BI266 Lecture Notes - Lecture 13: Aspirin, Gastrointestinal Disease, Caffeine
Get access
Related Documents
Related Questions
Below you have the sequence of 33 nucleotides(part of a coding region of gene TTr34) from two different species of birds (Species A and Species B). For simplicity, the amino acids encoded by the codons of Species A is also indicated, and â.â indicates the same nucleotide as the one observed in the first sequence.
Pro | Gly | Asn | Thr | His | Glu | Ala | Gln | Lys | Ala | Val | |
Species A | CCT | GGG | AAT | ACT | CAT | GAA | GCA | CAA | AAA | GCC | GTC |
Species B | . . G | . . T | . . C | . . . | . . . | . C . | . . . | . C . | . . T | A . . | . . T |
Use these two sequences to estimate the molecular distances.
a. How many nucleotide changes produce a change in amino acid (nonsynonymous changes)(use the genetic code)?
b. How many nucleotide changes are synonymous (do not cause a change in amino acid)(use the genetic code)?
c. Calculate the molecular distance for synonymous (Ds) and Nonsynonymous (Da) for this gene region without correction. To estimate the total number of synonymous and nonsynonymous sites, assume that 25% of the sites are synonymous and 75% of sites are nonsynonymous.
* Please show all work and explain. *
9.
Snapping shrimp used to be able to swim from the Atlantic Ocean to the Pacific Ocean by traveling between North and South America. However, when the Isthmus of Panama appeared (a land bridge that connects the Americas), the shrimp could no longer travel between the oceans and evolved into different species. This an example of
sympatric speciation | ||||||||||||||||||||||||||||||||||||||
allopatric speciation | ||||||||||||||||||||||||||||||||||||||
punctuated speciation | ||||||||||||||||||||||||||||||||||||||
genetic drift 10. Which of the following refers to a structure that is similar because of descent from a common ancestor (e.g. a human leg and a whale fin)?
|