Mendelian Genetics (2)

• What is a dihybrid cross?

  A dihybrid cross is a cross involving two pairs of contrasting traits.
• What are the dominant traits in the F1 offspring of a dihybrid cross?

  The F1 offspring will all be yellow and round.
• What does it indicate when yellow is dominant to green in a dihybrid cross?

  It indicates that yellow is the dominant trait over green.
• What is Mendel's fourth postulate regarding dihybrid crosses?

  Mendel proposed the postulate of independent assortment based on similar results in numerous dihybrid crosses.
• What happens during gamete formation according to the independent assortment postulate?

  During gamete formation, segregating pairs of unit factors assort independently of each other.
• How does the inheritance of one pair of characters relate to another in a dihybrid cross?

  The inheritance of one pair of characters is independent of the other pair.
• What does the postulate of independent assortment stipulate about segregation?

  The postulate stipulates that segregation of any pair of unit factors occurs independently of all others.
• What does each gamete receive during random segregation?

  Each gamete receives one member of every pair of unit factors.
• What does the law of segregation state?

  The law of segregation states that every individual possesses two alleles, and only one allele will be passed on to their offspring.
• What does the law of independent assortment state?

  The law of independent assortment states that the inheritance of one pair of genotypes is independent of the inheritance of the other pair.
• What does the postulate of independent assortment imply about gametes?

  It implies that all possible combinations of gametes are formed in equal frequency.
• How can a testcross be applied in genetics?

  A testcross can be applied to individuals that express two dominant traits but whose genotypes are unknown.
• What is a trihybrid cross?

  A trihybrid cross involves three pairs of contrasting traits.
• How many different gametes do F1 individuals produce in a trihybrid cross?

  Each F1 individual produces eight different gametes in equal frequencies.
• How many boxes would a Punnett square have for a trihybrid cross?

  A Punnett square for a trihybrid cross would have 64 separate boxes.
• What is the Forked-Line Method or Branch Diagram used for in genetics?

  • It is used to visualize the combinations of gametes.
  • Helps in calculating the probabilities of different genotypes and phenotypes.