Terms Used in Modern Genetics (10.1) Flashcards
Define Genes
Heritable units of information about traits.
What is the locus?
The specific location where a gene occurs on a specific chromosome.
What do cells with a diploid chromosome number (2n) have?
They have a pair of genes, on pairs of homologous chromosomes.
What is a mutation?
A permanent change in a gene and in the information it carries. It may cause a trait to change, such as changing the colour of a flower.
What are all molecular forms of the same gene known as?
Alleles.
What is true-breeding lineage?
When an offspring inherits a pair of identical alleles for a trait generation after generation.
What is a hybrid?
The offspring of a cross between two true-breed individuals. A hybrid inherited two nonidentical alleles for the traits.
When does a heterozygous condition occur?
When there are two different alleles at the same gene locus on homologous chromosomes.
When does a homozygous condition occur?
When the homologous chromosomes carry the same allele.
When is an allele dominant?
When its effect on a trait masks the effect of any recessive allele paired with it.
What is a homozygous dominant individual?
A homozygous dominant individual has a pair of dominant alleles.
What is a heterozygous individual?
A heterozygous individual has a pair of nonidentical alleles.
What is a heterozygous recessive individual?
A homozygous recessive individual has a pair of recessive alleles.
What is gene expression?
Gene expression is the process by which a gene’s information is converted to a structural or functional part of a cell. Expressed genes determine traits.
Define Genotype
Genotype refers to the particular alleles that an individual carries.
Define Phenotype
Phenotype refers to an individual’s traits.
What does F1 and F2 stand for?
F1 is the first-generation offspring, F2 is the second-generation offspring of self-fetilized or intercrossed F1 individuals.
