GENETIC ANALYSIS Flashcards
What is a gene?
a unit of inheritance
What is a genome?
The genetic information of an organism
What is information is contained in the genome?
Contains cellular information that is required for an organism to function
What is the genetic material of a eukaryotic?
DNA in the nucleus, which is organised into chromosomes
What is the structure of eukaryotic genes?
Contains coding sequences and non coding sequences, which are known as exons and introns
What are transposable elements?
Genetic units that have diversity in their structure and transposition membranes
Can transposable elements code for proteins?
Yes, they contain different functional ORFs encoding proteins
What is a locus?
The location of the gene on a region of a chromosome
What are alleles?
Different versions of a gene, e.g. one from mother, one from father
How many alleles are in a diploid organism?
Two - one from each parent
What is a mutant allele?
An allele that differs from the normal alleles found in the wild type
What is a variant allele?
An alteration in the DNA nucleotide sequence
Briefly describe Mendels law of segregation
Each parent passes an allele to their offspring, which results just a diploid organism. The allele containing the dominant trait determines the phenotype
What is genetic recombination?
The exchange of genetic material between chromosomes
What is the importance of recombination?
Evolution, mixing of traits, spreading of traits
Can recombination happen by a single or double strand?
Both
What is incomplete dominance?
Heterozygote produces half the amount of normal protein
What is codominance?
Both alleles are expressed equally and seen in a phenotype
What is a multi allelic trait?
Traits controlled by one gene with two or more alleles
What is pleiotrophy?
An allele that affects more than one trait, affects phenotypes, e.g. sickle cell
What is epistasis?
Traits that affect each other leading to more distinct phenotypes then expected
What is a linkage map?
Arrangement of genes based on inheritance
What is a physical map?
Description of chromosome DNA and distances
What is recombination?
DNA fragments that are exchanged between chromatids
What is recombination important for?
Evolution, mixing traits, spreading traits
What is chiasmata?
Physical link between two chromatids
When does crossing over occur?
Prophase of meiosis I
What does crossing over produce?
New allelic combinations
What is map distance determined by?
The number of crossovers (further apart = higher chance of crossover)
