Genetics and Mendel's Laws of Inheritance

Practice vocabulary flashcards covering basic genetic concepts, chromosome structure, Mendelian inheritance, and meiosis from the Chapter 10 lecture.

Gregor Mendel

A nineteenth-century monastery priest who used the scientific method on plants to uncover the basic laws of inheritance, earning him the title of the father of genetics.

Gene

The nucleotide sequence of DNA that encodes for proteins.

Genome

The entire genetic makeup of an organism, comprising approximately $25{,}000$ genes in humans.

Chromosome

A structure found in the nucleus consisting of long strands of DNA wrapped around histone proteins; humans have a total of $46$ ($23$ from each parent).

Diploid Cell

A cell that contains paired homologous chromosomes, such as the fertilized egg cell formed after fertilization.

Allele

Different versions of the same gene.

Gene Locus

The specific physical location on a chromosome where a gene lives.

Sister Chromatids

The two identical copies that make up a single chromosome, each carrying a gene at the same locus.

Mutation

Any change in the nucleotide sequence of DNA that can alter a protein's function, with outcomes that may be harmful, helpful, or have no impact.

Wild Type

The original, unaltered gene sequence that yields a normal, functional protein.

Deletion

A specific type of mutation involving the removal of nucleotides (such as three nucleotides) from a DNA sequence, which can cause the resulting protein to be defective.

True Breeding

Plants that produce offspring identical to themselves when subjected to self-fertilization.

Hybrid

Plants that outwardly resemble true-breeding plants but carry mixed alleles and produce mixed offspring.

Dominant Allele

A version of a gene that is expressed even when only one copy is present in an individual's DNA, designated by a capital letter.

Recessive Allele

A version of a gene that is only expressed when an individual possesses two copies (one from each parent), designated by a lowercase letter.

Genotype

The underlying genetic makeup of an individual organism.

Phenotype

The observable physical appearance or outward expression of genetic information, such as seed color, height, skin color, and eye color.

Homozygous Dominant

A genotype consisting of two identical dominant alleles for a given gene, symbolized by two capital letters.

Heterozygous

A genotype consisting of one dominant allele and one recessive allele for a gene, symbolized by a capital letter paired with a lowercase letter.

Homozygous Recessive

A genotype consisting of two recessive alleles for a gene, symbolized by two lowercase letters, which results in the recessive phenotype.

Law of Segregation

Mendel's law stating that the two alleles of each gene separate or move apart during gamete formation in meiosis, distributing into different haploid cells.

Law of Independent Assortment

Mendel's law stating that chromosomes carrying different alleles are packaged and sorted into gametes independently of one another during meiosis.