Biology Chapter 8.22 - 8.23: Mutations Quiz

Roosevelt Quote

• "When you get to the end of your rope, tie a knot and hang on." - Franklin D. Roosevelt

Chapter 8.22 - 8.23: Mutations

• Learning Objectives:
  • Examples of lethal, harmful, and beneficial mutations
  • How traditional cell theory evolved into modern cell theory

Unit Organizer

• DNA is about the code of life
  • The code of life: DNA's role in making proteins
  • Structure of DNA: Shape and components
  • How DNA works: Historical experiments, structure with shape and components, replication for cell division, proteins made through transcription and translation

What is a Mutation?

• Any change in the order of the genetic code.

What is a Point Mutation?

• A mutation that affects one nucleotide.

Kinds of Mutations

• Gene Mutations
  • Involve a change in one or a few nucleotides
  • Known as point mutations because they occur at a single point in the DNA sequence
  • Include substitutions, insertions, and deletions
• Chromosomal Mutations
  • Involve changes in the number or structure of chromosomes
  • Include deletions, duplications, inversions, and translocations

Substitutions

• Usually affect no more than a single amino acid
• Example shown with TAC GCA TGG AAT DNA sequence

Insertions and Deletions

• Effects are more dramatic
• Result in frameshift mutations
• Occur when an addition or deletion of a nucleotide shifts the grouping of codons, causing entire codons to be read incorrectly

Insertion

• An extra base is inserted into a base sequence
• Example shown with a specific DNA sequence

Deletion

• The loss of a single base is deleted, and the reading frame is shifted
• Example shown with a specific DNA sequence

Chromosomal Mutations (Detail)

• Involve changes in the number or structure of chromosomes
• Include deletions, duplications, inversions, and translocations
• Examples of different chromosomal mutations (deletion, duplication, inversion, translocation) presented visually

Significance of Mutations

• Mutations are the ultimate source of new variation in species
• Many mutations have little or no effect on gene expression
• Some mutations cause genetic disorders or produce defective proteins (e.g., cancer)
• Mutations can happen randomly
• Source of genetic variability for species
• New genotypes and phenotypes
• Useful in new/changing environments
• Example of a randomly occurring mutation influencing the Scottish fold cat's ear shape

Polyploidy

• Errors in mitosis or meiosis can produce polyploid species
• Polyploidy involves having more than two chromosome sets
• Widely observed in plant species, but less frequent in animals

Significance of Plant Polyploidy

• Plants are regularly bred to have multiple sets of chromosomes
• Polyploid plants are often larger and stronger
• Examples include day lilies, bananas, and citrus fruits

Polyploidy in Vertebrates

• Polyploidy can occur in vertebrates, such as in frogs (rarely)

Inducing Mutations

• Scientists can increase genetic variation by inducing mutations
• Radiation and chemicals can be used to produce mutations
• Mutations can occur spontaneously

Mutation Examples

• Mutations produce new kinds of bacteria, such oil-eating bacteria used in bioremediation

Modern Cell Theory

• Energy flow (metabolism and biochemistry) occurs within cells
• Cells contain hereditary information (DNA) that is passed from cell to cell during cell division
• All cells are basically the same in chemical composition of similar species

History of Cell Study

• Cells were first named in 1665 by Robert Hooke.
• Schleiden, Schwann, and Virchow studied cells in the 1800s
• Now there is enough understanding to genetically engineer new combinations
• Future research is unknown

Section Review Questions

• Examples of lethal or harmful mutations
• Reasoning behind the expansion of the traditional cell theory into a modern cell theory

Test your knowledge on mutations in biological systems with this quiz covering types of mutations, their impacts, and how modern cell theory integrates these concepts. Dive into examples of lethal, harmful, and beneficial mutations and understand the fundamentals of DNA function in cellular processes.