Subjects

Careers

Open the App

Subjects

Free A Level Genetics Revision Notes PDF: Monohybrid & Dihybrid Crosses Explained

Open

111

5

user profile picture

Hameedah

10/07/2023

Biology

Topic 7 Genetics, populations, evolutions and ecosystems

Free A Level Genetics Revision Notes PDF: Monohybrid & Dihybrid Crosses Explained

Understanding genetics and inheritance patterns is fundamental to modern biology and helps explain how traits are passed from parents to offspring.

Genotype refers to the genetic makeup of an organism - the actual genes it carries, while phenotype is the physical expression of those genes - how the organism looks and functions. For example, in humans, having the genes for brown eyes would be the genotype, while the actual brown eye color is the phenotype. These concepts are crucial for understanding inheritance patterns studied through monohybrid and dihybrid crosses.

A monohybrid cross examines the inheritance of a single trait, like flower color in peas, where each parent carries two alleles for that trait. This helps demonstrate basic Mendelian inheritance patterns and probability. In contrast, a dihybrid cross looks at two traits simultaneously, such as both pea color and pod shape, showing how different characteristics are inherited independently. These crosses help predict offspring ratios and understand dominant and recessive traits. For instance, in human genetics, we can use these principles to understand how traits like blood type and eye color are inherited. The study of inheritance patterns through genetics has revolutionized our understanding of human health, agriculture, and evolution. Modern genetic techniques allow us to identify specific gene sequences responsible for traits and diseases, leading to breakthroughs in personalized medicine and crop improvement. Understanding these fundamental concepts in Biology is essential for students pursuing careers in medicine, research, or biotechnology.

Through careful study of inheritance patterns, scientists can predict the likelihood of certain traits appearing in offspring, understand genetic disorders, and develop treatments for genetic conditions. This knowledge has practical applications in breeding programs, genetic counseling, and developing disease-resistant crops. The field continues to evolve with new discoveries about gene expression, environmental influences on phenotype, and the complex interactions between different genes.

...

10/07/2023

1076

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Understanding Basic Genetics and Inheritance Patterns

Genotype and phenotype form the foundation of inheritance patterns in genetics. The genotype represents an organism's complete genetic makeup, while the phenotype is how those genes are expressed physically, influenced by both genetics and environmental factors.

Alleles are different versions of the same gene that can produce varying traits. For example, in human eye color, multiple alleles determine the final color we see. These alleles can be either homozygous sametypesame type or heterozygous differenttypesdifferent types when paired on homologous chromosomes. In the case of BB or bb, we have homozygous alleles, while Bb represents heterozygous alleles.

Dominant and recessive inheritance patterns play a crucial role in determining which traits are expressed. A dominant allele only needs one copy to show up in the phenotype, while recessive alleles require two copies to be expressed. This fundamental concept helps explain why some traits skip generations or appear unexpectedly in families.

Definition: Genotype definition Biology refers to the genetic constitution of an organism, while Phenotype definition Biology describes the observable characteristics resulting from gene expression and environmental influences.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Monohybrid Crosses and Co-dominance in Genetics

Monohybrid inheritance A level Biology involves studying how a single gene's traits are passed down through generations. Scientists use Punnett squares to predict offspring characteristics in these crosses. This systematic approach helps visualize potential genetic combinations and their probabilities.

Co-dominant alleles present an interesting case where both alleles have equal expression in the phenotype. The classic example is blood type AB, where both A and B alleles are fully expressed rather than one dominating the other. This demonstrates how genetic inheritance isn't always a simple dominant-recessive relationship.

When conducting genetic crosses, following a structured approach ensures accurate predictions. This includes identifying allele codes, parent phenotypes and genotypes, determining possible gametes, and completing Punnett squares to calculate offspring ratios.

Example: In a monohybrid cross between tongue-rolling TT and non-rolling tt traits, crossing TT × tt parents produces all Tt offspring in the first generation, all showing the rolling phenotype due to dominance.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Advanced Inheritance Patterns and Test Crosses

Test crosses serve as a powerful tool for determining unknown genotypes by crossing with homozygous recessive individuals. The resulting offspring ratios reveal whether the unknown parent is homozygous dominant, heterozygous, or homozygous recessive.

Dihybrid inheritance A level Biology examines the inheritance of two different genes simultaneously. This more complex pattern typically produces a 9:3:3:1 ratio in the F2 generation when both genes show complete dominance. Common examples include pea plant characteristics and coat color/eye color combinations in mice.

