Two pure lines obtained from Mendel's experiments are crossed to each other.The first line makes green smooth seeds (peas),and the second line has white flowers.All F₁individuals have purple flowers and produce yellow wrinkled seeds.What proportion of the F₂ plants should have purple flowers and make green wrinkled seeds?

Question

Quizplus · Accepted Answer

The traits mentioned are governed by two different genes, one for seed color and texture (green smooth vs. yellow wrinkled) and the other for flower color (white vs. purple). Mendel's law of independent assortment states that these genes will assort independently during gamete formation. Given that all F1 individuals have purple flowers and produce yellow wrinkled seeds, we can infer that purple flower color and yellow seed color are dominant traits, while green seed color and wrinkled seed texture are recessive. To get green wrinkled seeds with purple flowers in the F2 generation, we need a genotype that is heterozygous for flower color (Pp, where P=purple and p=white) and homozygous recessive for both seed color and texture (yyrr, where Y=yellow, y=green, R=smooth, and r=wrinkled). The probability of getting a Pp genotype is 1/2 (since one parent is PP and the other is pp), and the probability of getting a yyrr genotype is 1/4 (for yy, since one parent is YY and the other is yy) times 1/4 (for rr, since one parent is RR and the other is rr), which equals 1/16. Multiplying these probabilities together gives 1/2 * 1/16 = 1/32. However, since the question specifically asks for plants with purple flowers and green wrinkled seeds, and the calculation error in the explanation, the correct approach should consider the combination of traits directly from the cross, which involves calculating the probability of each trait separately and then combining them. For purple flowers (Pp) and green wrinkled seeds (yyrr), the correct calculation involves understanding the Mendelian ratios for each trait and combining them, which was not accurately reflected in the initial explanation. The correct proportion for purple flowers and green wrinkled seeds involves considering the independent assortment and dominance of traits, leading to a 3/64 chance when considering the correct Mendelian inheritance patterns for both flower color and seed traits.

Two Pure Lines Obtained from Mendel's Experiments Are Crossed to Each