Creating Phylogenetic Trees from DNA Sequences (from website)

Question 1

the more features that are shared, the more likely the species are to be __ __ in evolution

Answer 1

closely related

Question 2

Anatomy allows __ __ comparisons but does not allow __ comparisons

Answer 2

• physical trait
• genetic

Question 3

can also be compared to study relationships

Answer 3

molecular sequences (DNA, RNA, protein)

Question 4

When done properly, __ comparison can be more objective and less ambiguous than __ comparison

Answer 4

• sequence
• anatomical

Question 5

technology that have made many DNA sequences from many different organisms available

Answer 5

Rapid DNA sequencing technology

Question 6

Evolutionary related organisms share a __ __ with an __ __ __

Answer 6

• common ancestor
• ancestral DNA sequence

Question 7

as organisms evolve and diverge, their DNA sequences accumulate differences, also known as __

Answer 7

mutations

Question 8

Two common types of mutations

Answer 8

1. SNPs
2. Indels

Question 9

change of one DNA base pair into another

Answer 9

Single nucleotide polymorphism (SNP)

Question 10

mutation in which one or more nucleotide pairs in a DNA strand is lost or gained

Answer 10

Indels

Question 11

before comparing sequences, stretches of DNA must be __ __

Answer 11

evolutionary related

Question 12

an __ indicates that all the letters in that column match

Answer 12

asterisk

Question 13

an indel in an alignment will be represented by a __ (sometimes a __) in the alignment

Answer 13

• gap
• dash

Question 14

One method to create a phylogenetic tree

Answer 14

1. find two most similar sequences
2. work backwards to find less closely related

Question 15

within a tree, the end of each branch represents a __ or __, or a group of related ____

Answer 15

• species
• sequence
• species/sequence

Question 16

place where two branches split apart

Answer 16

branch point

Question 17

branch points represent the most __ __ __ of all the species on those branches

Answer 17

recent common ancestor

Question 18

single branch point from which all branches originate

Answer 18

root

Question 19

Phylogenetic trees can also be __

Answer 19

unrooted

Question 20

Unrooted trees only show you __ __ among compared organisms and do not tell where the __ __ is among a group of species

Answer 20

• relative relationships
• common ancestor

Question 21

Phylogenetic trees made using DNA sequences are usually very similar to trees made using other evidence, such as __ __

Answer 21

comparative anatomy

Question 22

Trees can also help clear up __ or __ generated by other methods, such as comparative anatomy

Answer 22

• ambiguities
• uncertainties