ib bio hl genetics

Genome

All genetic information in an organism, present in every cell.

Diploid

Cells containing two sets of homologous chromosomes.

Homologous Chromosomes

Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Locus

The specific physical location of a gene on a chromosome.

Gene

A segment of DNA that determines a specific trait.

Allele

A variant form of a gene that can cause different traits to be expressed.

Prokaryotic Chromosomes

Single circular chromosome 'naked' DNA, plus plasmids, found in prokaryotes.

Eukaryotic Chromosomes

Multiple linear chromosomes associated with histones, enclosed in a nucleus, found in eukaryotes.

Karyotype

A display of the complete set of chromosomes in a cell, used to diagnose genetic disorders.

Karyogram

A visual representation of an organism's chromosomes used to reveal abnormalities.

Dominant Allele

An allele that masks the effect of a recessive allele in a heterozygous genotype.

Recessive Allele

An allele that is masked by a dominant allele in a heterozygous genotype.

Codominance

A genetic scenario where both alleles are fully expressed in the phenotype (e.g., blood groups IA and IB).

Incomplete Dominance

A genetic situation where the heterozygous phenotype is intermediate between the two homozygous phenotypes.

Sex-linked Trait

A trait associated with a gene located on a sex chromosome, often showing unique inheritance patterns.

Pedigree Chart

A diagram that tracks the inheritance of traits over generations in a family.

Genetic Disease

A disorder that is caused by abnormalities in genes or chromosomes, which can be dominant or recessive.

Polygenic Inheritance

A type of inheritance where multiple genes impact a trait, leading to continuous variation.

Chi-squared Test

A statistical method to determine if there is a significant difference between observed and expected frequencies.

Crossing Over

The process during meiosis where homologous chromosomes exchange segments, generating genetic diversity.