Genes and alleles

• What are the properties that differentiate genes from alleles?

  • Gene: A segment of DNA coding for a specific protein
  • Allele: Different forms of the same gene
  • Purpose of Gene: Builds a specific protein
  • Purpose of Allele: Determines variations in a trait
  • Location: Genes are on chromosomes; alleles are at the same locus on chromosomes
• What are genes often compared to in the study material?

  Tiny instruction manuals
• How do alleles differ from each other?

  They code for variations of the same trait
• What do genes detail according to the study material?

  How to build specific proteins
• What do the ratios in a Punnett square indicate?

  Probability of each possible combination
• How can alleles be compared to books in a library?

  Alleles are like different editions of the same book
• How can a gene be compared to a recipe?

  It contains instructions for building a specific protein
• What do genes determine in offspring?

  Hereditary traits like eye color
• If one allele codes for brown eyes, what might another allele code for?

  Blue eyes
• What is the difference between dominant and recessive alleles?

  • Dominant alleles are represented by uppercase letters (e.g. B)
  • Recessive alleles are represented by lowercase letters (e.g. b)
  • Dominant alleles are expressed even if only one copy is present (Bb)
  • Recessive alleles are only expressed if two copies are present (bb)
• What is a gene?

  A segment of DNA coding for a specific protein
• What does heterozygous mean in genetics?

  Having different alleles for a gene pair
• What are the genotypes and phenotypes for homozygous individuals?

  • Homozygous Dominant:
  • Genotype: BB
  • Phenotype: Brown eyes
  • Homozygous Recessive:
  • Genotype: bb
  • Phenotype: Blue eyes
• When does a trait appear in homozygous recessive individuals?

  When both alleles are recessive
• What do dominant alleles do to recessive alleles?

  Mask their expression
• What genotype is homozygous recessive?

  bb
• How is DNA described in relation to genes?

  As the entire library containing genes
• What is the phenotype of a heterozygous genotype (Bb)?

  Only the dominant allele's trait shows
• How does the function of a gene differ from that of an allele?

  Genes provide blueprints; alleles produce phenotypes
• What does homozygous mean in genetics?

  Having identical alleles for a gene pair
• What are alleles?

  Different versions of a gene
• What are the properties of genes as outlined in the study material?

  • Purpose: Contains instructions to build specific proteins
  • Location: Found within DNA
  • Function: Determines hereditary traits
• How can you determine the phenotype of an individual based on their genotype?

  • If the individual is homozygous dominant (BB), they will have the dominant phenotype
  • If the individual is heterozygous (Bb), they will also have the dominant phenotype
  • If the individual is homozygous recessive (bb), they will have the recessive phenotype
• What are the two types of alleles shown in the image?

  Dominant and recessive
• What are the genotypes of the homozygous and heterozygous individuals shown in the image?

  Homozygous: bb, Heterozygous: Bb
• How do heterozygous and homozygous genotypes affect phenotypes?

  Heterozygous shows dominant traits, homozygous shows specific traits
• What is the relationship between genotype and phenotype in heterozygous individuals?

  • Genotype: Bb
  • Phenotype: Brown eyes (B is dominant over b)
• What do alleles code for?

  Different versions of the same trait
• What is the purpose of a Punnett square?

  • Predict offspring genotypes
  • Predict offspring phenotypes
  • Based on parental alleles
• What is the relationship between the dominant and recessive alleles shown in the image?

  Dominant alleles are represented by uppercase letters, while recessive alleles are represented by lowercase letters