Topic 1 Single Gene Inheritance Flashcards
What is classical genetics
Inheritance of traits (discovered by Gregor Mendel)
What is molecular genetics
Study of RNA and DNA structure function and molecular control of gene expression
What is meaning of wildtype
The most prevalent phenotype in a population
What is a mutant phenotype
Deviation from Wildtype phenotype as a result of change in allelic dna sequence
What is loss of function
Significant decrease or complete loss of functional gene product
What is gain of function
Gene product acquires new function of expression increased above wildtype activity
Incomplete dominance
Heterozygote display the intermediate phenotype, on all’s is not completely masking the other
Codominance
The Heterozygote expresses both alleles, fighting for expression
What is haplosufficient
To express WT trait you only need one WT allele. The mutation is recessive
What is haploinsufficient
In a Heterozygote, the single WT allele cannot provide enough product for normal function. If you have one mutated allele that allele is shown and is dominant.
Slashes are for _____
Semicolons are for ____
Alleles for genes on homologous chromosome
Alleles for genes on non homologous chromosomes
What is meant by pure breeding
No matter how many times it self crosses the phenotype is always the same
What do gametes contain
Only one allele from each gene pair
What is equal segregation
Half of the gametes carry one member of gene pair half carry the other
What symbols do you use for the dominant trait when writing out genotypes
Uppercase Letter of the recessive or mutant allele ex. Brown is recessive to red
B/B or B/b or b/b
What is the genotype of a tester
Homozygous recessive
What is the P arm of the chromosome
What is the Q arm of the chromosome
The shorter arm
The longer arm
What is telocentric
When there is no p arm, centromere is at the very end of chromosome
What are sister chromatids
Chromosomes from a duplication chromosome that share the exact same genetic info. Not the same as homologous chromosomes
What are homologous chromosomes
2 or more Chromosomes that have the same genes but different alleles. One from mom one from dad. These are not sister chromatids
How do you test for sex linkage?
Carry out a reciprocal cross that swaps the genotypes of the male and female (A/A a/a), if the phenotype ratios are different genes are sex linked
In the f2 both should be present in 3:1 ratio if the genes are inherited autosomal manner
What is heterogametic
Homogametic
No matching pair (XY) male
Matching pair of sex chromosomes (XX) Female
What is a propositus
The first member in family tree that is noticed by a geneticist (usually has disease)
Autosomal recessive pedigree
Disease often shows up from unaffected parents (carriers) both have to be carriers
If both parents have the trait all children will have it
Autosomal dominant pedigree
No skipping of generations (affected individual must have at least one affected parent)
Two affected parents can have unaffected kids but two unaffected parent can’t have affected kids
What are polymorphisms
What are rare diseases
Carriers common
Carriers very uncommon
What do we assume about rates disease when new ppl come into pedigree
The new person is not a carrier for the disease unless proven other wise
X-linked recessive pedigree
More male’s than females affected
If father affected, none of offspring will be affected (assuming the mom isn’t a carrier)
All male offspring from affected female are affected
X-linked dominant rare disease pedigree
All daughters of affected male affected
No sons of affected male affected (unless mother is carrier)
Heterozygous affected female produces affected male and female with equal probability
Djxj
Cjdkje
Cdr
Yyf
