Select The Correct Answer.In A Particular Species Of Frogs, Black Spots Are A Dominant Trait, And Their Absence Is A Recessive Trait. In A Population Of Frogs, 50 Are Homozygous For The Dominant Trait, 34 Are Heterozygous Dominant, And 16 Show The

Mar 12, 2025 by ADMIN 248 views

**Understanding the Genetics of Frog Traits: A Dominant and Recessive Trait Analysis**

Introduction

In the world of genetics, traits are often determined by the interaction of dominant and recessive alleles. A dominant allele will always be expressed if an individual has one copy of the allele, while a recessive allele will only be expressed if an individual has two copies of the allele. In this article, we will explore the concept of dominant and recessive traits using the example of a particular species of frogs, where black spots are a dominant trait and their absence is a recessive trait.

Dominant and Recessive Traits

A dominant trait is a characteristic that will always be expressed if an individual has one copy of the allele. In the case of the frogs, the black spots are a dominant trait, meaning that if an individual has one copy of the dominant allele, they will have black spots. A recessive trait, on the other hand, will only be expressed if an individual has two copies of the allele. In this case, the absence of black spots is a recessive trait.

Genotype and Phenotype

The genotype of an individual refers to the genetic makeup of that individual, while the phenotype refers to the physical characteristics of that individual. In the case of the frogs, the genotype can be represented as follows:

BB: homozygous dominant (black spots)
Bb: heterozygous dominant (black spots)
bb: homozygous recessive (no black spots)

The phenotype of an individual can be determined by their genotype. For example, an individual with the genotype BB will have black spots, while an individual with the genotype bb will not have black spots.

Population Genetics

In a population of frogs, we can use the principles of population genetics to understand the distribution of the dominant and recessive traits. Let's assume that we have a population of 100 frogs, with the following distribution:

BB: 50 frogs (homozygous dominant)
Bb: 34 frogs (heterozygous dominant)
bb: 16 frogs (homozygous recessive)

Calculating the Genotype Frequencies

To calculate the genotype frequencies, we can use the following formula:

p: frequency of the dominant allele (B)
q: frequency of the recessive allele (b)

We can calculate the frequencies of the dominant and recessive alleles as follows:

p: 50 (homozygous dominant) + 34 (heterozygous dominant) = 84
q: 16 (homozygous recessive)

The frequency of the dominant allele (p) is 84/100 = 0.84, while the frequency of the recessive allele (q) is 16/100 = 0.16.

Calculating the Genotype and Phenotype Frequencies

Using the genotype frequencies, we can calculate the genotype and phenotype frequencies as follows:

BB: 50 (homozygous dominant)
Bb: 34 (heterozygous dominant)
bb: 16 (homozygous recessive)

The phenotype frequencies can be calculated as follows:

Black spots: 50 (homozygous dominant) + 34 (heterozygous dominant) = 84
No black spots: 16 (homozygous recessive)

Conclusion

In conclusion, the concept of dominant and recessive traits is a fundamental principle of genetics. By understanding the genotype and phenotype frequencies of a population, we can gain insights into the distribution of traits and the genetic makeup of individuals. In this article, we used the example of a particular species of frogs to illustrate the concept of dominant and recessive traits. By applying the principles of population genetics, we can calculate the genotype and phenotype frequencies of a population and gain a deeper understanding of the genetic mechanisms that underlie the distribution of traits.

References

Bateson, W. (1909). Mendel's Principles of Heredity. Cambridge University Press.
Fisher, R. A. (1915). The Genetical Theory of Natural Selection. Cambridge University Press.
Hardy, G. H. (1908). A Mathematician's Apology. Cambridge University Press.

Q: What is the difference between a dominant and recessive trait?

A: A dominant trait is a characteristic that will always be expressed if an individual has one copy of the allele, while a recessive trait will only be expressed if an individual has two copies of the allele.

Q: How do dominant and recessive traits interact?

A: When two alleles interact, the dominant allele will always be expressed. If an individual has one copy of the dominant allele and one copy of the recessive allele, the dominant allele will be expressed.

Q: What is the genotype of an individual with a dominant trait?

A: The genotype of an individual with a dominant trait can be represented as BB (homozygous dominant) or Bb (heterozygous dominant).

Q: What is the genotype of an individual with a recessive trait?

A: The genotype of an individual with a recessive trait is bb (homozygous recessive).

Q: How do you calculate the genotype frequencies in a population?

A: To calculate the genotype frequencies, you need to know the number of individuals with each genotype. You can then use the following formula:

p: frequency of the dominant allele (B)
q: frequency of the recessive allele (b)

Q: What is the Hardy-Weinberg principle?

A: The Hardy-Weinberg principle states that the frequencies of alleles in a population will remain constant from one generation to the next, assuming that the population is large and there is no selection, mutation, or genetic drift.

Q: What is the significance of the Hardy-Weinberg principle?

A: The Hardy-Weinberg principle is important because it provides a mathematical framework for understanding the evolution of populations. It also helps us to predict the frequencies of alleles in a population.

Q: How do you calculate the phenotype frequencies in a population?

A: To calculate the phenotype frequencies, you need to know the genotype frequencies. You can then use the following formula:

Phenotype frequency: number of individuals with a particular phenotype / total number of individuals

Q: What is the difference between a genotype and a phenotype?

A: A genotype is the genetic makeup of an individual, while a phenotype is the physical characteristics of an individual.

Q: How do you determine the genotype of an individual?

