Sources of genetic variation

• How do genetic mutations contribute to genetic variation?

  They create different versions of a trait
• What is a deletion mutation?

  Removing bases from the DNA sequence
• What are the two types of chromosomes shown in the image?

  • Paternal chromosome
  • Maternal chromosome
• What is the process shown in the image called?

  Crossing over
• What is the purpose of DNA replication shown in the image?

  • Ensures each daughter cell receives a complete set of genetic material during cell division
  • Allows for the accurate transmission of genetic information to the next generation
• What happens during the first division of meiosis?

  Pairs of chromosomes normally separate
• What can happen if chromosomes do not separate during meiosis?

  Some gametes may have too many or too few chromosomes
• What is meiosis?

  A special type of cell division
• What is the purpose of crossing over during meiosis?

  • Increases genetic diversity by shuffling alleles
  • Allows for recombination of genetic material
  • Helps create unique gametes
• What is a substitution mutation?

  Swapping one base for another
• What types of cells are produced by meiosis?

  Sperm or egg cells
• What is random fertilization?

  Random joining of sperm and egg cells
• What is the role of meiosis in genetic variation?

  It contributes to genetic diversity
• How do mutations, meiosis, and random fertilization work together?

  They create the diversity seen in living things
• What are genetic mutations?

  Changes to DNA that can alter genes
• What are the three main types of genetic mutations?

  • Substitution: Swapping one base for another
  • Insertion: Adding extra bases
  • Deletion: Removing bases
• How does random fertilization affect genetic diversity within a family?

  It showcases genetic diversity among siblings
• What are the key processes in meiosis that create genetic variation?

  • Separation of chromosome pairs
  • Random sorting of chromosomes into daughter cells
  • Potential errors in chromosome separation
• What is the purpose of crossing over during meiosis?

  To increase genetic diversity by shuffling alleles
• How does random fertilization contribute to genetic variation?

  It creates unique combinations of traits in offspring
• What is the first step in cell division?

  First division
• Why are the gametes not separated in the first division?

  They are not separated
• What might a substitution in the gene for eye color change?

  It might change eyes from brown to blue
• What is an insertion mutation?

  Adding extra bases to the DNA sequence
• How does crossing over contribute to genetic diversity?

  It allows for recombination of genetic material between homologous chromosomes
• What does the combination bb represent in terms of eye color?

  Children with brown eyes
• What is genetic variation?

  Diversity of genes within a population
• What happens in the second division of cell division?

  Second division
• What is the process of genetic recombination?

  It occurs through crossing over during meiosis I
• How does genetic recombination contribute to evolution?

  By increasing variation in a population
• How does the process of DNA replication shown in the image differ from DNA replication during mitosis?

  During meiosis, DNA replication occurs before the first cell division, whereas in mitosis it occurs before each cell division
• If a father has genes for blue eyes (B) and brown eyes (b), what combinations can his children inherit?

  BB, Bb, or bb
• How many gametes does meiosis create?

  Four different gametes
• What does genetic variation mean for individuals in a population?

  Individuals have different traits
• What happens during crossing over in meiosis I?

  Homologous chromosomes swap segments of DNA
• What are the sources of genetic variation?

  Inherited genes and random DNA changes
• What are the key differences between the first and second divisions of cell division?

  • First division: Chromosomes not separated
  • Second division: Chromosomes separated into two cells
• What is the primary purpose of crossing over during meiosis I?

  To create new combinations of parental DNA
• How do chromosomes behave during meiosis I?

  They line up and exchange segments physically
• What builds on what meiosis starts in terms of genetic variation?

  Crossing over creates new combinations of parental DNA