MEIOSIS - BIO

Genetics and Inheritance

Meiosis I

The first stage of meiosis, where the chromosome number is halved through the separation of homologous chromosomes.

Meiosis II

The second stage of meiosis, which separates sister chromatids into four haploid cells.

Difference in Daughter Cells

Meiosis results in four daughter cells, while mitosis results in two daughter cells.

Crossing Over

A process occurring during meiosis where homologous chromosomes exchange genetic material, increasing genetic diversity.

Nondisjunction

An error in meiosis where chromosomes fail to separate properly, leading to genetic disorders.

Down Syndrome

A genetic disorder caused by trisomy of chromosome 21, characterized by developmental delays and physical features.

Turner Syndrome

A genetic disorder in females caused by a monosomy of the X chromosome (45,X), leading to various developmental and medical issues.

Klinefelter Syndrome

A genetic disorder in males caused by the presence of an extra X chromosome (47,XXY), leading to physical and reproductive issues.

Edward Syndrome

A genetic disorder caused by trisomy of chromosome 18, resulting in severe developmental problems.

Patau Syndrome

A genetic disorder caused by trisomy of chromosome 13, characterized by severe intellectual disability and physical abnormalities.

CRISPR Technology

A gene editing technology that can be used for precise modifications in the DNA sequence, raising ethical concerns in genetic modifications.

Blending Theory of Inheritance

An early theory that proposed offspring are a blend of parental traits, leading to uniformity in traits.

Limitations of Blending Theory

Blending theory fails to explain how traits can skip generations or how variations persist in populations.

Mendel's Contribution

Gregor Mendel's experiments on pea plants demonstrated that inheritance is determined by discrete units (genes), not blending.

Genetic Variability

The presence of differences in the genetic makeup among individuals in a population, which is not explained by blending theory.

Phenotype vs. Genotype

Phenotype refers to the observable traits of an organism, while genotype refers to its underlying genetic makeup.