Understanding these patterns is crucial for predicting genetic outcomes in both natural populations and controlled breeding programs. The mathematical precision of genetic ratios helps scientists and breeders make informed decisions about potential crosses.

Highlight: Test crosses are essential tools in genetic analysis, providing clear evidence of an organism's genetic makeup through careful observation of offspring phenotypes.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Complex Inheritance Patterns and Chromosomal Linkage

Autosomal linkage occurs when genes are located on the same chromosome, affecting how traits are inherited together. The closer two genes are on a chromosome, the more likely they'll be inherited as a unit, unless separated by crossing over during meiosis.

Multiple allele systems, such as blood types, demonstrate how genetic inheritance can be more complex than simple dominant-recessive patterns. These systems show how different combinations of alleles can produce various phenotypes, expanding our understanding of genetic diversity.

The physical distance between genes on a chromosome theirlocitheir loci influences inheritance patterns significantly. Closer genes are more likely to be inherited together, creating characteristic patterns of linked traits in offspring. This concept is crucial for understanding genetic mapping and trait prediction.

Vocabulary: Autosomal linkage describes the tendency of genes located on the same chromosome to be inherited together, affecting trait distribution in populations.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Understanding Linked Genes and Sex Linkage in Genetics

Genetics biology notes pdf explains that linked genes are alleles inherited together because they are located close to each other on the same chromosome. This fundamental concept in inheritance a level Biology notes helps us understand how traits are passed down through generations.

Sex linkage occurs when genes are located on sex chromosomes XorYX or Y. In humans and many other organisms, females have two X chromosomes XXXX while males have one X and one Y chromosome XYXY. This creates unique inheritance patterns for genotype and phenotype definitions biology. The Y chromosome is significantly smaller than the X chromosome, meaning most sex-linked traits are carried on the X chromosome.

Definition: Sex-linked inheritance refers to the pattern of inheritance for genes located on sex chromosomes, particularly affecting how traits are expressed differently in males and females.

Males are more susceptible to recessive sex-linked conditions because they only have one X chromosome. If a male inherits a recessive disease allele on their X chromosome, they will express the condition. In contrast, females need to inherit two copies of the recessive allele to express the condition, making them more likely to be carriers rather than affected. Common examples include hemophilia and red-green color blindness.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Understanding Epistasis and Gene Interactions

Epistasis represents a crucial concept in genetics A level Biology notes PDF, where one gene's alleles can mask or modify the expression of another gene's alleles. This interaction creates inheritance patterns that deviate from typical monohybrid and dihybrid crosses explained pdf.

Highlight: Epistatic interactions can be either dominant or recessive. Dominant epistasis occurs when one dominant allele masks another gene's expression, while recessive epistasis requires two copies of the recessive allele.

The suppressing gene epistaticgeneepistatic gene influences the suppressed gene hypostaticgenehypostatic gene, resulting in phenotypic ratios that differ from standard Mendelian inheritance patterns. This complex interaction demonstrates how genotype and phenotype definitions aren't always straightforward.

Example: In coat color inheritance in some animals, epistasis can result in unexpected color patterns. For instance, an epistatic gene might prevent the expression of pigment entirely, resulting in white fur regardless of other color genes present.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Analyzing Genetic Data with Chi-Square Testing

The chi-square test is an essential statistical tool in genetics biology notes pdf for analyzing genetic inheritance patterns. This test helps determine whether differences between observed and expected results are statistically significant or due to chance.

Definition: The chi-square test compares observed genetic ratios with expected Mendelian ratios to determine if deviations are statistically significant.

The formula for chi-square is: χ² = ΣOEO-E²/E, where O represents observed values and E represents expected values. When analyzing results, scientists compare the calculated chi-square value to critical values at specific degrees of freedom. This analysis helps validate monohybrid and dihybrid cross Problems with answers PDF.

Understanding probability in genetics is crucial for predicting inheritance patterns. If the chi-square value exceeds the critical value, we reject the null hypothesis, indicating that differences are not due to chance. This statistical approach provides a foundation for analyzing dihybrid inheritance A level Biology.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Population Genetics and Hardy-Weinberg Principle

Population genetics examines how genetic variation is maintained and changed within populations. The genotype example in humans shows how different alleles persist in populations over time. A population consists of organisms of the same species that can potentially interbreed.

