Examples of Mendel's Law of Segregation in Pea Plants

📚 Quick Study Guide

• 🧬 Mendel's Law of Segregation: During gamete formation, allele pairs separate or segregate, and each gamete carries only one allele for each gene.
• 🌱 Pea Plant Traits: Mendel studied traits like flower color (purple or white), seed shape (round or wrinkled), and seed color (yellow or green).
• 🔑 Key Concepts:
  • Allele: A variant form of a gene.
  • Homozygous: Having two identical alleles for a trait (e.g., PP or pp).
  • Heterozygous: Having two different alleles for a trait (e.g., Pp).
  • Phenotype: The observable characteristic (e.g., purple flowers).
  • Genotype: The genetic makeup (e.g., PP, Pp, or pp).
• 🧮 Punnett Square: A diagram used to predict the genotypes and phenotypes of offspring from a genetic cross.
• 📝 Monohybrid Cross: A cross between individuals that involves one pair of contrasting traits.

🧪 Practice Quiz

1. Which of the following statements best describes Mendel's Law of Segregation?
   1. A. Alleles are always inherited together.
   2. B. Allele pairs separate during gamete formation.
   3. C. Dominant alleles are always expressed.
   4. D. Recessive alleles are always expressed.
2. In pea plants, purple flower color (P) is dominant to white flower color (p). What is the phenotype of a plant with the genotype Pp?
   1. A. White
   2. B. Purple
   3. C. Pink
   4. D. A mix of purple and white
3. A pea plant heterozygous for seed shape (Rr, where R = round and r = wrinkled) is crossed with a homozygous recessive plant (rr). What percentage of the offspring are expected to have wrinkled seeds?
   1. A. 0%
   2. B. 25%
   3. C. 50%
   4. D. 75%
4. Which of the following represents a homozygous dominant genotype for seed color in pea plants, where Y = yellow and y = green?
   1. A. Yy
   2. B. yy
   3. C. YY
   4. D. None of the above
5. During which process does the segregation of alleles occur?
   1. A. Mitosis
   2. B. Fertilization
   3. C. Meiosis
   4. D. Transcription
6. If two pea plants with the genotype Yy are crossed, what is the probability of producing offspring with the genotype yy? (Y = yellow, y = green)
   1. A. 25%
   2. B. 50%
   3. C. 75%
   4. D. 100%
7. In a monohybrid cross involving seed shape (R = round, r = wrinkled), all offspring display a round phenotype. What are the possible genotypes of the parents?
   1. A. RR x rr
   2. B. Rr x Rr
   3. C. rr x rr
   4. D. RR x RR or RR x Rr