Genes pt.2 Flashcards
What are the steps to transcription?
- RNA polymerase binds to DNA promoter site
- Makes mRNA copy of DNA template
- What is translation?
- Where does it take place?
- RNA directs protein synthesis
- In ribosomes
What are genetic locus?
What are alleles?
Locus= position of gene on chromosome
Allele= different form of gene (1 from father, 1 from mother)
What are polymorphic genes?
Locus that can contain 2 or more alleles in population
What are homozygous loci?
Heterozygous loci?
Homozygous= Locus with identical alleles
heterozygous= Locus that have different alleles/genes
What are the differences in genotype and phenotype?
Genotype= Genetic makeup
Phenotype= physical appearance
What are genetic carriers?
Allele present in genotype, but not phenotype
What are recessive diseases?
What is a common example?
Diseases that require pair of recessive genes to be inherited
Sickle cell anemia
What are pedigrees?
Who does it typically begin with?
Chart that summarizes genetic disorders in family
The first person diagnosed= the proband
What is autosomal dominant inheritance?
What is it most often caused by?
Disease that requires only one affected allele
usually caused by affected heterozygous parent and normal homzygous parent.
Are autosomal dominant diseases common?
What is the recurrent risk with affected parent of offspring?
No, they are rare
50% recurrent risk with
What is autosomal recessive inheritance?
What is an example of disease?
Must have two recessive copies of allele (cc)
cystic fibrosis
If both parents are carriers for a autsomal recessive gene, what is the recurrence risk in children?
25%
What typically causes autosomal recessive diseases?
Consanguinity (mating of relatives)
What does cystic firbosis cause?
Salt imbalances that cause abnormally thick mucus:
Leads to lung disease
