17 - Inherited change Flashcards
Define an allele.
One of a number of alternative forms of a gene.
Define a gene.
A section of DNA on a chromosome coding for one or more polypeptides.
Define a dominant allele.
An allele always expressed in the phenotype of an organism.
Define a recessive allele.
The effect of the allele is apparent in the phenotype of a diploid organism only in the presence of another identical allele.
Define heterozygous.
The condition where the alleles of a particular gene are different.
Define homozygous.
The condition where the alleles of a particular gene are identical.
Define phenotype.
Expression of the genetic constitution and its interaction with the environment.
Define genotype.
The genetic composition of an organism.
Define a chromosome.
A thread-like structure made of protein and DNA by which hereditary information is physically passed from one generation to the next.
Define an autosome.
A chromosome which is not a sex chromosome.
What is a locus? (inheritance)
The position of a gene on a particular DNA molecule.
What is it called when two alleles are expressed in the phenotype?
Codominant
What is the F1 generation?
Name given to the first generation resulting from a homozygous dominant individual being crossed with a homozygous recessive individual.
What sex chromosomes does a male human have?
XY
Is the X or Y chromosome larger?
X
