Overall Summary
This guide covers key concepts in Inheritance, variation... Show more
Subjects
Careers
Energy transfers (a2 only)
Infection and response
Homeostasis and response
Responding to change (a2 only)
Cell biology
Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
The control of gene expression (a2 only)
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Ecology
Cells
Show all topics
World war two & the holocaust
2o democracy and nazism: germany, 1918-1945
Medieval period: 1066 -1509
2m wars and welfare: britain in transition, 1906-1957
1l the quest for political stability: germany, 1871-1991
1f industrialisation and the people: britain, c1783-1885
Britain & the wider world: 1745 -1901
2d religious conflict and the church in england, c1529-c1570
The cold war
1c the tudors: england, 1485-1603
Inter-war germany
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
World war one
Britain: 1509 -1745
Show all topics
439
•
24 Jun 2025
•
Olamide
@olamide_26
Overall Summary
This guide covers key concepts in Inheritance, variation... Show more
Genetic Diseases and Key Genetic Terms
This section delves into genetic diseases and introduces essential terminology in genetics. It uses two specific genetic disorders as examples to illustrate inheritance patterns.
Example: Polydactyly, characterized by extra fingers and toes, is caused by a dominant allele, while cystic fibrosis, a disorder affecting cell membranes, is caused by a recessive allele.
The guide provides a comprehensive list of key genetic terms, including DNA, gene, chromosome, genome, allele, dominant, recessive, homozygous, heterozygous, genotype, and phenotype.
Definition: A gene is a small section of DNA on a chromosome that codes for a particular sequence of amino acids, which make a protein.
The section also explains the difference between single gene characteristics and multiple gene characteristics.
Highlight: Most characteristics are controlled by many genes, such as height, while some characteristics are controlled by only one gene, like fur color in mice or color blindness in humans.
The guide then focuses on gender inheritance in humans, explaining the role of sex chromosomes and using a Punnett square to illustrate sex inheritance patterns.
Vocabulary: Human body cells contain 23 pairs of chromosomes, with 22 pairs controlling characteristics and one pair controlling sex. Males have XY chromosomes, while females have XX chromosomes.
Sexual and Asexual Reproduction
This section introduces the fundamental concepts of sexual and asexual reproduction in biology. It covers the key differences between these two reproductive methods and their implications for genetic variation.
Definition: Sexual reproduction involves the fusion of gametes, while asexual reproduction involves only one parent and no gametes.
The guide explains the roles of gametes, meiosis, and fertilization in sexual reproduction. It also highlights that asexual reproduction produces genetically identical clones through mitosis.
Vocabulary: Gametes are sex cells containing half the genetic information of a body cell, such as sperm and egg in animals or pollen and ovaries in plants.
The section compares mitosis and meiosis, detailing the number of daughter cells produced, genetic variation, and their purposes in organisms.
Highlight: Meiosis produces four genetically different daughter cells, each with half the genetic information of a body cell, while mitosis produces two identical daughter cells with the full amount of chromosomes.
The advantages and disadvantages of sexual reproduction and asexual reproduction are discussed, providing a balanced view of both reproductive strategies.
Example: Sexual reproduction produces variation, making offspring more likely to survive environmental changes and diseases, while asexual reproduction allows organisms to produce many offspring quickly without needing a mate.
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
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
Olamide
@olamide_26
Overall Summary
This guide covers key concepts in Inheritance, variation and evolution GCSE Biology, focusing on sexual and asexual reproduction, genetic inheritance, and evolutionary processes. It provides comprehensive information on:
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Genetic Diseases and Key Genetic Terms
This section delves into genetic diseases and introduces essential terminology in genetics. It uses two specific genetic disorders as examples to illustrate inheritance patterns.
Example: Polydactyly, characterized by extra fingers and toes, is caused by a dominant allele, while cystic fibrosis, a disorder affecting cell membranes, is caused by a recessive allele.
The guide provides a comprehensive list of key genetic terms, including DNA, gene, chromosome, genome, allele, dominant, recessive, homozygous, heterozygous, genotype, and phenotype.
Definition: A gene is a small section of DNA on a chromosome that codes for a particular sequence of amino acids, which make a protein.
The section also explains the difference between single gene characteristics and multiple gene characteristics.
Highlight: Most characteristics are controlled by many genes, such as height, while some characteristics are controlled by only one gene, like fur color in mice or color blindness in humans.
The guide then focuses on gender inheritance in humans, explaining the role of sex chromosomes and using a Punnett square to illustrate sex inheritance patterns.
Vocabulary: Human body cells contain 23 pairs of chromosomes, with 22 pairs controlling characteristics and one pair controlling sex. Males have XY chromosomes, while females have XX chromosomes.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Sexual and Asexual Reproduction
This section introduces the fundamental concepts of sexual and asexual reproduction in biology. It covers the key differences between these two reproductive methods and their implications for genetic variation.
Definition: Sexual reproduction involves the fusion of gametes, while asexual reproduction involves only one parent and no gametes.
The guide explains the roles of gametes, meiosis, and fertilization in sexual reproduction. It also highlights that asexual reproduction produces genetically identical clones through mitosis.
Vocabulary: Gametes are sex cells containing half the genetic information of a body cell, such as sperm and egg in animals or pollen and ovaries in plants.
The section compares mitosis and meiosis, detailing the number of daughter cells produced, genetic variation, and their purposes in organisms.
Highlight: Meiosis produces four genetically different daughter cells, each with half the genetic information of a body cell, while mitosis produces two identical daughter cells with the full amount of chromosomes.
The advantages and disadvantages of sexual reproduction and asexual reproduction are discussed, providing a balanced view of both reproductive strategies.
Example: Sexual reproduction produces variation, making offspring more likely to survive environmental changes and diseases, while asexual reproduction allows organisms to produce many offspring quickly without needing a mate.
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
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