Biology Flashcards: Genetics Terms

Study Notes

Polygenic Inheritance

Involves multiple genes influencing a single trait.
Examples include height and skin color, demonstrating variation in phenotypes.

Allele

Represents a variant form of a gene.
Dominant alleles determine specific characteristics or traits.

Codominance

Occurs when both alleles in a heterozygous genotype are fully and distinctly expressed.
An example of codominance can be seen in certain blood types where both alleles contribute to the phenotype.

Autosomes

Comprise chromosomes 1-44 in humans.
Non-sex chromosomes, consisting of 22 pairs, with one pair being sex chromosomes.

Recessive

An allele that is only expressed in a homozygous state, meaning both copies must be the recessive form.
Example: The long-hair gene in animals is a recessive trait.

Sex Linked

Genes that are located on sex chromosomes, primarily the X chromosome.
Traits linked to genes on the X or Y chromosome are referred to as sex-linked traits.

Law of Independent Assortment

States that genes separate independently during meiosis due to the random alignment of chromosomes during metaphase.
Important principle in Mendelian genetics regarding inheritance patterns.

Karyotype

A visual representation of a complete set of chromosomes, arranged in homologous pairs.
Useful in genetic analysis and can be obtained via techniques like amniocentesis.

Protein

Essential macromolecules that perform various functions in the body and express traits.
Composed of chains of amino acids, highlighting the role of proteins in biological processes.

Heterozygous

A genotype characterized by the presence of two different alleles inherited from each parent.
Example: An organism that is heterozygous for eye color has different alleles for that trait.

Gene

A specific segment of DNA on a chromosome that encodes for a single protein.
Key in determining various traits and traits expression.

Linked Genes

Genes located close together on the same chromosome, increasing the likelihood of being inherited together.
These genes can influence similar phenotypic traits due to their proximity on the chromosome.

Dominant

An allele that overshadows the effect of another allele in a heterozygous organism.
Dominance reflects the strength of influence a particular allele has on trait expression.

Phenotype

Refers to the observable physical characteristics of an organism resulting from the genotype.
Phenotypic expression reflects both genetic and environmental influences on an organism.

Description

Test your knowledge of key genetics terms with these flashcards. Learn about polygenic inheritance, alleles, and other essential concepts that shape our understanding of heredity. Perfect for anyone looking to brush up on their biology vocabulary.