About This Chapter
Genetic Variability and Mutation - Chapter Summary
Gene mutations and genetic variability are central concepts in the study of evolution and adaptation, as well as being critical to our understanding of various gene-related illnesses and disorders. This comprehensive examination of genetic variation dives into the myriad ways genes are modified, deleted, and rearranged, producing the great diversity we observe throughout biological science. Our chapter covers the following concepts:
- Genetic variation through meiosis and fertilization
- Chromosomes: inheritance, sex determination, mutation, and rearrangements
- Mutagens and environmental effects on mutation rates
- Mutations: frameshift mutations and the effect of mutations, insertions, and deletions on protein function and DNA
- Cancer syndromes and genetic risk factors
- Genetic variability, random mutation, and genetic drift
- Inborn errors of metabolism
- Synapsis and meiosis/mitosis crossing over
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1. How Meiosis & Fertilization Promote Genetic Variation
Individuals are different because of their genetic variation. Even two siblings who come from the same parents have different genetic make-ups. This variation comes from both meiosis and fertilization, which are components of sexual reproduction.
2. The Chromosome Theory of Inheritance: Segregation and Independent Assortment
Mendel proposed the law of segregation and the law of independent assortment to explain the inheritance behind his pea plant traits. A hundred years later, Boveri and Sutton developed the chromosome theory of inheritance, which stated that chromosomes were responsible for the heredity Mendel observed. Learn about these men and their ideas in this lesson.
3. Sex Determination, X-Inactivation, and Barr Bodies
Sex determination, X-inactivation and Barr bodies are complex chromosomal processes. Learn more about each of these processes and test your knowledge with a quiz.
4. Cytoplasmic & Mitochondrial Inheritance: Types & Impacts
Everyone knows that you inherit genetic information from your parents, but did you know there are multiple ways for this to occur? In this lesson, we'll look at extranuclear inheritance and see what this means for passing on DNA.
5. Mutagens: How the Environment Affects Mutation Rates
What causes mutations to occur in living things? How do we avoid mutations? Are mutations always bad? Discover answers to these questions and more in this lesson on mutagens.
6. Effects of Frameshift Mutations: Definitions and Examples
What is a frameshift in genetic translation? How can a frameshift mutation change a protein? In this lesson, learn about the codon reading frame and how frameshift mutations cause serious problems for polypeptide formation.
7. Effects of Mutations on Protein Function: Missense, Nonsense, and Silent Mutations
How does a tiny point mutation change the way a protein works? What are the consequences of base substitutions? In this lesson, we'll use an imaginary creature to explore missense, nonsense and silent mutations.
8. What is a Point Mutation? - Definition, Causes & Types
What are genetic mutations? How do they affect our DNA? This lesson covers the basics of point mutations and provides simple examples of different mutation types.
9. Cancer Syndromes & Genetic Risk Factors for Cancer
This lesson describes something called cancer syndrome or family cancer syndrome, as well as the important clues that can help it be detected and two examples of such a condition.
10. Chromosomal Rearrangement
Have you ever switched out one thing for another or traded places with someone? Our chromosomes can do this, too. This lesson tells you how as we go over chromosomal rearrangements!
11. Genetic Variability and Random Mutation
Evolution is driven by variation among populations. The amount of variability determines how well a population can adapt to environmental changes, while random mutations can provide new variations that help a population adapt to unexpected changes.
12. What Are Inborn Errors of Metabolism?
Inborn errors of metabolism are genetic disorders that affect the metabolism of food components. Many of these disorders are difficult to diagnose but must be caught early in order to be treated. Learn about a common disorder, phenylketonuria.
13. Genetic Drift: Definition, Examples & Types
Genetic drift reduces genetic variability of a population by decreasing the size of the population. The change in population size and variability often leads to new species and unique populations.
14. Synapsis & Crossing Over in Meiosis
This lesson will cover synapsis and crossing over that occur during the process of meiosis. We'll look at exactly when these occur and how they can lead to greater genetic diversity.
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Other chapters within the MCAT Test: Practice and Study Guide course
- Introduction to Organic Chemistry
- Enzymes and Metabolism
- The Transcription and Translation Process
- The Molecular & Chromosomal Basis of Inheritance
- Genetic Variation, Control & Reproduction
- Developmental Mechanisms
- Mendelian Concepts
- Analytic Methods in Genetics
- Evolution & Natural Selection
- Development of Vertebrates
- Thermochemistry & Thermodynamics
- Glycolysis, Gluconeogenesis & Metabolic Regulation
- Kinetics and Equilibrium
- Cell Structure, Functions & Processes
- Virus Structure & Life Cycle
- Prokaryotic Cells
- Cell Biology & Cell Cycle
- Nerve, Muscle & Specialized Cell Types
- Endocrine System: Hormones & Mechanisms of Hormone Action
- Nervous System: Structure, Function & Sensory Reception
- Circulatory System Overview
- Lymphatic System
- Immune System: Innate and Adaptive Systems
- Digestive System Functions & Organs
- Urinary Systems & Structures
- Muscle and Skeletal Systems
- Respiratory System
- Skin System
- Human Reproductive Systems
- Reproductive Sequence
- Translational Motion
- Force, Motion & Gravitation
- Equilibrium and Momentum
- Work and Energy
- Principles of Fluids
- Gas Laws
- Electrostatics & Magnetism
- Electronic Circuit Elements
- Light & Geometrical Optics
- Atomic Structure and Components
- Atomic Nucleus
- Electronic Structure
- Trends of the Periodic Table
- Stoichiometric Calculations
- Acids and Bases Overview
- Solution Chemistry
- Molecular Bonding
- Phase Equilibria
- Basic Molecular Biology Laboratory Techniques
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- Human Senses
- Human Attention & Cognition
- States of Human Consciousness
- Characterizing Language Development
- Genetics, Evolution & Environmental Influences on Behavior
- Prenatal Development & Birth
- Principles of Motor Development, Learning & Control
- Development in the Adolescence Years
- Personality Components & Assessment
- Psychological Health & Disorders
- Motivation Types and Sources
- Attitude Types and Theories
- Types of Social Groups & Organizations
- Theories of Deviance & Social Control
- Learning and Conditioning
- Understanding the Self
- Prejudice & Discrimination
- Social Behavior
- Social Structure
- Families, Religions & Schools as Social Institutions
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