Epigenetics and Linkage Flashcards
Define epigenetics and give 3 examples of it.
Types of changes in gene expression that are at a level that goes beyond changes in DNA sequences. An epigenetic effect begins with an initial event that causes a change in gene expression. 3 examples are DNA methylation, Histone modification, and RNA-mediated events.
What is a model organism?
non-human species that are used in the laboratory to help scientists understand biological processes.
Define chromosome mapping.
Genetic mapping shows linear arrangement of genes, it allows us to estimate the relative distances between linked genes based on the frequency of cross over.
Describe the process that determines maleness (in humans).
the sex chromosome that a male sperm carries determines whether the offspring will develop into a male or a female.
Describe X inactivation and how it works in calico cats.
The patchy pattern is due to permanent inactivation of one X chromosome in each skin cell. One of the two X chromosomes is randomly inactivated in each somatic cell. One or the other X is inactivated in different groups of cells, resulting in patches of black and orange fur.
Describe Barr bodies.
Cells of humans and other mammals that have the ability to count X chromosomes and allow only one to be active.
Describe 2 types of Extranuclear Inheritance and give examples of each.
Paternal Inheritance: only the pollen contributes these organelles, (most types of pine trees).
Maternal Inheritance: In most plants, the egg cell provides most of the zygotes ctycoplasm, chloroplasts are most often inherited via the egg, (most common pattern in seed-bearing plants).
