are expanding it.


    BIG CRUNCH & ANOTHER BIG BANG (Cyclic universe hypothsis):

    Quran, 21:104

    “The Day that We roll up the heavens like a scroll rolled up for books 

    ,even as We produced the first creation, so We will also reproduce it:

     a promise We have undertaken: truly shall We fulfill it.


     They have not appraised Allah with true appraisal, while the earth(s) 

    entirely will be [within] His grip on the Day of Resurrection, and the 

    heavens will be folded in His right hand. Exalted is He and high above 

    what they associate with Him.


     [It will be] on the Day the earth will be replaced by another earth, 

    and the heavens [as well], and all creatures will come out before Allah,

     the One, the Prevailing.



    The scientific translation of the verses of embryology:

    Q22:5 O mankind! if you are in doubt concerning the Resurrection, then 

    lo! We (inform you that we ) have created you from a gamete/ovum, then 

    from a zygote, then from an Blastocyst/adherent, then 

    from a disc which is differentiated and not differentiated…


    Q 23:12 And indeed We created man out of a species/progeny/life form which originated from 

    clay. (12) Thereafter We made him  into a Zygote  in a welcoming stable 

    lodging (endometrium). (13) Then We made the zygote into a Blastocyst/adherent, then We made 

    the Blastocyst/adherent into a disc, then We made out of the disc bones (notochord), 

    then We clothed the bones with muscles, and then We made him into 

    another creation. So Blessed is Allâh, the Best of creators

    Adam was a modern human who was created from a female like jesus. He was not the first man:

    Quran 3:59
    Truly, the likeness of Jesus, in God’s sight, is as Adam’s likeness; He created him from a gamete/ovum, then said He unto him, ‘Be,’ and he was being.

    The three germ layers & three prenatal stages:

    Q39:6 He creates you in the bellies of your mothers,  creation after 

    creation, in a threefold darknesses.

    Notochord’s function as axis for muscles attatchment:
    Endometrium receptivity:



    (Qur’an, 21:32)

    We made the sky a preserved and protected roof yet still they turn away from its Signs.

    . The reflecting function of earth’s atmosphere:

    [I swear] by the sky which has returning/feedback properties. (Qur’an, 86:11)

    9 –


    “( I swear ) by Heaven and The Knocker! And what will convey to you 

    what The Knocker is? It is The Piercing Star! (Qur’an, 86:1-3) “



    Quran 6:125

    So who God wants that He guides him, He expands his chest to the 

    Islam/submission (to God); And who He wants that He misguides him, He 

    makes his chest narrow/tight, constricted, embarrassed as if (he) 

    ascends in the sky. Like that God makes/puts the obscenity/punishment 

    on those who do not believe.



    Plants begin to produce oxygen at down.

    Quran 81:18

     And (i swear ) by the dawn when it breathes/sighs

    12 –


    How & why the great pyramid of Giza was built? Exclusively in The 

    Holy Quran:

    Why the pyramids were built?:

    The pyramids were alligned with some stars because Pharaoh of the exodus

     somehow wanted to ascend or to find some celestial ways in order to 

    watch the god of Moses (perhaps they used to climb up the pyramid & 

    they also used it to project light up to the sky ):

    Quran 40:36 And Pharaoh said, “O Haman, construct for me a tower that I might reach the ways –


     The ways into the heavens so that I may look at the deity of Moses; 

    but indeed, I think he is a liar.” And thus was made attractive to 

    Pharaoh the evil of his deed, and he was averted from the [right] way. 

    And the plan of Pharaoh was not except in ruin.

    How the pyramids were built?:

    It is first discovered by Joseph Davidovits(material scientist) then 

    supported by  Michel Barsoum(materials science researcher) that the 

    blocks of the pyramids are not natural. but they are just moulded 

    concrete bricks of clay,lime & water then heated. 

    Quran 28:38

     And Pharaoh said, “O eminent ones, I have not known you to have a god 

    other than me. Then ignite for me, O Haman, [fire] upon the clay and 

    make for me a tower that I may look at the God of Moses. And indeed, I 

    do think he is among the liars.”

    Experiment of building a pyramid by the owner of this theory:




    Sea floor spreading subducted slabs:

    Q 15:19 And the earth-We had expanded it and CAST/THREW 

    anchors/stabilizers into it.

    The subducted slabs in the trenches  prevent planet earth’s poles 

    shift (crust displacement)by acting as anchors for the plates or by 

    distributing mass inside earth. Underground caves-rivers allow 

    scientific research:

    Q 16:15 And He had CAST/THROWN anchors/stabilizers into The Earth so that

     it does not shift/sway with you ; and rivers, and paths(caves), so that

     you will be guided.