The Hardy-Weinberg principle provides a mathematical framework for understanding allele frequencies in populations. This principle states that allele frequencies remain constant unless specific factors intervene. These factors include mutation, non-random mating, natural selection, genetic drift, and gene flow.

Vocabulary: Gene pool refers to all genes present in a breeding population, while allele frequency describes how common specific alleles are within that population.

The Hardy-Weinberg equation p2+2pq+q2=1p² + 2pq + q² = 1 helps calculate genotype frequencies, where p represents the dominant allele frequency and q represents the recessive allele frequency. This mathematical tool is crucial for studying population genetics and understanding how genetic variation is maintained in populations.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

View

Understanding Population Genetics and Hardy-Weinberg Equilibrium

Population genetics helps us understand how traits are inherited and distributed within groups of organisms. The Hardy-Weinberg principle provides a mathematical framework for analyzing genotype and phenotype frequencies in populations.

Definition: The Hardy-Weinberg equilibrium states that allele frequencies remain constant in a population unless specific evolutionary forces are acting upon it.

Let's explore this concept through practical examples. In corn plants, purple kernels demonstrate dominance over yellow kernels. When examining a population sample of 100 kernels where 9 are yellow and 91 are purple, we can calculate allele frequencies. Since yellow is recessive, its frequency q2 equals 0.09, making q=0.3. This mathematical approach helps geneticists understand trait distribution in populations.

Another illustrative example involves wool color in sheep populations. When a population has white wool allele WW frequency of 0.19 and black wool allele ww frequency of 0.81, we can determine the percentage of heterozygous individuals. Using the formula 2pq wherep=0.19andq=0.81where p=0.19 and q=0.81, we calculate that approximately 31% of the population carries both alleles.

Example: In a sheep population:

  • White wool allele WW frequency = 0.19
  • Black wool allele ww frequency = 0.81
  • Heterozygous frequency = 20.190.190.810.81 = 0.3078 or 31%

Can't find what you're looking for? Explore other subjects.

Knowunity is the #1 education app in five European countries

Knowunity has been named a featured story on Apple and has regularly topped the app store charts in the education category in Germany, Italy, Poland, Switzerland, and the United Kingdom. Join Knowunity today and help millions of students around the world.

Ranked #1 Education App

Download in

Google Play

Download in

App Store

Knowunity is the #1 education app in five European countries

4.9+

Average app rating

21 M

Pupils love Knowunity

#1

In education app charts in 17 countries

950 K+

Students have uploaded notes

Still not convinced? See what other students are saying...

iOS User

I love this app so much, I also use it daily. I recommend Knowunity to everyone!!! I went from a D to an A with it :D

Philip, iOS User

The app is very simple and well designed. So far I have always found everything I was looking for :D

Lena, iOS user

I love this app ❤️ I actually use it every time I study.

 

Biology

1,076

10 Jul 2023

25 pages

Free A Level Genetics Revision Notes PDF: Monohybrid & Dihybrid Crosses Explained

user profile picture

Hameedah

@hameedah

Understanding genetics and inheritance patterns is fundamental to modern biology and helps explain how traits are passed from parents to offspring.

Genotype refers to the genetic makeup of an organism - the actual genes it carries, while phenotypeis the... Show more

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Understanding Basic Genetics and Inheritance Patterns

Genotype and phenotype form the foundation of inheritance patterns in genetics. The genotype represents an organism's complete genetic makeup, while the phenotype is how those genes are expressed physically, influenced by both genetics and environmental factors.

Alleles are different versions of the same gene that can produce varying traits. For example, in human eye color, multiple alleles determine the final color we see. These alleles can be either homozygous sametypesame type or heterozygous differenttypesdifferent types when paired on homologous chromosomes. In the case of BB or bb, we have homozygous alleles, while Bb represents heterozygous alleles.

Dominant and recessive inheritance patterns play a crucial role in determining which traits are expressed. A dominant allele only needs one copy to show up in the phenotype, while recessive alleles require two copies to be expressed. This fundamental concept helps explain why some traits skip generations or appear unexpectedly in families.

Definition: Genotype definition Biology refers to the genetic constitution of an organism, while Phenotype definition Biology describes the observable characteristics resulting from gene expression and environmental influences.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Monohybrid Crosses and Co-dominance in Genetics

Monohybrid inheritance A level Biology involves studying how a single gene's traits are passed down through generations. Scientists use Punnett squares to predict offspring characteristics in these crosses. This systematic approach helps visualize potential genetic combinations and their probabilities.

