Unit 5: Heredity Flashcards

Flashcards related to heredity, meiosis, genetics, and inheritance patterns based on a lecture transcript.

Prophase One

The first step of meiosis where chromatin condenses, sister chromatids and homologous pairs line up, and crossing over occurs.

Crossing Over

The exchange of genetic information between non-sister chromatids during prophase one of meiosis, leading to recombinant chromosomes.

Recombinant Chromosomes

Chromosomes that are a combination of genetic information from both parents due to crossing over during meiosis.

Metaphase One

The stage of meiosis where homologous chromosomes align on the metaphase plate, and independent assortment occurs.

Independent Assortment

The random alignment of maternal and paternal chromosomes during metaphase one of meiosis, allowing for genetic variety in gametes.

Anaphase One

The phase of meiosis where homologous chromosomes move to opposite poles of the cell.

Haploid

Cells with half the number of chromosomes as a diploid cell, produced at the end of meiosis one.

Meiosis Two

The second division in meiosis where sister chromatids line up, separate, and result in four haploid cells.

Mitosis

Cell division that results in two identical diploid daughter cells.

Meiosis

Cell division that results in four genetically distinct haploid daughter cells.

Complete Dominance

A type of inheritance where the dominant trait completely masks the recessive trait.

Co-dominance

A type of inheritance where both traits are expressed independently of each other in a heterozygous individual.

Incomplete Dominance

A type of inheritance where the heterozygous condition results in a blend of the two traits.

Monohybrid

A cross involving organisms that are heterozygous for one trait.

Dihybrid

A cross involving organisms that are heterozygous for two traits.

Autosomal Inheritance

Inheritance of genes located on non-sex chromosomes (autosomes).

Sex-linked Inheritance

Inheritance of genes located on sex chromosomes (e.g., X or Y chromosome).

Maternal Inheritance

Inheritance of DNA found in mitochondria or chloroplasts, typically inherited from the mother.

Linked Genes

Genes located on the same chromosome that tend to be inherited together.

Law of Segregation

Homologous chromosomes separate and move to opposite poles during meiosis.

Law of Independent Assortment

Alleles for different traits are distributed independently during gamete formation.

Sickle Cell Disease

Genetic disorder where being homozygous recessive results in has sickle-shaped red blood cells.

Tay-Sachs Disease

Autosomal recessive disorder that affects proteins in the brain.

Huntington's Disease

Autosomal dominant neurodegenerative disease.

Down Syndrome

Genetic disorder characterized by having three copies of chromosome 21 (trisomy 21).

Klinefelter Syndrome

Genetic condition in males characterized by having an XXY chromosome.

Turner Syndrome

Genetic condition in females characterized by having only one X chromosome (XO).

Phenotypic Plasticity

The ability of an organism with a given genotype to exhibit different phenotypes in different environments.