Heterozygous tall and red flowered pea plants were selfed and total 2000 seeds are collected. What is the total number of seeds for both heterozygous traits?
500
To determine the total number of seeds for both heterozygous traits, we need to understand the principles of Mendelian genetics and the patterns of inheritance for each trait.
In this scenario, we are dealing with two traits: height (tall or short) and flower color (red or another color). The plants we are considering are heterozygous for both traits, meaning they possess two different alleles (forms of the same gene) for each trait.
First, let's consider the inheritance of each trait separately:
1. Height: The height trait in pea plants is governed by a single gene with two alleles: T for tall and t for short. The T allele (dominant) determines tall height, and the t allele (recessive) determines short height. In our scenario, the plants are heterozygous for height, which means they possess one T allele and one t allele (Tt).
2. Flower color: The flower color trait in pea plants is also governed by a single gene with two alleles: R for red and r for another color. The R allele (dominant) determines red flower color, and the r allele (recessive) determines the other color. In our scenario, the plants are heterozygous for flower color, which means they possess one R allele and one r allele (Rr).
Now, using the principles of Mendelian genetics, we can determine the possible combinations of alleles for both traits when the heterozygous plants self-fertilize. This can be done using a Punnett square:
T t
----------------
R | TR | Tr |
r | rT | rt |
---------------
In the Punnett square above, each cell represents a potential combination of alleles resulting from the self-fertilization of the heterozygous plants for both height and flower color.
From the square, we can see that there are four possible combinations of alleles: TR, Tr, rT, and rt.
Now, since the question states that a total of 2000 seeds were collected, we assume that each combination of alleles has an equal chance of occurring. Therefore, to find the total number of seeds for plants exhibiting both heterozygous traits, we need to determine the proportion of seeds for each combination and add them up.
Based on the Punnett square, we can see that each combination listed above has a 1/4 chance of occurring. Therefore, we can calculate the total number of seeds for heterozygous plants as follows:
Total number of seeds = Number of seeds for TR + Number of seeds for Tr + Number of seeds for rT + Number of seeds for rt
Since each combination has an equal probability of occurring, the number of seeds for each combination will be the same. Hence, we can simplify the equation to:
Total number of seeds = 4 * Number of seeds for any one combination
Given that the total number of seeds is 2000, we divide this number by 4 to find the number of seeds for any one combination:
Number of seeds for any one combination = Total number of seeds / 4 = 2000 / 4 = 500
Thus, the total number of seeds for both heterozygous traits (heterozygous tall and red flowered pea plants) is 500 seeds.