Sometimes known as acquired characters or Lamarckism, after one of its leading proponents, the French natural philosopher Jean Baptiste de Lamarck (1744-1829), the theory of acquired characteristics is a fallacy that should not be confused with mutation. Acquired characteristics theory maintains that changes that occur in an organism's overall anatomy (as opposed to changes in its DNA) can be passed on to offspring.
Organic compounds made of carbon, hydrogen, oxygen, nitrogen, and (in some cases) sulfur bonded in characteristic formations. Strings of amino acids make up proteins.
A pair of chemicals that form the "rungs" on a DNA molecule, which has the shape of a spiral staircase. A base pair always consists of a type of chemical called a purine on one side and a chemical termed a pyrimidine on the other. This means that DNA base pairs always consist of adenine linked with thymine and guanine with cytosine.
The area of the biological sciences concerned with the chemical substances and processes in organisms.
See somatic cell.
A DNA-containing body, located in the cells of most living things, that holds most of the organism's genes.
An abnormality of structure or function or adisease that is present at birth. Congenital disorders also are called birth defects.
The material inside a cell that is external to the nucleus.
A term for a cell that has the basic number of doubled chromosome cells. In humans, somatic cells, which are diploid cells, have 23 pairs of chromosomes, for a total of 46 chromosomes.
Deoxyribonucleic acid, a molecule in all cells, and many viruses, that contains genetic codes for inheritance.
In genetics, a term for a trait that can manifest in the offspring when inherited from only one parent. Its opposite is recessive.
A protein material that speeds up chemical reactions in the bodies of plants and animals without itself taking part in or being consumed by those reactions.
The application of science to matters of law and legal or police procedure.
A mature male or female germ cell that possesses a haploid set of chromosomes and is prepared to form a new diploid by undergoing fusion with a haploid gamete of the opposite sex.
A unit of information about a particular heritable trait. Usually stored on chromosomes, genes contain specifications for the structure of a particular polypeptide or protein.
The alteration of genetic material by direct intervention in genetic processes.
A sample of a person's DNA that is detailed enough to distinguish it from all other people's DNA.
A process whereby chromosome segments from two parents physically exchange places with each other during the process of meiosis. This is one of the ways that mutation occurs.
The area of biological study concerned with heredity, with hereditary traits passed down from one generation to the next through the genes, and with the variations between organisms that result from heredity.
All of the genetic material in the chromosomes of a particular organism.
One of two basic types of cells in a multicellular organism. In contrast to somatic, or body, cells, germ cells are involved in reproduction.
A mutation that occurs in the germ cells, meaning that the mutation can be passed on to the organism's offspring.
A term for a cell that has half the number of chromosome cells that appear in a diploid, or somatic, cell. In humans, germ cells, which are haploidcells, have 23 unpaired chromosomes, as opposed to the 23 paired chromosomes (46 overall) that appear in a somatic cell.
The transmission of genetic characteristics from ancestor to descendant through the genes.
Capable of being inherited.
The process of cell division that produces haploid genetic material. Compare with mitosis.
A process of cell division that produces diploid cells. Compare with meiosis.
Messenger ribonucleic acid, a molecule of RNA that carries the genetic information for producing proteins.
A chemical or physical factor that increases the rate of mutation.
Alteration in the physical structure of an organism's DNA, resulting in a genetic change that can be inherited.
The process whereby some organisms thrive and others perish, depending on their degree of adaptation to a particular environment.
Acids, including DNA and RNA, that are made up of nucleotide chains.
A compound formed from one of several types of sugar joined with a base of purine or pyrimidine (see base pair ) and a phosphate group. Nucleotides are the basis for nucleic acids.
The control center of a cell, where DNA is stored.
A group of between 10 and 50 amino acids.
Large molecules built from long chains of 50 or more amino acids. Proteins serve the functions of promoting normal growth, repairing damaged tissue, contributing to the body's immune system, and making enzymes.
In genetics, a term for a trait that can manifest in the offspring only if it is inherited from both parents. Its opposite is dominant.
See germ cell.
Ribonucleic acid, a molecule translated from DNA in the cell nucleus that directs protein synthesis in the cytoplasm. See also mRNA.
One of two basic types of cells in a multicellular organism. In contrast to germ cells, somatic cells (also known as body cells ) do not play a part in reproduction; rather, they make up the tissues, organs, and other parts of the organism.
A mutation that occurs in cells other than the reproductive, or sex, cells. These mutations, as contrasted with germinal mutations, cannot be transmitted to the next generation.
To manufacture chemically, as in the body.
A mutation in which chromosomes exchange parts.
A diploid cell formed by the fusion of two gametes.
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