Bio review

Diploid

Cells with two complete sets of chromosomes, one from each parent.

Haploid

Cells with one complete set of chromosomes.

Meiosis

The process of cellular division that produces gametes.

Gametes

Reproductive cells (sperm and eggs) that carry half the genetic information.

Homologous Chromosomes

Chromosomes that have the same genes at the same loci but may have different alleles.

Sister Chromatids

Identical copies of a chromosome that are joined together by a centromere.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Independent Assortment

The random distribution of homologous chromosomes during meiosis.

SRY Gene

A gene on the Y chromosome that is critical for male sex determination.

XY Karyotype

The chromosomal pattern typically associated with male individuals.

XX Karyotype

The chromosomal pattern typically associated with female individuals.

Aneuploidy

An abnormal number of chromosomes in a cell, such as having an extra or missing chromosome.

Sex Chromosomes

Chromosomes that determine the biological sex of an individual (X and Y in humans).

Meiosis I

The first division of meiosis, where homologous chromosomes are separated.

Meiosis II

The second division of meiosis, where sister chromatids are separated.

Zygote

The fertilized egg that results from the union of sperm and egg.

Polygenic Inheritance

A trait that is controlled by multiple genes.

Genetic Variation

Differences in DNA sequences among individuals.

Chromosomal Abnormality

Any change in the normal structure or number of chromosomes.

Fertilization

The union of sperm and egg to form a zygote.

Histone Proteins

Proteins that help package DNA into a compact, organized structure.

Prophase I

The stage of meiosis where crossing over occurs.

Metaphase I

The stage of meiosis where homologous chromosomes line up at the metaphase plate.

Metaphase II

The stage of meiosis where individual chromosomes line up at the metaphase plate.

Alleles

Different forms of a gene found at the same locus on a chromosome.

Locus

The specific location of a gene on a chromosome.

Phenotype

The observable physical or biochemical characteristics of an organism.

Genotype

The genetic constitution of an individual.

Autosome

Any chromosome that is not a sex chromosome.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product.

Dominant Allele

An allele that expresses its trait even when paired with a different allele.

Recessive Allele

An allele that only expresses its trait when paired with another recessive allele.

Bivalent

A pair of homologous chromosomes that are joined together during meiosis.

Centromere

The region of a chromosome where sister chromatids are joined.

Karyotype

A visualization of the chromosome set of a cell, used for diagnosing chromosomal abnormalities.

Sexual differentiation

The process by which individuals develop male or female anatomical and physiological characteristics.

Phenotypic Variation

Variation in physical traits among individuals of a species.

Genetic Drift

Random changes in allele frequencies in a population.

Natural Selection

The process by which individuals better adapted to their environment tend to survive and reproduce.

Mutation

A change in the DNA sequence that can lead to genetic variation.

Mitosis

The process of cell division that results in two identical daughter cells.

Spermatogenesis

The process by which sperm cells are produced in the male.

Oogenesis

The process by which egg cells are produced in the female.

Phenotypic Plasticity

The ability of an organism to change its phenotype in response to environmental factors.

Gene Pool

The total collection of genes and alleles in a population.

Diversity

The variety of different types of life found on earth or in a particular ecosystem.

Evolutionary Advantage

A favorable trait that increases an organism's chances of survival and reproduction.

Outbreeding

The mating of individuals who are not closely related.

Ploidy

The number of sets of chromosomes in a cell.

Genomic Imprinting

A genetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner.

Polyploidy

A condition in which an organism has more than two complete sets of chromosomes.

Environmental Influence

The impact of environmental factors on the expression of genes.

Biological Determinism

The belief that biological factors can determine human behavior and traits.

Somatic Cells

Any cells in the body that are not gametes.

Germ Cells

Reproductive cells that give rise to gametes.

Homozygous

An organism that has two identical alleles for a trait.

Heterozygous

An organism that has two different alleles for a trait.

Telomere

The protective end of a chromosome that prevents degradation.

Antigen

A molecule or molecular structure that is recognized by the immune system.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing proteins based on the information encoded in RNA.

Linked Genes

Genes that are located close to each other on a chromosome and tend to be inherited together.

Chromatin

The complex of DNA and proteins that forms chromosomes.

Gene Therapy

The treatment of disease by altering or supplementing genes.

X-linked Traits

Traits determined by genes located on the X chromosome.

Y-linked Traits

Traits determined by genes located on the Y chromosome.

Somatic Mutations

Mutations that occur in non-germline cells and are not passed to offspring.

Germline Mutations

Mutations that occur in germ cells and can be passed to offspring.

Selective Breeding

The process of breeding plants and animals for specific traits.

Telomerase

An enzyme that adds nucleotides to the ends of chromosomes, maintaining telomere length.

Microevolution

Small-scale changes in allele frequencies within a population over time.

Macroevolution

Large-scale changes that occur over long periods, leading to the emergence of new species.