    Subducting slabs act as sea anchor:

    Vietnam cave:


    True Polar Wander Hypothesis ( A Planet’s shift as a response to an 

    unballance in the distribution of landmasses):

    Q 78:6-7 ”Haven’t we made (planet) earth a prepared place /cradle and 

    mountains/landmasses as pegs/guy ropes?”

    . Q 21:31 And We have MADE in the earth anchors/stabilizers(mountains) so

     that it should not shift

      with them. 

    . Q 41:10 And He made therein anchors/stabilizers (mountains) from above 


    .Q27:61 Is He [not best] who made the planet Earth a stable place and 

    made within it rivers and made anchors/stabilizers FOR it…?

    .Q77:27 And We made lofty anchors/stabilizers(mountains) in it

    Surface loading & plenet stability: 

    The distribution of mountains as observed on planet Io:

    True Polar Wander hypothesis:

    Find the correct translation here: 



    . The miracle of Code 19 in The Quran, an astonishing mathematical combinations beyond human capability!:

    A video by Rashad Khalifa, the discoverer of this miracle himself:
    More maths:
    Many more hints and mathematical formulas are pending to be discovered in The Quran as a gift for its readers/researchers.

  • zack,my main man, my teacher, my master, i have my physio exam in 5 days pray i pass bro. if i pass im donating 20$ cause it was all thanks to you guys.

  • Zona pellucida doesn’t disintegrate.
    Due to the pressure developed by growing blastocoel a slit is produced in it and blastocyst squeezes out through it.
    During this process it may split into two forming monozygotic/ identical twins.

  • How cute I think this is happily feeling for all of mothers but sometimes its a dengerous for our mother so PlZ respect of all mothers infact all girls☺

  • Uh are really put your 1000 % oh my god I m shocked. Till now I m not watching this type of teaching videos�� thank a lot.. it’s really useful.. makes me to learn more.. god bless uh sir

  • Fantastic video! I’m a 1st Year UK Med student who was very confused after Embryology lecturesbut this really cleared things up… Thank you!

  • إلهي ما خلقت هذا باطلا
    سبحانك انا كنا من الظالمين

    أن تعدوا نعمه الله لا تحصوها سبحانك يا رحيم.يا خالقي ومنقذي ومنجي وناصري ومولأي
    اللهم ارزقني طريق في الطب لا اضل بعده ولا أتعب ����
    واني أسألك حسن الختام،،
    14 أيار 2020

  • 16 celled stage is first called Morula not 32 celled stage. Please do proper research and Please give a little information about your qualification before starting lectures.

  • Good job but you went way to fast for me. Plus you would talk about one drawing & start to draw the primitive streak but you wouldn’t move the screen over so I thought you were talking about another drawing ����‍♀️����

  • Hey, really helpful video however, if you could add a note that hypoblast doesn’t give rise to endoderm at around 8th minute that’d be grand, you never say it does but the colours might make someone get it wrong:)

  • Its nearly 1am on the day of my A+P 2 final… It’s a 4-year-old video and still reviewed everything I needed to review for this concept… I’m a college student. Crash Course has always been a blessing for finals!!!!

  • I just realize that from the begining there are warrior, that sacrifice him selft to complete the mission, bring the seed meet the queen. Then I compare with the things that I have done and achieved today, it’s just nothing to this. So let’s do the best story for the one that already complete their mission, we also have to do the same for the world and have the right reason for our own mission.

  • Amazing music for this incredible creation of life. Nothing seems to be more interesting than understanding this (including some others too) incredible journey of our universe and humankind. The way it gives life to live is one of the moment to be beholden.

  • After this video, the world is gonna face a sheer decline in population, due to the fact that every single female is now afraid of having a baby

  • This is an explicit explanation, thanks very much.

    Join me on my channel let’s talk one on one if you’re having problems conceiving

  • After crossing over what is ghe use it continues to 4 daughter cells remaining in the same body. Or does it enhance different body parts. Please help me I am soo confused ����������

  • Indeed Dr. Umoru is a great doctor. I want to use this opportunity to thank Dr. Umoru for saving me from Herpes. After using different pills and Herb’s still no result. I am here to testify of how I was cured from Herpes after using the medications I got from Dr. Umoru who I came across on YouTube You can contact this great doctor on any issues you are Suffering from via email [email protected] com or WhatsApp/call him on +2348165436638