Allele
one of two or more alternative forms of a gene that arise by mutation
and are found at the same place on a chromosome.
Co-dominance
Alleles that are masked or hidden by dominant
alleles are known as recessive alleles. In some situations, both
alleles are expressed equally. A genetic scenario where neither allele
is dominant or recessive and both get expressed is
known as codominance.
Dominant allele
Dominance in genetics is a relationship between
alleles of one gene, in which the effect on phenotype
of one allelemasks the contribution of a second
allele at the same locus. The first
allele is dominant and the second
allele is recessive.
Gene
(in informal use) a unit of heredity that is transferred from a
parent to offspring and is held to determine some characteristic of
the offspring.
Gene expression
the appearance in a phenotype of a characteristic or effect
attributed to a particular gene.
Genetic engineering
the deliberate modification of the characteristics of an organism by
manipulating its genetic material.
Genetically modified organism
A GMO (genetically modified
organism) is the result of a laboratory process where genes
from the DNA of one species are extracted and artificially forced into
the genes of an unrelated plant or animal. The foreign genes may come
from bacteria, viruses, insects, animals or even humans.
Genotype
the genetic constitution of an individual organism.
Incomplete dominance
Incomplete dominance is a form of intermediate
inheritance in which one allele for a specific trait is not completely
expressed over its paired allele. This results in a third phenotype in
which the expressed physical trait is a combination of the phenotypes
of both alleles.
Multiple alleles
multiple alleles Three or more alternative forms of a
gene (alleles) that can occupy the same locus.
However, only two of the alleles can be present in a
single organism. For example, the ABO system of blood groups is
controlled by threealleles, only two of which are
present in an individual.
Mutation
the changing of the structure of a gene, resulting in a variant form
that may be transmitted to subsequent generations, caused by the
alteration of single base units in DNA, or the deletion, insertion, or
rearrangement of larger sections of genes or chromosomes.
Phenotype
the set of observable characteristics of an individual resulting from
the interaction of its genotype with the environment.
Point mutation
A point mutation, or single base modification, is a
type of mutation that causes a single nucleotide base
substitution, insertion, or deletion of the genetic material, DNA or
RNA. The term frameshift mutationindicates the
addition or deletion of a base pair.
Polygenic trait
Polygenic traits are those traits
that are controlled by more than one gene. Suchtraits
may even be controlled by genes located on entirely different
chromosomes. Human height, eye and hair color are examples of
polygenic traits. Skin color is another
polygenic trait for humans and a variety of other animals.
Protein synthesis
Protein synthesis is the process whereby biological
cells generate new proteins; it is balanced by the loss of cellular
proteins via degradation or export. Translation, the assembly of amino
acids by ribosomes, is an essential part of the biosynthetic pathway,
along with generation of messenger RNA (mRNA), aminoacylation of
transfer RNA (tRNA), co-translational transport, and
post-translational modification. Protein biosynthesis is strictly
regulated at multiple steps.[1] They are principally during
transcription (phenomena of RNA synthesis from DNA template) and
translation (phenomena of amino acid assembly from RNA).
Recessive allele
n an allele that produces its characteristic
phenotype only when its paired allele is identical.
Synonyms: recessive Type of: allele,
allelomorph. (genetics) either of a pair (or series) of alternative
forms of a gene that can occupy the same locus on a particular
chromosome and that control the same character.
Simple dominance
Simple dominance occurs when an inherited trait is
coded for by a single gene and that gene has two versions, or alleles:
the dominant version and the recessive version. The
dominant allele of the gene hides the presence of the
recessive allele.
Sex-linked trait
In humans, red-green colorblindness is a recessive
sex-linked trait. It is found on
the X chromosome, not the Y. Because, males only have one X
chromosome, they have a much greater chance of having red-green
colorblindness. Females would have to be homozygous recessive in order
to have red-green colorblindness.
Transcription
Transcription is the first step of gene expression,
in which a particular segment of DNA is copied into RNA (especially
mRNA) by the enzyme RNA polymerase. Both DNA and RNA are nucleic
acids, which use base pairs of nucleotides as a complementary language.
translation
the process of translating words or text from one language into another.