- the entire complement of genetic material in a chromosome set.
- an organism’s unique and complete set of genetic
- information (DNA)
a linear end-to -end arrangement of genes and other DNA, sometimes with associated protein and RNA
the fundamental physical and functional unit of heredity, which carries information from one generation to the next; a segment of DNA composed of a transcribed region and a regulatory sequence that makes transcription possible
- deoxyribonucleic acid
- a chain of linked nucleotides (having deoxyribose as their sugars). Two such chains in double helical form are the fundamental substance of which genes are composed.
a cell having one chromosome set or an organism composed of such cells
a cell having two chromosome sets or an individual organism having two chromosome sets in each of its cells
the basic unit of eukaryotic chromosome structure; a ball of eight histone molecules that is wrapped by two coils of DNA
- the substance of chromosomes; now known to include DNA and chromosomal proteins.
- condense chromatin = chromosome
- densely staining condensed chromosomal regions, believed to be for the most part genetically inert.
- dense packing, dark staining, generally inactive
- a less-condensed chromosomal region, thought to contain most of the normally functioning genes.
- looser packing, lighter staining, more active (transcriptionally)
- a specialized region of DNA on each eukaryotic chromosome that acts as a site for the binding of kinetochore proteins.
- dense chromatin near “center” ofchromosome
- the tip, or end, of a chromosome.
- the “tips” of a chromosome, also somewhat dense – think of it as the knots that keep a chromosome from unraveling
- any chromosome that is not a sex chromosome.
- autosomal chromosome --> 22 pairs --> does not differ male to female
- a chromosome whose presence or absence is correlated with the sex of the bearer; a chromosome that plays a role in sex determination.
- sex linked --> the XX or XY pair
- aka intervening sequence
- a segment of largely unknown function within a gene. This segment is initially transcribed, but the transcript not found in the functional mRNA.
- The non-expressed (transcribed but not translated) portion of the coding sequence of a gene.
- any nonintron section of the coding sequence of a gene; together, the exons correspond to the mRNA that is translated into protein.
- the expressed (transcribed and translated) portion of the coding sequence
The space between genes. Not transcribed or translated but may serve a regulatory function.
- one of the different forms of a gene that can exist at a single locus.
- a form or variant of a gene. Usually comes in “wild type” and “mutant(s)”. Wild type is usually defined as the most common form (and is often dominant to any variants/mutants). In a population there can be multiple alleles.
refers to the state of carrying a pair of identical alleles at one locus
refers to the state of carrying a pair of different alleles at one locus
- (1) the form taken by some character (or group of characters) in a specific individual. (2) the detectable outward manifestations of a specific genotype.
- Observable expression of genotype. Morphological, biochemical, physiological or behavioral trait. Changes throughout life; influenced by environment & development.
- Phenotype = genotype x environment x development
- the specific allelic composition of a cell - either of the entire cell or, more commonly, of a certain gene or a set of genes.
- Gene(s) associated with a given trait. Essentially a fixed character of an organism (except for rare mutations).
- a type of nuclear division (occurring at cell division) that produces two daughter nuclei identical with the parent nucleus.
- “conservative” division mother and daughter cells identical
- two successive nuclear divisions (with corresponding cell divisions) that produce gametes (in animals) or sexual spores (in plants and fungi) that have one-half of the genetic material of the original cell.
- “reductive” division mother and daughter cells different
- (1) four homologous chromatids in a bundle in the first meiotic prophase and metaphase. (2) the four haploid product cells from a single meiosis.
- Four homologous chromatids in a bundle in the first meiotic prophase and metaphase
a pair of sister chromatids joined at the centromere, as in the first division of meiosis.
- one of the two side-by-side replicas produced by chromosome division.
- together in the "x" formation
- a member of a pair of homologous chromosome.
- The two members of a chromosome pair in a cell
a gene present in only one copy in a diploid organism - for example, an X-linked gene in a male mammal.
- equal numbers of progeny genotypes attributable to the separation of two alleles of one gene at meiosis.
- Mendel's first law:
- the two members of a gene pair segregate from each other in meiosis; each gamete has an equal probability of obtaining either member of the gene pair
- Mendel's second law:
- unlinked or distantly linked segregating gene paris assort independently at meiosis.
- gene pairs on different chromosome pairs assort independently at meiosis
- (1) in general, any process in a diploid or partly diploid cell that generates new gene or chromosomal combinations not previously found in that cell or in its progenitors. (2) at meiosis, the process that generates a haploid product of meiosis whose genotype is different from either of the two haploid genotypes that constituted the meiotic diploid.
- Meiosis generates recombinants, which are haploid meiotic products with new combinations of the alleles/chromosomes than carried by the haploid genotypes that united to form the meiocyte.
polygenes/quantitative trait loci (QTL)
- aka multiple factor hypothesis
- a hypothesis that explains quantitative variation by assuming the interaction of a large number of genes (polygenes), each with a small additive effect on the character.
- QTL: a gene affecting the phenotypic variation in continuous varying traits such as heigh and weight, among others