Genetics Chapters 1-3 Flashcards

Green Revolution

• Transformed global food production in the 1950s and 60s.
• Norman Borlaug was a key leader in this movement.

Gene Therapy

• Involves direct gene alteration to address human diseases.

Evolution

• Refers to genetic changes over time.
• Comprises a two-step process: random inherited differences and their varying proportions in a population.

Developmental Biology

• Emphasizes the role of genetics in the development of tissues and organs through regulated gene expression.

Genome

• Represents a complete set of genetic information in nucleic acids (DNA or RNA).

Transmission/Classical Genetics

• Focuses on heredity principles and trait transmission between generations.
• Studies chromosome relations, gene arrangement, and gene mapping.

Molecular Genetics

• Examines the chemical nature of genes, including encoding, replication, and expression of genetic information.

Population Genetics

• Investigates genetic structures within populations and their changes over time and geography, essential for understanding evolution.

Model Genetic Organisms

• Ideal for genetic studies due to characteristics like short generation times, large offspring numbers, compact size, and low maintenance costs.
• Demonstrates universal genetic mechanisms across organisms.

Pangenesis

• An early theory suggesting that particles from the body inform reproductive cells, widely accepted until the 1800s.

Inheritance of Acquired Characteristics

• Proposes that traits acquired during an organism's life can be passed to offspring.

Historical Figures

• Robert Hooke discovered cells in 1665.
• Schleiden and Schwann proposed Cell Theory in 1839, emphasizing that all life is cellular.
• Walther Flemming observed mitosis in 1879.

Germ-Plasm Theory

• Developed by August Weismann, it posits that reproductive cells carry genetic information to offspring.

Prokaryotic Cells

• Characterized by lack of a nucleus, small size, circular DNA, and absence of organelles.
• Two categories: Archaea (with histone proteins) and Eubacteria (without histones).

Eukaryotic Cells

• Possess a nucleus, larger size, linear chromosomal DNA, and internal organelles.
• DNA is associated with histone proteins, forming chromatin.

Viruses

• Non-cellular entities with protein coats surrounding nucleic acids, requiring host cells for reproduction.

Cell Division

• Prokaryotes reproduce via binary fission.
• Eukaryotic cell division includes phases: G1, S (DNA synthesis), G2, M (mitosis).

Chromosomal Features

• Homologous chromosomes carry similar hereditary traits.
• Centromeres, telomeres, and origins of replication are essential for chromosome stability and division.

Cell Cycle Phases

• Interphase includes G1 (growth), S (DNA replication), G2 (preparation for mitosis), G0 (non-dividing).
• M phase encompasses mitosis and cytokinesis, critical for cell reproduction.

Meiosis

• Consists of two divisions: first reduces chromosome number, second is equational.
• Key stages: Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis, Anaphase I, Interkinesis, Prophase II, Metaphase II, Anaphase II.
• Handles genetic variation through crossing over and recombination.

Genetic Terms

• Gene: An inherited factor influencing traits.
• Alleles: Variants of a gene located at specific loci.
• Genotype: Genetic constitution, classified as homozygous (identical alleles) or heterozygous (different alleles).
• Phenotype: Observable expression of traits.

Mendelian Genetics

• F2 generation yields a 3:1 phenotypic ratio.
• Recessive alleles are masked by dominant alleles.
• Principles of Segregation and Independent Assortment govern allele transmission.

Genetic Crosses

• Backcross: Cross between F1 and parental genotype to demonstrate dominance.
• Testcross: Cross of unknown genotype with a homozygous recessive to determine genotype.

Dihybrid Cross

• Assesses two genetic traits with a standard ratio of 9:3:3:1 expected.

Molecular Genetics Insights

• Macromolecules include DNA and proteins, vital for heredity and cellular function.
• Richard Goldschmidt described the DNA structure as beads on a string.
• Thomas Hunt Morgan pioneered modern genetics using Drosophila fruit flies for studies.

Test your knowledge on key concepts from the first three chapters of genetics. This quiz covers important terms such as the Green Revolution, Gene Therapy, and Evolution. Perfect for students looking to reinforce their understanding of genetic principles.