Exam 1 Flashcards
Dominance
Interaction of alleles at a single locus
Epistasis
Interaction between alleles at more than one locus
Chromosome
Discontinuous segment of DNA & proteins
Locus
Specific location on a chromosome
Gene
DNA sequence that encodes for a biological molecule
Allele
Variant in a genome
Sex-linked inheritance
Pattern of inheritance where locus is segregating on sex chromosome
Sex-influenced inheritance
Pattern of inheritance where phenotype is determined by an interaction between genotype & gender
Sex-limited inheritance
Pattern of inheritance where expression of genotype depends on the gender of the individual
Complete dominance
One allele is completely dominant over the other
Partial daominance
One allele is partially dominant of the other
No dominance
Neither allele is displays dominance
Over dominance
The heterozygote is more represented (higher or lower #) than either of the homozygotes
Mendel’s 1st Law
Law of Segregation: At a locus you have a 50% chance of any one allele being transmitted to offspring
Mendel’s 2nd Law
Law of Independent Assortment: The transmission of an allele at a locus does not predict which allele will be transmitted at other loci
What is the exception to Mendel’s 2nd Law?
Linkage
Double recombination
Recombination occurs twice so it appears to be a parental gamete again
Singel-Nucleotide Polymorphism (SNP)
Single base change in DNA
Microsatellite
Variable dinucleotide repeat
Synonymous mutation
Polymorphism that does not change the amino acid sequence
Non-synonymous mutation
Polymorphism that changes amino acid sequence
Missense mutation
Variant that changes amino acid sequence or polymorphism that changes amino acid sequence (non-synonymous mutation)
Nonsense mutation
Variant that produces a stop codon
Point mutation
Single-base pair change or SNP
Frameshift mutation
Small insertion or deletion that changes amino acid sequence
Copy number variant
Large region of the genome that is copied or deleted
Why are linkage and homozygosity mapping often insufficient for identifying a causal variant?
Because the region of the gene is so huge. These methods only get close, but cannot pinpoint.
Causal variant
Variant that causes a phenotypic difference among animals
3 ways to identify causal variants after using linkage or homozygosity mapping
- Look for genes
- Sequence genes
- Take out the gene
Why is GC pairing stronger than AT pairing?
Because GC has 3 H-bonds, while AT has only 2 H-bonds
Purines
Adenine & Guanine
Pyrimidines
Thymine & Cytosine
How many rings do purines have?
2
How many rings do pyrimidines have?
1
What is the function of DNA helicase in replication?
Binds to the DNA near the initiator protein
What are the functions of single-stranded binding proteins?
Bind to single stranded DNA to keep it from reforming
What is the function of DNA polymerase III in replication?
Synthesizes new, complementary strand of DNA
What is the function of RNA primase in replication?
Makes RNA primers
What is the function of DNA polymerase I in replication?
Removes RNA and replaces it with DNA
What is the function of DNA ligase in replication?
Joins DNA strands
Okazaki fragments
Small sections of DNA or lagging strand
What 2 roles are played by RNA polymerase during transcription?
- Unwinds the DNA double helix
- Synthesizes mRNA
3 steps involved in processing RNA
- 5-prime Guanosine cap
- 3-prime Poly-A tail
- Splice out introns
What is the function of splicesome?
Removes introns
