2. You Are Working With Pea Plants And Found 36 Plants Out Of 400 Were Dwarf.Data: Frequency Of Recessive Phenotype (36 Out Of 400).(a) Calculate The Frequency Of The Tall Gene.(b) Determine The Number Of Heterozygous Pea Plants.---3. In Humans, The
Understanding the Genetics of Pea Plants: A Study on Dwarf Phenotype
In the world of genetics, pea plants have been a popular subject for studying the principles of inheritance. The work of Gregor Mendel, an Austrian monk, laid the foundation for modern genetics by conducting experiments on pea plants. In this article, we will delve into a specific scenario where 36 out of 400 pea plants exhibit a dwarf phenotype. We will calculate the frequency of the tall gene and determine the number of heterozygous pea plants.
Pea plants exhibit a simple Mendelian trait, where the height of the plant is determined by a single gene with two alleles: T (tall) and t (dwarf). The T allele is dominant, while the t allele is recessive. This means that a pea plant with the genotype TT or Tt will be tall, while a plant with the genotype tt will be dwarf.
Calculating the Frequency of the Tall Gene
To calculate the frequency of the tall gene, we need to first determine the number of pea plants that are homozygous dominant (TT) and heterozygous (Tt). Since 36 out of 400 pea plants are dwarf, we can assume that the remaining 364 plants are tall.
Let's denote the frequency of the tall gene as p. Since the frequency of the recessive allele is q, we can write the following equation:
p + q = 1
We know that the frequency of the recessive allele is q = 36/400 = 0.09. Therefore, we can calculate the frequency of the tall gene as follows:
p = 1 - q = 1 - 0.09 = 0.91
So, the frequency of the tall gene is approximately 0.91 or 91%.
Determining the Number of Heterozygous Pea Plants
To determine the number of heterozygous pea plants, we need to use the Hardy-Weinberg principle, which states that the frequency of alleles in a population remains constant from generation to generation in the absence of other evolutionary influences. We can use the following equation to calculate the frequency of heterozygous individuals:
p^2 + 2pq + q^2 = 1
where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and p^2, 2pq, and q^2 represent the frequencies of homozygous dominant, heterozygous, and homozygous recessive individuals, respectively.
We know that p = 0.91 and q = 0.09. Plugging these values into the equation, we get:
(0.91)^2 + 2(0.91)(0.09) + (0.09)^2 = 1
Simplifying the equation, we get:
0.8281 + 0.1638 + 0.0081 = 1
Therefore, the frequency of heterozygous individuals is:
2(0.91)(0.09) = 0.1638
To determine the number of heterozygous pea plants, we can multiply the frequency of heterozygous individuals by the total number of pea plants:
0.1638 x 400 = 65.52
Since we cannot have a fraction of a plant, we can round down to the nearest whole number. Therefore, there are approximately 65 heterozygous pea plants.
In this article, we calculated the frequency of the tall gene in a population of pea plants and determined the number of heterozygous pea plants. We used the Hardy-Weinberg principle to calculate the frequency of heterozygous individuals and then multiplied this frequency by the total number of pea plants to determine the number of heterozygous plants. This study demonstrates the importance of understanding the genetics of pea plants and how it can be applied to real-world scenarios.
Frequently Asked Questions: Understanding the Genetics of Pea Plants
In our previous article, we explored the genetics of pea plants and calculated the frequency of the tall gene and the number of heterozygous pea plants. In this article, we will address some of the most frequently asked questions related to the genetics of pea plants.
Q: What is the difference between a dominant and a recessive allele?
A: In genetics, an allele is a variant of a gene that occupies a specific location on a chromosome. 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.
Q: How do you determine the genotype of a pea plant?
A: To determine the genotype of a pea plant, you need to know the phenotype of the plant. If the plant is tall, it can be either homozygous dominant (TT) or heterozygous (Tt). If the plant is dwarf, it must be homozygous recessive (tt).
Q: What is the Hardy-Weinberg principle?
A: The Hardy-Weinberg principle states that the frequency of alleles in a population remains constant from generation to generation in the absence of other evolutionary influences. This principle is used to calculate the frequency of heterozygous individuals in a population.
Q: How do you calculate the frequency of heterozygous individuals?
A: To calculate the frequency of heterozygous individuals, you need to use the Hardy-Weinberg principle. The equation is:
p^2 + 2pq + q^2 = 1
where p is the frequency of the dominant allele, q is the frequency of the recessive allele, and p^2, 2pq, and q^2 represent the frequencies of homozygous dominant, heterozygous, and homozygous recessive individuals, respectively.
Q: What is the significance of the frequency of heterozygous individuals?
A: The frequency of heterozygous individuals is important because it can affect the genetic diversity of a population. A high frequency of heterozygous individuals can lead to a more diverse population, while a low frequency can lead to a less diverse population.
Q: How do you determine the number of heterozygous pea plants?
A: To determine the number of heterozygous pea plants, you need to multiply the frequency of heterozygous individuals by the total number of pea plants.
Q: What is the relationship between the frequency of the tall gene and the number of heterozygous pea plants?
A: The frequency of the tall gene and the number of heterozygous pea plants are related because the frequency of the tall gene determines the frequency of heterozygous individuals. If the frequency of the tall gene is high, the frequency of heterozygous individuals will also be high.
In this article, we addressed some of the most frequently asked questions related to the genetics of pea plants. We hope that this article has provided a better understanding of the genetics of pea plants and how it can be applied to real-world scenarios.