Sex Determination and Patterns of Genetic Transmission

Vocabulary flashcards covering sex determination mechanisms and principles of genetic transmission based on the lecture material.

Sex Chromosomes

The 23rd pair of chromosomes that determines a baby's sex; females have two X chromosomes (XX) and males have one X and one Y chromosome (XY).

Sperm's Role (Sex Determination)

The factor determining a child's sex, as the father's sperm carries either an X chromosome (resulting in female XX) or a Y chromosome (resulting in male XY).

Sexual Differentiation

A complex process involving the SRY gene on the Y chromosome, which triggers the development of testes and testosterone production in genetically male embryos.

SRY Gene

A gene located on the Y chromosome that triggers the development of testes during sexual differentiation.

Gregor Mendel

The individual who laid the foundation for modern genetics through studies of pea plants, identifying dominant and recessive traits.

Alleles

Alternative forms of a gene that occupy the same position on paired chromosomes and affect the same trait.

Homozygous

Possessing two identical alleles for a trait (e.g., RR or rr).

Heterozygous

Possessing differing alleles for a trait (e.g., Rr).

Dominant Inheritance

A pattern of inheritance where the dominant allele is always expressed, even if the other allele is recessive.

Recessive Inheritance

A pattern of inheritance where the trait is expressed only if the individual has two recessive alleles (homozygous recessive).

Polygenic Inheritance

An inheritance pattern in which many genes work together to influence a complex trait (e.g., intelligence, height, skin color).

Multifactorial Transmission

The combination of genetic and environmental factors to produce complex traits.

Genotype

The underlying genetic makeup of a person.

Phenotype

The observable characteristics of a person, which are the product of genotype and environmental influences.

Epigenesis (Epigenetics)

A mechanism that turns genes on or off without altering the DNA sequence, which can be caused by environmental factors and potentially inherited.

Epigenetic Drift

Accumulated epigenetic differences between identical twins over time due to differing experiences.

Genome Imprinting

Differential expression of certain genes depending on whether they are inherited from the mother or the father.