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Hannah
10/12/2025
Biology
Fertilisation and implantation - biology
154
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10 Dec 2025
•
Fertilisation and Implantation in Humans and Plants - Biology Study
Hannah
@hannah_studys1012
1 / 3
The Great Sperm Race
Think of fertilisation as the ultimate obstacle course - one where only the strongest survive! Out of roughly 300 million sperm that begin this journey, most don't even make it past the starting line.
The acidic conditions in the vagina kill many sperm immediately, whilst others get trapped in thick mucus along the way. Your body's immune system treats sperm as foreign invaders, destroying even more. Those that survive must swim against powerful currents created by cilia in the fallopian tubes - imagine swimming upstream in a rushing river!
Here's where it gets really clever: chemicals near the egg make the remaining sperm hyperactive, giving them a final burst of speed. Only a few dozen survivors out of 300 million actually reach the egg.
The winning sperm attaches to special receptors on the zona pellucida (the egg's protective outer layer) and releases digestive enzymes to break through. Once one sperm makes contact, the egg immediately creates an impenetrable fertilisation membrane - it's like slamming the door shut on all the other competitors!
Quick Fact: Internal fertilisation in humans prevents the embryo from drying out, unlike external fertilisation in fish where millions of eggs and sperm are released into water.
From Single Cell to Implantation
After fertilisation, your body performs an amazing transformation that happens without you even knowing it. The fertilised egg, now called a zygote, begins dividing rapidly whilst staying exactly the same size - pretty mind-blowing, right?
This ball of cells becomes a morula, then develops into something called a blastocyst. Picture a hollow ball where the outer cells will eventually become the placenta, and the inner cluster becomes the actual baby. The protective zona pellucida disappears, allowing the blastocyst to "hatch" and prepare for the next crucial step.
Implantation happens when this tiny ball of cells burrows into the thick, nutrient-rich lining of the uterus. The outer cells immediately start forming what will become the placenta - your baby's lifeline for the next nine months. This usually occurs about 6-7 days after fertilisation.
Meanwhile, in the plant world, fertilisation works differently but just as cleverly. Pollen grains don't swim like sperm - instead, they grow long tubes down through the flower's style, carrying two male nuclei towards the female ovule.
Did You Know: The blastocyst contains embryonic stem cells that can become any type of cell in the human body!
Plant Fertilisation - Double the Action
Plants have mastered something called double fertilisation - and yes, it's as interesting as it sounds! When a pollen grain lands on a flower's stigma, it's just the beginning of an incredible process.
The pollen tube grows down through the style like a microscopic straw, guided by chemical signals from the ovule below. Inside this tube, two male nuclei travel towards their destination - but they each have different jobs to do.
Here's where the "double" part kicks in: the first male gamete fuses with the female egg nucleus to create a diploid zygote (which becomes the plant embryo). Simultaneously, the second male gamete fuses with two polar nuclei to form a triploid endosperm nucleus.
That triploid endosperm becomes the food supply for the developing plant embryo - think of it as a packed lunch that will fuel the seed during germination. It's like getting fertilisation and meal prep sorted in one go!
This double fertilisation is unique to flowering plants and explains why they've been so successful. Every seed contains both the baby plant and its own food supply, giving it the best possible start in life.
Plant Power: This double fertilisation process happens in over 250,000 flowering plant species - from tiny daisies to massive oak trees!
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
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This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
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Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
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Best app on earth! no words because it’s too good
Thomas R
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Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Fertilisation and Implantation in Humans and Plants - Biology Study
Hannah
@hannah_studys1012
Ever wondered how new life actually begins? Fertilisation is the incredible journey where sperm meets egg, but it's far more complex and fascinating than you might think. From the millions of sperm that start the race to the single cell... Show more
The Great Sperm Race
Think of fertilisation as the ultimate obstacle course - one where only the strongest survive! Out of roughly 300 million sperm that begin this journey, most don't even make it past the starting line.
The acidic conditions in the vagina kill many sperm immediately, whilst others get trapped in thick mucus along the way. Your body's immune system treats sperm as foreign invaders, destroying even more. Those that survive must swim against powerful currents created by cilia in the fallopian tubes - imagine swimming upstream in a rushing river!
Here's where it gets really clever: chemicals near the egg make the remaining sperm hyperactive, giving them a final burst of speed. Only a few dozen survivors out of 300 million actually reach the egg.
The winning sperm attaches to special receptors on the zona pellucida (the egg's protective outer layer) and releases digestive enzymes to break through. Once one sperm makes contact, the egg immediately creates an impenetrable fertilisation membrane - it's like slamming the door shut on all the other competitors!
Quick Fact: Internal fertilisation in humans prevents the embryo from drying out, unlike external fertilisation in fish where millions of eggs and sperm are released into water.
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From Single Cell to Implantation
After fertilisation, your body performs an amazing transformation that happens without you even knowing it. The fertilised egg, now called a zygote, begins dividing rapidly whilst staying exactly the same size - pretty mind-blowing, right?
This ball of cells becomes a morula, then develops into something called a blastocyst. Picture a hollow ball where the outer cells will eventually become the placenta, and the inner cluster becomes the actual baby. The protective zona pellucida disappears, allowing the blastocyst to "hatch" and prepare for the next crucial step.
Implantation happens when this tiny ball of cells burrows into the thick, nutrient-rich lining of the uterus. The outer cells immediately start forming what will become the placenta - your baby's lifeline for the next nine months. This usually occurs about 6-7 days after fertilisation.
Meanwhile, in the plant world, fertilisation works differently but just as cleverly. Pollen grains don't swim like sperm - instead, they grow long tubes down through the flower's style, carrying two male nuclei towards the female ovule.
Did You Know: The blastocyst contains embryonic stem cells that can become any type of cell in the human body!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Plant Fertilisation - Double the Action
Plants have mastered something called double fertilisation - and yes, it's as interesting as it sounds! When a pollen grain lands on a flower's stigma, it's just the beginning of an incredible process.
The pollen tube grows down through the style like a microscopic straw, guided by chemical signals from the ovule below. Inside this tube, two male nuclei travel towards their destination - but they each have different jobs to do.
Here's where the "double" part kicks in: the first male gamete fuses with the female egg nucleus to create a diploid zygote (which becomes the plant embryo). Simultaneously, the second male gamete fuses with two polar nuclei to form a triploid endosperm nucleus.
That triploid endosperm becomes the food supply for the developing plant embryo - think of it as a packed lunch that will fuel the seed during germination. It's like getting fertilisation and meal prep sorted in one go!
This double fertilisation is unique to flowering plants and explains why they've been so successful. Every seed contains both the baby plant and its own food supply, giving it the best possible start in life.
Plant Power: This double fertilisation process happens in over 250,000 flowering plant species - from tiny daisies to massive oak trees!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Most popular content: Fertilization
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Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user