6.1.4 Genetic Inheritance

• Different versions of a gene are called alleles
• Stages of DNA replication

  1️⃣ Initiation

  2️⃣ Elongation

  3️⃣ Termination
• Match the enzyme with its function in DNA replication:

  Helicase ↔️ Unwinds DNA double helix

  DNA Polymerase ↔️ Adds nucleotides to growing DNA strands

  Primase ↔️ Synthesizes RNA primers

  Ligase ↔️ Joins DNA fragments together
• The combination of alleles an individual possesses is called their genotype
• What is the definition of genetic inheritance?

  Passing hereditary information
• What are genes located on in the cell?

  Chromosomes
• Genes determine traits by encoding proteins.

  True
• DNA replication begins at specific origins of replication along the DNA molecule.
• Which enzyme unwinds the DNA double helix during replication?

  Helicase
• Proofreading during DNA replication ensures accuracy by correcting errors with mismatch repair systems.
• Genetic inheritance is the process where hereditary information is passed from parents to offspring
• Genes are located on chromosomes and are responsible for determining traits.


  True
• During DNA replication, DNA polymerase adds nucleotides
• What are three possible alleles for eye color in humans?

  Blue, green, brown
• A person with the genotype Bb for eye color will have brown eyes because brown is dominant over blue.


  True
• Different versions of a gene are called alleles
• Genes are located on chromosomes
• Where are chromosomes found within a cell?

  Nucleus
• DNA replication results in two identical DNA molecules.


  True
• Each individual inherits two alleles for each gene, one from each parent.


  True
• An individual with two identical alleles for a trait is called homozygous
• What is the genotype for someone with blue eyes if blue is a recessive trait?

  bb
• What happens to the recessive allele when paired with a dominant allele?

  It is not expressed
• Recessive traits are expressed when an individual inherits two recessive alleles


  True
• Match the term with its definition:

  Allele ↔️ Different versions of a gene

  Genotype ↔️ Combination of alleles
• How many alleles does an individual inherit for each gene?

  Two
• What is the primary role of chromosomes?

  Carry hereditary information
• DNA polymerase uses the original DNA strands as templates to synthesize new complementary strands.
• Which enzyme synthesizes RNA primers during DNA replication?

  Primase
• Where does DNA replication begin on the DNA molecule?

  Origins of replication
• What happens during the termination stage of DNA replication?

  Replication forks meet
• Accuracy in DNA replication is ensured by proofreading and mismatch repair systems
• Dominant alleles mask the effect of recessive alleles when present.

  True
• What is the difference between genotype and phenotype?

  Genotype is allele combination, phenotype is observable trait
• In a heterozygous genotype, the dominant allele will mask the effect of the recessive allele.


  True
• Under what conditions is a recessive allele expressed in an individual?

  No dominant allele present
• What is the expected phenotype ratio in a Punnett square cross between a homozygous dominant (BB) and a homozygous recessive (bb) parent?

  3:1 for dominant to recessive
• The possible gametes from a homozygous dominant parent (BB) are only B
• Steps to use a Punnett square

  1️⃣ Identify the genotypes of the parents

  2️⃣ Create a 2x2 grid

  3️⃣ Write the possible gametes from each parent

  4️⃣ Combine the gametes to fill the grid
• A genotype refers to the combination of alleles