Genetics Flashcards

Genetics Overview

• Genetics is the study of heredity, focusing on how traits are passed through generations.
• Heredity refers to the transmission of traits from parents to offspring.

Key Genetic Terminology

• A trait is a distinct characteristic that differs among individuals.
• Genes are DNA sequences that encode proteins, determining traits.
• The genome encompasses the full set of genetic instructions inherited by an organism.

Gregor Mendel and Genetic Principles

• Gregor Mendel, known as the father of genetics, established foundational principles of inheritance.
• Alleles are alternative forms of a gene, with dominant alleles represented by capital letters and recessive alleles by lowercase letters.

Genotype and Phenotype

• Genotype refers to an organism's genetic makeup, specifically the combination of alleles.
• Phenotype is the visible expression of the genotype, reflecting observable traits.

Genetic Composition

• Homozygous individuals have identical alleles for a trait, while heterozygous individuals possess different alleles.
• Punnett squares are tools used to predict genetic combinations in offspring from parental crosses.

Types of Genetic Crosses

• Monohybrid crosses focus on one trait, whereas dihybrid crosses examine two traits simultaneously.
• The P generation is the initial set of parents, yielding the F1 generation, which then produces the F2 generation through interbreeding.

Inheritance Patterns

• Purebred organisms are the result of mating similar parents; hybrids result from mating different types.
• The Principle of Dominance states that dominant traits will manifest in offspring when crossed with recessive traits.

Laws of Inheritance

• The Law of Segregation indicates that allele pairs separate during gamete formation.
• The Law of Independent Assortment suggests that different genes distribute independently during gamete production.

Non-Mendelian Inheritance

• Non-Mendelian inheritance patterns include incomplete dominance (blending of traits), codominance (both traits expressed), multiple alleles (traits governed by more than two alleles), polygenic traits (traits influenced by multiple genes), and sex-linked traits (traits determined by genes on sex chromosomes).

Genetic Tools and Concepts

• Pedigree charts track trait inheritance across generations.
• Chromatin is the unwound form of DNA, while chromosomes are condensed structures present during cell division.
• Chromatids are identical halves of a replicated chromosome.

Cell Division Processes

• Mitosis produces two identical cells, while meiosis produces four genetically varied cells, reducing chromosome number by half.
• Crossing over during meiosis enhances genetic variation through chromosome exchange.

Reproduction Types

• Sexual reproduction involves two parent cells merging, forming a zygote, while asexual reproduction involves a single parent replicating itself.

Genetic Variation and Mutations

• Genetic variation refers to differences among individuals in a species.
• Chromosomal mutations include deletions, duplications, inversions, and translocations, affecting chromosome structure or number.
• Nondisjunction is a common meiosis error, leading to conditions like trisomy (extra chromosome).

Genetic Engineering and Biotechnology

• DNA fingerprinting identifies unique DNA sequences; genetic engineering alters DNA in organisms.
• GMOs are organisms modified to contain genes from other species.
• Plasmids are circular DNA in bacteria, often used in recombinant DNA technology, which combines DNA from different sources.

Enzymatic and Biotechnological Applications

• Restriction enzymes cut DNA at specific sites, utilized in genetic engineering.
• Biotechnology applies living systems for product development and environmental solutions.
• Karyotypes visualize an organism's chromosome count and structure, aiding in genetic analysis.