Co-dominant alleles present an interesting case where both alleles have equal expression in the phenotype. The classic example is blood type AB, where both A and B alleles are fully expressed rather than one dominating the other. This demonstrates how genetic inheritance isn't always a simple dominant-recessive relationship.

When conducting genetic crosses, following a structured approach ensures accurate predictions. This includes identifying allele codes, parent phenotypes and genotypes, determining possible gametes, and completing Punnett squares to calculate offspring ratios.

Example: In a monohybrid cross between tongue-rolling TT and non-rolling tt traits, crossing TT × tt parents produces all Tt offspring in the first generation, all showing the rolling phenotype due to dominance.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Advanced Inheritance Patterns and Test Crosses

Test crosses serve as a powerful tool for determining unknown genotypes by crossing with homozygous recessive individuals. The resulting offspring ratios reveal whether the unknown parent is homozygous dominant, heterozygous, or homozygous recessive.

Dihybrid inheritance A level Biology examines the inheritance of two different genes simultaneously. This more complex pattern typically produces a 9:3:3:1 ratio in the F2 generation when both genes show complete dominance. Common examples include pea plant characteristics and coat color/eye color combinations in mice.

Understanding these patterns is crucial for predicting genetic outcomes in both natural populations and controlled breeding programs. The mathematical precision of genetic ratios helps scientists and breeders make informed decisions about potential crosses.

Highlight: Test crosses are essential tools in genetic analysis, providing clear evidence of an organism's genetic makeup through careful observation of offspring phenotypes.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Complex Inheritance Patterns and Chromosomal Linkage

Autosomal linkage occurs when genes are located on the same chromosome, affecting how traits are inherited together. The closer two genes are on a chromosome, the more likely they'll be inherited as a unit, unless separated by crossing over during meiosis.

Multiple allele systems, such as blood types, demonstrate how genetic inheritance can be more complex than simple dominant-recessive patterns. These systems show how different combinations of alleles can produce various phenotypes, expanding our understanding of genetic diversity.

The physical distance between genes on a chromosome theirlocitheir loci influences inheritance patterns significantly. Closer genes are more likely to be inherited together, creating characteristic patterns of linked traits in offspring. This concept is crucial for understanding genetic mapping and trait prediction.

Vocabulary: Autosomal linkage describes the tendency of genes located on the same chromosome to be inherited together, affecting trait distribution in populations.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Understanding Linked Genes and Sex Linkage in Genetics

Genetics biology notes pdf explains that linked genes are alleles inherited together because they are located close to each other on the same chromosome. This fundamental concept in inheritance a level Biology notes helps us understand how traits are passed down through generations.

Sex linkage occurs when genes are located on sex chromosomes XorYX or Y. In humans and many other organisms, females have two X chromosomes XXXX while males have one X and one Y chromosome XYXY. This creates unique inheritance patterns for genotype and phenotype definitions biology. The Y chromosome is significantly smaller than the X chromosome, meaning most sex-linked traits are carried on the X chromosome.

Definition: Sex-linked inheritance refers to the pattern of inheritance for genes located on sex chromosomes, particularly affecting how traits are expressed differently in males and females.

Males are more susceptible to recessive sex-linked conditions because they only have one X chromosome. If a male inherits a recessive disease allele on their X chromosome, they will express the condition. In contrast, females need to inherit two copies of the recessive allele to express the condition, making them more likely to be carriers rather than affected. Common examples include hemophilia and red-green color blindness.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Understanding Epistasis and Gene Interactions

Epistasis represents a crucial concept in genetics A level Biology notes PDF, where one gene's alleles can mask or modify the expression of another gene's alleles. This interaction creates inheritance patterns that deviate from typical monohybrid and dihybrid crosses explained pdf.

Highlight: Epistatic interactions can be either dominant or recessive. Dominant epistasis occurs when one dominant allele masks another gene's expression, while recessive epistasis requires two copies of the recessive allele.

The suppressing gene epistaticgeneepistatic gene influences the suppressed gene hypostaticgenehypostatic gene, resulting in phenotypic ratios that differ from standard Mendelian inheritance patterns. This complex interaction demonstrates how genotype and phenotype definitions aren't always straightforward.

