Genetics and Evolution Quiz

Study Notes

Law of Segregation is observed in Meiosis 1 through the separation of homologous chromosomes, ensuring each gamete receives one allele per gene.
Law of Independent Assortment occurs during Metaphase 1, where random alignment of chromosome pairs leads to independent segregation of alleles from different genes.
These mechanisms significantly enhance genetic diversity in offspring.

Hox genes regulate the physical development of many animals and play a crucial role in morphology.
Homeotic Transformation occurs when removal of a gene in Drosophila produces altered morphological traits.
Functional Redundancy explains why deletion of the hoxA3 gene in mice has no phenotype effect, as other Hox genes can compensate.

Functional Complementation occurs when different alleles provide distinct functions beneficial for survival.
Improved Protein Function results from allelic diversity that enhances overall protein effectiveness.
Resistance to Pathogens is achieved through diverse immune responses enabled by heterozygosity, leading to greater adaptability.

Primary Structure: Sequence of nucleotides in a strand.
Secondary Structure: Localized folding patterns like hairpins or loops.
Tertiary Structure: Three-dimensional conformation of a single nucleic acid molecule.
Quaternary Structure: Interactions between multiple nucleic acid molecules or with proteins.

Prokaryotic Chromosomes: Simpler, smaller, and typically consist of a single circular chromosome.
Eukaryotic Chromosomes: Complex, linear structures associated with histone proteins, found within a nucleus.

Heterozygous cats express decreased tail length due to a recessive allele, which is lethal in homozygous individuals.
Frequencies of offspring's phenotypes and genotypes can be calculated based on Mendelian inheritance principles.

Meiosis 1: Separates homologous chromosomes, halving the chromosome number.
Meiosis 2: Separates sister chromatids within existing daughter cells, resulting in four haploid gametes.

Transcriptional Control: Regulation of gene expression at transcription.
RNA Processing: Modifying RNA transcripts before translation.
Alternative Splicing: Creating diverse mRNA molecules from a single gene.
Epigenetic Modifications: Chemical changes affecting gene activity without altering DNA sequence.
Chromatin Structure: Organization of DNA and histones affecting accessibility for transcription.
Cell Division: Mechanisms ensuring proper distribution of chromosomes during cell division.

Gene: Specific DNA sequence coding for a trait.
Locus: Location on a chromosome where a gene resides.
Allele: Variants of a gene at a given locus; influences genotype and resultant phenotype.
Genotype: Combination of alleles determining traits; linked to phenotype.
Phenotype: Observable characteristics influenced by genotype.
Karyotype: Complete set of chromosomes in an organism; useful for identifying genetic abnormalities.