Chap 18 Flashcards
(13 cards)
epigenetics
describes changes in gene expression that are not related to variations of the DNA sequence, yet are transmissible and are reversible
What type of inheritance describes X-chromosome inactivation?
epigenetic
Barr body
A highly condensed X chromosome
In genomic imprinting, the transcription of the imprinted gene is inhibited because
the DNA is methylated
mosaic
female mammals heterozygous for X-linked genes have half their somatic cells expressing each allele
In genomic imprinting, which genes are silenced
Genes inherited from either the mother or the father depending on the gene.
do Barr bodies occur in males and females
yes
In cats, one X allele results in dark fur and another results in orange fur. In an orange fur patch on a calico cat, which X chromosome is inactivated
the X chromosome with the allele for dark fur.
How does X-chromosome inactivation take place
The Xics are counted, allowing the cell to inactivate all but one X chromosome.
which cell provides most of the cytoplasm to the zygote
egg cell
in eukaryotes, where are genes found
nucleus (most of them here), mitochondria, and chloroplasts
The determination of the arrangement of genes in a species’ genome is called
genetic mapping
A linkage group is
a group of genes that usually stay together during meiosis.
