autosomal linkage and dihybrid inheritance

• What is a dominant allele?

  An allele that is always expressed
• When are recessive alleles expressed?

  When no dominant allele is present
• What does genotype refer to?

  The genetic composition of an organism
• What is phenotype?

  The characteristic due to genotype and environment
• What is a gene?

  A small section of DNA coding for a polypeptide
• What are alleles?

  Alternative forms of one gene
• What is a dihybrid cross?

  • Inheritance of two genes
  • Analyzed within the same Punnett square
• What is Mendelian genetics?

  The study of inheritance patterns in peas
• What does homozygous mean?

  Having two identical alleles for a gene
• What is the significance of the gametes in a genetic cross?

  They determine the offspring's genotypes
• What is the expected outcome when crossing a homozygous dominant with a homozygous recessive parent?

  All offspring will be heterozygous
• What does F1 represent in genetics?

  The first generation of offspring
• What happens when two heterozygous parents are crossed?

  They produce multiple gamete combinations
• What is the expected phenotypic ratio in a dihybrid cross?

  • 9 round yellow
  • 3 round green
  • 3 wrinkled yellow
  • 1 wrinkled green
• What is the impact of crossing over in meiosis?

  It creates new combinations of alleles
• What is autosomal linkage?

  Two genes located on the same chromosome
• What chromosomes are considered autosomal?

  Chromosomes 1 to 22 in humans
• How does autosomal linkage affect inheritance?

  Alleles must be inherited together
• What happens to the expected gametes in autosomal linkage?

  Only specific combinations are produced
• What is the result of crossing over in linked genes?

  It can create new allele combinations
• What is the expected phenotypic ratio when genes are linked?

  3 yellow round to 1 wrinkled green
• Why are some phenotypes less common in linked genes?

  Crossing over occurs infrequently
• What are the key points of dihybrid inheritance and autosomal linkage?

  • Dihybrid inheritance involves two genes
  • Expected ratio is 9:3:3:1
  • Autosomal linkage means genes are on the same chromosome
  • Crossing over can change expected ratios