Genetics Overview Quiz

Genetics

• Genetics is the study of inheritance of traits.
• Heredity is the passing of traits from parents to offspring.
• A trait is a characteristic of an individual.
• A gene is a sequence of DNA that codes for a protein.
• An allele is a different version of a gene.
• Mitosis and meiosis are processes of cell division for genetic material separation.
• Meiosis involves two divisions (Meiosis I and Meiosis II).
• Crossing over occurs during prophase I of meiosis.
• Crossing over/recombination involves exchange of DNA segments between homologous chromosomes.
• Meiosis produces haploid gametes (sex cells).
• Phenotype is observable traits, e.g., eye color, hair color.
• Genotype is the genetic makeup of an organism (represented by alleles).
• Dominant allele determines phenotype in heterozygous individuals.
• Recessive allele determines phenotype only in homozygous individuals.
• Homozygous: having two identical alleles for a gene.
• Heterozygous: having two different alleles for a gene.
• Gregor Mendel is considered the father of genetics.
• Pea plants were used by Mendel in experiments due to their ease of manipulation, large numbers and low cost.
• Punnett squares are used to predict the outcome of crosses between individuals.
• Mendel's Law of Segregation: alleles of each gene separate during gamete formation.
• Dominant allele expresses its trait even in heterozygous individuals.
• Recessive allele expresses only when homozygous.
• Incomplete dominance: Heterozygous phenotype is a blend of homozygous parental phenotypes.
• Complete dominance: Dominant allele entirely masks recessive allele's effect.
• Monohybrid cross: examines inheritance of one trait
• Dihybrid cross: examines inheritance of two traits.
• Codominance: both alleles in a heterozygous individual are fully expressed (e.g., blood types).
• Multiple alleles: when three or more alleles for a gene exist in a population.
• Polygenic inheritance: multiple genes affect a single trait (e.g., height, skin color).
• Discrete traits: traits influenced by one gene and have distinct phenotypes.
• Species variation is differences in species, behavior, physical and genetic characteristics.

Species Variation and Adaptation

• Species is a group of organisms capable of interbreeding and producing fertile offspring.
• Species variation helps in adaptation.
• Genetic variation is influenced by the environment (e.g., food resources, predators, weather).
• Polygenic inheritance is an example of species variation (e.g., skin color).