Flashcards in Chapter 14/15 Deck (30):
Law of segregation
Two alleles for a gene segregate during meiosis into separate gametes
Law of independent assortment
One pair of homologous chromosomes moving to opposite poles does not affect the movement of other homologs
What gene on the Y chromosome codes for development of testes?
What are genes on the sex-linked chromosomes called?
1 gene alters phenotypic expression of gene at another locus
Genes that vary along a continuum
Many genes affect one phenotype
1 gene gives multiple phenotypic effects
Norm of reaction
Phenotypic possibilities for a certain genotype
Genetic and environmental factors influence phenotype
What are the 2 fetal testing techniques?
-Chorionic villus sampling (CVS)
Because there are 2 X chromosomes in a sex-linked homolog, one X chromosome condenses into a Barr body
Do Barr bodies inactivate independently?
(Either maternal/paternal can condense. Embryo ends up having 1/2 maternal inactivated and 1/2 paternal inactivated)
Two or more genes on the same chromosome that are physically connected and sort dependently
How do nonparental phenotypes occur from linked genes?
Crossing over of homologous pairs during meiosis
Ordered list of genetic loci along a chromosome
Genetic map based upon recombination frequencies
Gene positions indicated with respect to chromosomal features
What are the three types of chromosomal alterations (2 are abnormal chromosome number)
-Breakage of chromosome
When homologous pairs do not separate normally during meiosis
Fertilization of gametes in which nondisjunction of a homolog has occured in a gamete
When an organism has more than 2 complete sets of chromosomes
Types of aneuploidy?
Types of Polyploidy?
Types of breakages of chromosome
Klinefelter syndrome (XXY) and Turner Syndrome (XO) are the result of what?
Aneuploidic sex chromosomes. In Klinefelter, sex chromosome is trisomic, and in turner syndrome, sex chromosome is monosomic
What are the 2 exceptions to normal mendelian genetics?
1. Genomic imprinting intranucleus
2. Defective extranuclear genes
When the phenotype passed down depends on which parent passed down the allele, what is happening?
Genomic imprinting silences the maternal/paternal allele