STEM121 - General Biology 2 First Quarter Exam Flashcards

Comprehensive vocabulary flashcards covering Mendelian and Non-Mendelian genetics, pedigree analysis, the central dogma of molecular biology, and mutations.

Law of Dominance

A fundamental law stating that dominant alleles mask recessive ones in the $F1$ generation.

Law of Segregation

The law stating that alleles separate during gamete formation, allowing recessive traits to reappear in the $F2$ generation.

Law of Independent Assortment

The law that alleles of different genes distribute into gametes independently, often observed in dihybrid crosses.

Genotype

The specific allele combinations of an organism, such as $Tt$.

Phenotype

The observable traits of an organism, such as "tall".

Incomplete Dominance

An inheritance pattern where heterozygotes show an intermediate, blended phenotype.

Codominance

An inheritance pattern where both alleles are fully and simultaneously expressed, such as in Type $AB$ blood.

Multiple Alleles

A genetic system where more than two alleles exist for a trait, such as the $ABO$ Blood Group system.

X-linked recessive traits

Traits like red-green color blindness that are passed from carrier mothers to sons.

Epistasis

A phenomenon where one gene masks or modifies the expression of another gene.

Helicase

The enzyme responsible for unzipping the DNA double helix during replication.

DNA Polymerase

The enzyme responsible for the initiation and synthesis of new DNA strands.

DNA Ligase

An enzyme that joins Okazaki fragments together during DNA replication.

Telomerase

The enzyme that solves the end-replication problem in linear DNA.

Okazaki fragments

Short sequences of DNA nucleotides synthesized discontinuously on the lagging strand.

Transcription

The process of producing mRNA from a DNA template, occurring in the nucleus of eukaryotes.

Translation

The process of protein synthesis occurring in the cytoplasm, involving ribosomes and tRNA anticodons.

AUG

The specific start codon essential for the initiation of translation.

Substitution Mutation

A mutation where one base is swapped for another while the reading frame remains unchanged.

Frameshift Mutation

A mutation caused by the insertion or deletion of bases, shifting the reading frame for all downstream codons.

Nonsense Mutation

A mutation that creates a premature stop codon, resulting in a shortened, nonfunctional protein.

Neutral Mutation

A DNA change that does not alter the protein's overall function and has no effect on fitness, survival, or reproduction.

Monohybrid Phenotypic Ratio

The classic Mendelian ratio of $3:1$.

Dihybrid Phenotypic Ratio

The classic Mendelian ratio of $9:3:3:1$ for genes that assort independently.