A: To determine the genotype of an individual, you need to know the genotype frequencies in the population. You can then use the following formula:

Genotype: genotype frequency x number of individuals with that genotype

Q: What is the significance of understanding dominant and recessive traits?

A: Understanding dominant and recessive traits is important because it helps us to understand the genetic mechanisms that underlie the distribution of traits in a population. It also helps us to predict the frequencies of alleles in a population.

Q: How do you apply the concept of dominant and recessive traits in real-life situations?

A: The concept of dominant and recessive traits is applied in many real-life situations, such as:

Genetic counseling: understanding the genetic mechanisms that underlie the distribution of traits in a population can help genetic counselors to provide accurate information to clients.
Breeding programs: understanding the genetic mechanisms that underlie the distribution of traits in a population can help breeders to select individuals with desirable traits.
Evolutionary biology: understanding the genetic mechanisms that underlie the distribution of traits in a population can help evolutionary biologists to understand the evolution of populations.

Q: What are some common examples of dominant and recessive traits?

A: Some common examples of dominant and recessive traits include:

Eye color: brown eye color is a dominant trait, while blue eye color is a recessive trait.
Hair color: black hair color is a dominant trait, while red hair color is a recessive trait.
Blood type: type A blood is a dominant trait, while type O blood is a recessive trait.

Q: How do you determine the genotype of an individual with a dominant trait?

A: To determine the genotype of an individual with a dominant trait, you need to know the genotype frequencies in the population. You can then use the following formula:

Genotype: genotype frequency x number of individuals with that genotype

Q: What is the significance of understanding the genotype of an individual with a dominant trait?

A: Understanding the genotype of an individual with a dominant trait is important because it helps us to understand the genetic mechanisms that underlie the distribution of traits in a population. It also helps us to predict the frequencies of alleles in a population.

Q: How do you apply the concept of dominant and recessive traits in genetic engineering?

A: The concept of dominant and recessive traits is applied in genetic engineering to create new traits in organisms. For example, scientists can use genetic engineering to create crops that are resistant to pests or diseases.

Q: What are some common applications of genetic engineering?

A: Some common applications of genetic engineering include:

Crop improvement: genetic engineering is used to create crops that are resistant to pests or diseases.
Animal breeding: genetic engineering is used to create animals with desirable traits.
Medical applications: genetic engineering is used to create new treatments for diseases.

Q: How do you determine the genotype of an individual with a recessive trait?

A: To determine the genotype of an individual with a recessive trait, you need to know the genotype frequencies in the population. You can then use the following formula:

Genotype: genotype frequency x number of individuals with that genotype

Q: What is the significance of understanding the genotype of an individual with a recessive trait?

A: Understanding the genotype of an individual with a recessive trait is important because it helps us to understand the genetic mechanisms that underlie the distribution of traits in a population. It also helps us to predict the frequencies of alleles in a population.

Q: How do you apply the concept of dominant and recessive traits in forensic science?

A: The concept of dominant and recessive traits is applied in forensic science to analyze DNA evidence. For example, scientists can use genetic engineering to create DNA profiles that can be used to identify individuals.

Q: What are some common applications of forensic science?

A: Some common applications of forensic science include:

Crime scene investigation: forensic scientists analyze DNA evidence to identify individuals.
DNA profiling: forensic scientists create DNA profiles that can be used to identify individuals.
Genetic genealogy: forensic scientists use genetic engineering to create DNA profiles that can be used to identify individuals.

Q: How do you determine the genotype of an individual with a mixed trait?

A: To determine the genotype of an individual with a mixed trait, you need to know the genotype frequencies in the population. You can then use the following formula:

Genotype: genotype frequency x number of individuals with that genotype

Q: What is the significance of understanding the genotype of an individual with a mixed trait?

A: Understanding the genotype of an individual with a mixed trait is important because it helps us to understand the genetic mechanisms that underlie the distribution of traits in a population. It also helps us to predict the frequencies of alleles in a population.

Q: How do you apply the concept of dominant and recessive traits in agriculture?

A: The concept of dominant and recessive traits is applied in agriculture to create crops that are resistant to pests or diseases. For example, scientists can use genetic engineering to create crops that are resistant to pests or diseases.

Q: What are some common applications of agriculture?

A: Some common applications of agriculture include:

Crop improvement: genetic engineering is used to create crops that are resistant to pests or diseases.
Animal breeding: genetic engineering is used to create animals with desirable traits.
Food production: genetic engineering is used to create crops that are more nutritious or have improved flavor.

Q: How do you determine the genotype of an individual with a complex trait?

A: To determine the genotype of an individual with a complex trait, you need to know the genotype frequencies in the population. You can then use the following formula:

Genotype: genotype frequency x number of individuals with that genotype

Q: What is the significance of understanding the genotype of an individual with a complex trait?

A: Understanding the genotype of an individual with a complex trait is important because it helps us to understand the genetic mechanisms that underlie the distribution of traits in a population. It also helps us to predict the frequencies of alleles in a population.

Q: How do you apply the concept of dominant and recessive traits in medicine?

A: The concept of dominant and recessive traits is applied in medicine to understand the genetic mechanisms that underlie the distribution of traits in a population. For example, scientists can use genetic engineering to create new treatments for diseases.

Q: What are some common applications of medicine?

A: Some common applications of medicine include:

Disease treatment: genetic engineering is used to create new treatments for diseases.
Genetic counseling: genetic counselors use genetic engineering to provide accurate information to clients.
Personalized medicine: genetic engineering is used to create personalized treatments for individuals.

Q: How do you determine the genotype of an individual with a rare trait?

A: To determine the genotype of an individual with a rare trait, you need to