Chapter 15: the chromosomal basis of inheritance Flashcards
Define the law of separation
The two alleles for each gene will separate
Define the law of independent assortment
alleles of genes on nonhomologous chromosomes assort independently
Describe X inactivation in Female mammals
one of the X chromosomes is inactive so double proteins are not expressed
Each allele is randomly activated during embryonic development
“Mosaic” or two different phenotypes
Linked genes tend to be inherited together because
they are located near each other on the same chromosome
When might Mendel’s law of independent assortment not be true?
chromosomal inheritance, where linked genes can be inherited together because they are near each other on the same chromosome
What are recumbent offspring?
offspring that do not look like the parents
An inversion will
reverse a segment within a chromosome
A translocation will
move a segment from one chromosome to a nonhomologous chromosome
A duplication will
repeat a segment of DNA
Non disjunction is
incorrect distribution of chromosomes across cells
True or false: non disjunction can result in aneuploidy of sex chromosomes
True
note aneuploidy is an incorrect number of sex chromosomes present
TorF: Certain cancers are the result of translocation
true
What is genomic imprinting
the silencing of certain genes depending on which parent passes them on, as two active copies would be detrimental to the offspring
Why do imprinted genes not follow Mendelian pattern of inheritance?
Because imprinting causes offspring to differentiate between maternal and paternal alleles
Imprinting is the result of
methylation