Example: In coat color inheritance in some animals, epistasis can result in unexpected color patterns. For instance, an epistatic gene might prevent the expression of pigment entirely, resulting in white fur regardless of other color genes present.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Analyzing Genetic Data with Chi-Square Testing

The chi-square test is an essential statistical tool in genetics biology notes pdf for analyzing genetic inheritance patterns. This test helps determine whether differences between observed and expected results are statistically significant or due to chance.

Definition: The chi-square test compares observed genetic ratios with expected Mendelian ratios to determine if deviations are statistically significant.

The formula for chi-square is: χ² = ΣOEO-E²/E, where O represents observed values and E represents expected values. When analyzing results, scientists compare the calculated chi-square value to critical values at specific degrees of freedom. This analysis helps validate monohybrid and dihybrid cross Problems with answers PDF.

Understanding probability in genetics is crucial for predicting inheritance patterns. If the chi-square value exceeds the critical value, we reject the null hypothesis, indicating that differences are not due to chance. This statistical approach provides a foundation for analyzing dihybrid inheritance A level Biology.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Population Genetics and Hardy-Weinberg Principle

Population genetics examines how genetic variation is maintained and changed within populations. The genotype example in humans shows how different alleles persist in populations over time. A population consists of organisms of the same species that can potentially interbreed.

The Hardy-Weinberg principle provides a mathematical framework for understanding allele frequencies in populations. This principle states that allele frequencies remain constant unless specific factors intervene. These factors include mutation, non-random mating, natural selection, genetic drift, and gene flow.

Vocabulary: Gene pool refers to all genes present in a breeding population, while allele frequency describes how common specific alleles are within that population.

The Hardy-Weinberg equation p2+2pq+q2=1p² + 2pq + q² = 1 helps calculate genotype frequencies, where p represents the dominant allele frequency and q represents the recessive allele frequency. This mathematical tool is crucial for studying population genetics and understanding how genetic variation is maintained in populations.

7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Understanding Population Genetics and Hardy-Weinberg Equilibrium

Population genetics helps us understand how traits are inherited and distributed within groups of organisms. The Hardy-Weinberg principle provides a mathematical framework for analyzing genotype and phenotype frequencies in populations.

Definition: The Hardy-Weinberg equilibrium states that allele frequencies remain constant in a population unless specific evolutionary forces are acting upon it.

Let's explore this concept through practical examples. In corn plants, purple kernels demonstrate dominance over yellow kernels. When examining a population sample of 100 kernels where 9 are yellow and 91 are purple, we can calculate allele frequencies. Since yellow is recessive, its frequency q2 equals 0.09, making q=0.3. This mathematical approach helps geneticists understand trait distribution in populations.

Another illustrative example involves wool color in sheep populations. When a population has white wool allele WW frequency of 0.19 and black wool allele ww frequency of 0.81, we can determine the percentage of heterozygous individuals. Using the formula 2pq wherep=0.19andq=0.81where p=0.19 and q=0.81, we calculate that approximately 31% of the population carries both alleles.

Example: In a sheep population:

  • White wool allele WW frequency = 0.19
  • Black wool allele ww frequency = 0.81
  • Heterozygous frequency = 20.190.190.810.81 = 0.3078 or 31%
7 Genetics, populations,
evolutions and ecosystems
EAS/A level A level
3.7.1 Inheritance
▼ Genotype
. The genetic constitution of an organis

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

Genetic Variation and Evolution: Foundations of Speciation

Understanding genetic variation is crucial for comprehending evolution and speciation. Genetics biology notes emphasize that individuals within species populations exhibit diverse phenotypes due to both genetic and environmental factors.

The primary source of genetic variation comes from mutations, which produce different alleles. This process is fundamental to evolution and creates the raw material for natural selection. During sexual reproduction, monohybrid and dihybrid crosses contribute to genetic diversity through multiple mechanisms.

Highlight: Key sources of genetic variation include:

  • Mutations creating new alleles
  • Meiosis involving independent segregation
  • Crossing over during genetic recombination
  • Random fertilization of gametes

Environmental factors also play a significant role in creating variation within populations. These include disease pressure, predation, and competition for resources. The interaction between genetic and environmental factors determines the ultimate phenotype expression in organisms.

Vocabulary: Independent segregation refers to the random separation of chromosomes during meiosis, while crossing over involves the exchange of genetic material between homologous chromosomes.

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

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