Question

4. In a particular plant, long stem is dominant over short stem. This same plant may produce red flowers

or white flowers with this trait showing incomplete dominance. Cross a heterozygous long stemmed
pink plant with a heterozygous long stemmed red flowering plant.
Genotype of the heterozygous long-stemmed pink
Genotype of the heterozygous long-stemmed red
Ma
probability of getting a long-stemmed offspring?
probability of getting a white plant offspring?

Answer 1

The genotypes of the heterozygous long-stemmed pink and heterozygous long-stemmed red plants can be represented as follows:

Heterozygous long-stemmed pink plant: LlWw

Heterozygous long-stemmed red plant: LlRr

where L represents the dominant allele for long stem, l represents the recessive allele for short stem, W represents the recessive allele for white flowers, and R represents the dominant allele for red flowers with incomplete dominance.

To determine the probability of getting a long-stemmed offspring, we need to consider the possible genotypes of the offspring. These can be determined by multiplying the alleles from each parent:

Gametes from LlWw plant: LW, Lw, lW, lw

Gametes from LlRr plant: LR, Lr, lR, lr

The possible genotypes of the offspring from this cross and their probabilities can be represented as follows:

LLWw: 1/8

LlWw: 2/8

LlRr: 2/8

LLRr: 1/8

LWRr: 1/8

lwWw: 1/8

Therefore, the probability of getting a long-stemmed offspring (either LLWw, LlWw, or LlRr) is:

P(long stem) = P(LLWw) + P(LlWw) + P(LlRr) = 1/8 + 2/8 + 2/8 = 5/8 or 0.625

To determine the probability of getting a white plant offspring, we need to consider the possible genotypes of the offspring that would result in a white flower. In this case, the only possible genotype that would produce a white plant is the homozygous recessive genotype for the flower color (ww). Therefore, the probability of getting a white plant offspring is:

P(white flower) = P(LLWw) + P(lwWw) = 1/8 + 1/8 = 1/4 or 0.25

Step-by-step explanation: