Advertisement Upgrade to remove ads


the biological process whereby genetic factors are transmitted from one generation to the next.


a distinguishing feature of your personal nature.


the branch of biology that studies heredity and variation in organisms.


a mature sexual reproductive cell having a single set of unpaired chromosomes.


process in sexual reproduction in which male and female reproductive cells join to form a new cell.


the cell resulting from the union of an ovum and a spermatozoon (including the organism that develops from that cell).


transfer of pollen from the anther to the stigma of a plant.


an organism that is the offspring of genetically dissimilar parents or stock.


one of two alternate forms of a gene that can have the same locus on homologous chromosomes and are responsible for alternative traits.


trait that will show up in an organism's phenotype if gene is present.


The inherited characteristic often masked by the dominant characteristic and not seen in an organism.

Law of Segregation

members of a pair of homologous chromosomes separate during the formation of gametes and are distributed to different gametes so that every gamete receives only one member of the pair.


what an organism looks like as a consequence of its genotype.


the particular alleles at specified loci present in an organism.


having identical alleles at corresponding chromosomal loci.


having dissimilar alleles at corresponding chromosomal loci.

Law of Independent Assortment

each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random.


an organism or cell having two sets of chromosomes or twice the haploid number.


an organism or cell having only one complete set of chromosomes.

Homologous Chromosome

one of a matching pair of chromosomes, one inherited from each parent.


cell division that produces reproductive cells in sexually reproducing organisms.


the male reproductive cell.


Female sex cell.

Sexual Reproduction

process by which cells from two different parents unite to produce the first cell of a new organism.

Crossing Over

the interchange of sections between pairing homologous chromosomes during the prophase of meiosis.

Genetic Recombination

the regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents.


meiosis in which there is a failure of paired homologous chromosomes to separate.

Nitrogenous Base

an organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA.

Double Helix

a pair of parallel helixes intertwined about a common axis.

DNA Replication

the process of making a copy of DNA.

Messenger RNA

the template for protein synthesis.

Ribosomal RNA

type of RNA that makes up the major part of ribosomes.

Transfer RNA

type of RNA molecule that transfers amino acids to ribosomes during protein synthesis.


the organic process whereby the DNA sequence in a gene is copied into the RNA.


a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid.


the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm.


any event that changes genetic structure.

Point Mutation

a mutation due to an intramolecular reorganization of a gene.

Frameshift Mutation

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide.

Chromosomal Mutation

any event that changes genetic structure.


any agent (physical or environmental) that can induce a genetic mutation or can increase the rate of mutation.


the descendants of one individual.


a person who has some pathogen to which he is immune but who can pass it on to others.


the developing human organism from 9 weeks after conception to birth.

Incomplete Dominance

one allele is not completely dominant over the other allele.

Codominant Allele

both alleles are equally expressed.

Multiple Allele

presence of more than two alleles for a genetic trait.


any chromosome that is not a sex chromosome.

Sex Chromosome

a chromosome that determines the sex of an individual.

Sex-linked Trait

a trait that is determined by a gene found on one of the sex chromosomes, such as the X chromosome or the Y chromosome in humans.

Polygenic Inheritance

combined effect of two or more genes on a single character.


the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number and arrangement and size and structure of the chromosomes).


the act of mating closely related individuals.

Test Cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype.

Genetic Engineering

the technology of preparing recombinant DNA in vitro by cutting up DNA molecules and splicing together fragments from more than one organism.

Recombinant DNA

genetically engineered DNA made by recombining fragments of DNA from different organisms.

Transgenic Organism

organisms that contain functional recombinant DNA from a different organism.

Restriction Enzyme

any of the enzymes that cut nucleic acid at specific restriction sites and produce restriction fragments.


a variable quantity that can be resolved into components., any agent (person or animal or microorganism) that carries and transmits a disease.


a small cellular inclusion consisting of a ring of DNA that is not in a chromosome but is capable of autonomous replication.


a group of genetically identical cells or organisms derived from a single cell or individual by some kind of asexual reproduction.

Human Genome

the approximately 35,000-40,000 genes on the 46 human chromosomes.

Linkage Map

A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.

Gene Therapy

The insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording