Homology

Question 1

define homology

Answer 1

Features of organisms that are evolutionarily related

1. can be organs/nucleotide sequences
2. either homologous/ not homologous

Question 2

what are homologous chromosomes please give an example

Answer 2

Homologous chromosomes are duplicate chromosomes
Typically a chromosome from mother and a chromosome from father
i.e eyecolor

Question 3

What are homologous genes?(please provide examples)

Answer 3

2+ genes that are derived from the same ancestral gene

i. e- PAX6 in humans for eye development many animals have it = parsimonious explanation= homologous
- uses multiple sequence alignment comparison

Question 4

what is multiple sequence alignment and how is it used?

Answer 4

3+ DNA, RNA, or protien sequences aligned to indicate evolutionary relationships
*character matrix of sequence done in cladistics lab

Question 5

Using computational phylogenetics

Answer 5

1. Uses homologous genes and aligns them
2. uses this alignment to build a tree

method used= maximum parsimony
maximum parsimony chooses the tree with least amount of changes