chapter 4 Flashcards
what are structural genes
Genes that contain the informa tion to make a protein.
what are regulatory genes?
Genes that guide the expression of structural genes, without coding for a protein themselves.
what is the genotype?
The genetic makeup of an individ ual. Genotype can refer to the entire genetic complement or more narrowly to the alleles present at a specific locus on two homologous chromosomes.
what is a phenotype?
An observable or measurable feature of an organism. Phenotypes can be anatomical, biochemical, or behavioral.
what is the ABO blood type system?
Refers to the genetic system for one of the proteins found on the surface of red blood cells. Consists of one gene with three alleles:
A, B, and O.
recessive defintion:
In a diploid organism, refers to an allele that must be present in two copies (homozygous) in order to be expressed.
what is particulate inheritance?
The concept of heredity based on the transmission of genes (alleles) according to Mendelian principles.
what is Mendel’s law of segregation?
The two alleles of a gene found on each of a pair of chromosomes segregate independently of one another into sex cells.
what is Mendel’s law of independent assortment?
Genes found on different chro mosomes are sorted into sex cells independently of one another.
what is autosomal recessive disease?
A disease caused by a recessive allele; one copy of the allele must be inherited from each parent for the disease to develop.
what is insertion mutation?
A change in the base sequence of a gene that results from the addition of one or more base pairs in the DNA.
what is a deletion mutation?
A change in the base sequence of a gene that results from the loss of one or more base pairs in the DNA.
what is autosomal dominant disease?
A disease that is caused by a domi nant allele: Only one copy needs to be inherited from either parent for the disease to develop.
what are trinucleotide repeat diseases?
A family of autosomal dominant diseases that is caused by the insertion of multiple copies of a threebasepair sequence (CAG) that codes for the amino acid glu tamine. Typically, the more copies inserted into the gene, the more serious the disease.
what are X-linked disorders?
Genetic conditions that result from mutations to genes on the
X chromosome. They are almost always expressed in males, who have only one copy of the X chro mosome; in females, the second X chromosome containing the nor mally functioning allele protects them from developing Xlinked disorders.
