7.1.1 Monohybrid Inheritance

• Mendel's Laws form the foundation of genetics and describe how traits are inherited


  True
• Dominant traits are expressed only when two copies of the corresponding allele are present

  False
• The RR genotype results in red flowers in pea plants


  True
• The phenotypic ratio in a cross between two heterozygous plants is 3 red flowers to 1 white flower
• The Law of Segregation ensures that offspring receive one allele from each parent


  True
• What are alleles?

  Different forms of a gene
• A dominant trait is expressed when only one copy of the corresponding allele is present in the genotype
• The Law of Segregation ensures that each parent contributes one allele
• Observable traits are referred to as the phenotype.


  True
• What is an example of a genotype?

  AA, Aa, aa
• In a monohybrid cross with two heterozygous parents (Rr), the phenotypic ratio is 3:1
• Order the steps in gamete formation according to Mendel's Law of Segregation.

  1️⃣ Allele pairs separate

  2️⃣ Each gamete receives one allele per trait
• Alleles are different forms of a gene that occupy the same genetic locus
• What is a trait expressed even when only one copy of the allele is present?

  Dominant trait
• In pea plants, if red flowers (R) are dominant over white flowers (r), what is the phenotype of a plant with genotype Rr?

  Red flowers
• In a cross between two heterozygous pea plants (Aa), the phenotypic ratio is 3:1
• In a Punnett square for two heterozygous pea plants (Aa), what is the phenotypic ratio if round seeds (A) are dominant over wrinkled seeds (a)?

  3 round to 1 wrinkled
• Each cell in a Punnett square represents a possible genotype for the offspring.


  True
• Monohybrid inheritance involves a single gene with two alleles
• Filling in a Punnett square involves combining parental alleles to show possible offspring genotypes.


  True
• Steps to construct a Punnett square

  1️⃣ List the parental alleles

  2️⃣ Combine the alleles to show genotypes

  3️⃣ Determine phenotypic ratios
• What does the term 'phenotype' refer to in genetics?

  Observable traits of an individual
• A Punnett square is used to predict the possible genotypes and phenotypes
• What is monohybrid inheritance?

  Single gene with two alleles
• Mendel's Law of Segregation states that allele pairs separate during gamete formation.


  True
• What does the Law of Independent Assortment state about the inheritance of traits?

  Traits are inherited independently
• Steps of gamete formation according to Mendel's Laws

  1️⃣ Allele pairs separate

  2️⃣ Each gamete receives one allele

  3️⃣ Genes for different traits assort independently
• What are the possible genotypes for flower color in pea plants if 'R' represents red and 'r' represents white?

  RR, Rr, rr
• In pea plants, red flowers (R) are dominant over white flowers (r). A plant with genotype Rr will have red flowers.


  True
• A Punnett square is used to predict the possible genotypes and phenotypes of offspring from a genetic cross.
• Monohybrid inheritance involves a single gene with two alleles.
• What do you list along the axes of a Punnett square if the parents have genotypes Aa?

  A and a
• In a cross between two heterozygous pea plants (Aa), the 'A' allele is dominant for round seeds, and 'a' is recessive for wrinkled seeds.


  True
• Monohybrid inheritance involves a single gene with two alleles
• What is the primary purpose of a Punnett square?

  Predict genotypes and phenotypes
• In a cross between two heterozygous pea plants (Aa), the possible genotypes are AA, Aa, and aa
• What is the phenotypic ratio for flower color in pea plants if red (R) is dominant over white (r)?

  3 red : 1 white
• The phenotypic ratio in a cross between two heterozygous pea plants (Rr) for flower color is 3 red flowers to 1 white flower
• The phenotypic ratio in a cross between two heterozygous pea plants (Rr) is 3 red flowers to 1 white flower
• What is the final step in solving monohybrid inheritance problems using Punnett squares?

  Calculate phenotypic ratio