Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology II > Phylogenies & the History of Life > Flashcards

Phylogenies & the History of Life Flashcards

Chapter 20 of the book

1
Q

What is Phylogeny?

A

The evolutionary history & relationship of an organism or group of organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does a phylogeny describe?

A

The organism’s relationship, such as from which organisms it may have evolved, or to which species it is more closely related.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do phylogenetic relationships provide information on?

A

Shared ancestry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Phylogenetic Tree?

A

A diagram used to reflect evolutionary relationships among organisms or groups of organisms. Shows the evolutionary pathways & connections among organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Many phylogenetic trees have a single lineage at the base that represents what?

A

A common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Rooted?

A

Single ancestral lineage (typically drawn from the bottom or left) on a phylogenetic tree to which all organisms represented in the diagram relate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do unrooted trees not show?

A

A common ancestor but they do show relationships among species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do the branches in a rooted tree (typical Phylogenetic tree) indicate?

A

Evolutionary relationships

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a Branch Point?

A

Node on a phylogenetic tree where a single lineage splits into distinct new ones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a Basol Taxon?

A

Branch on a phylogenetic tree that has not diverged significantly from the root ancestor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a Sister Taxa?

A

Two lineages that diverged from the same branch point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a Polytomy?

A

Branch on a phylogenetic tree with more than two groups or taxa (lineage). Serves to illustrate where scientists have not definitively determined all of the relationships.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Do groups of organisms that have a common ancestor evolve from one another?

A

No, neither give rise to the other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Does the rotation at branch points on a phylogenetic tree change information?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Systematics?

A

Field of organizing & classifying organisms based on evolutionary relationships.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Are phylogenetic trees hypotheses?

A

Yes & they continue to change as researchers discover new types of life & learn new information.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Is it ALWAYS true that the more closer organisms look alike, the more they are closely related?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Do the branches on a phylogenetic tree account for length of time?

A

No, instead they show the order in which things took place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a Taxonomy?

A

Science of classifying organisms to construct internationally shared classification systems with each organism placed into increasingly more inclusive groupings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the organization from larger to smaller, more specific categories called?

A

Hierarchical system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What model does the taxonomic classsification system use?

A

Hierarchical Model.
Moving from the point of origin, the groups become more specific, until one branch ends as a single species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 3 large categories (domains)?

A
  1. Bacteria
  2. Archaea
  3. Eukarya
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the classification levels? (The first being the broadest & the last being the most specific)

A
  1. Domain
  2. Kingdom
  3. Phylum
  4. Class
  5. Order
  6. Family
  7. Genus
  8. Species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a Binomial Nomenclature?

A

System of two-part scientific names for an organism, which includes genus & species names.

25
What is a taxon?
(plural: Taxa) Single level in the taxonomic classification system.
26
What is a subspecies?
Are members of the same species that are capable of mating & reproducing viable offspring, but they are separate subspecies due to geographic or behavioral isolation or other factors.
27
What 2 types of evidence do evolutionary investigations focus on?
1. Morphologic (Form & Function) 2. Genetic
28
Is true that organisms that share similar physical features & genomes are more closely related than those that do not?
Yes.
29
What are homologous structures?
Features that overlap morphologically (in form) & genetically.
30
Are the same relationships b/w complexity & shared evolutionary history true for homologous structure in organisms true?
Yes
31
What is a Analogy?
A.K.A. homoplasy, characteristics that is similar b/w organisms by convergent evolution, NOT due to the same evolutionary path.
32
When do analogous structures occur?
Due to environmental constraints, NOT due to evolutionary relationships
33
What is the difference b/w homologous structures & analogous structures?
Homologous structures share a similar embryonic structure. Analogous structures have similar functions.
34
What are Molecular Systematics?
Techniques using molecular evidence/data in taxonomy & biological geography to identify phylogenetic relationships.
35
How do scientists construct phylogenetic trees?
After they sort the homologous & analogous traits, scientists often organize the homologous using cladistics.
36
What are Cladistics?
a system to organize homologous traits to describe phylogenies
37
What are Clades?
Groups of organisms that descended from a single ancestor. They can vary in size depending on which branch point one references.
38
What is a Monophyletc group?
A single clade (organisms that share a single ancestor).
39
What must Clades include?
All descendants from a branch point.
40
What is the important factor for all organisms in the clade or monophyletic group?
They stem from a single point on the tree
41
What pattern repeats as one goes through the phylogenetic tree of life?
1. A change in an organism's genetic makeup leads to a new trait which becomes prevalent in the group. 2. Many organisms descend from this point & have this trait 3. new variations continue to arise: some are adaptive & persist, leading to new traits 4. With new traits, a new branch point is determined
42
What is a Shared Ancestral Character?
Describes a characteristic/trait on a phylogenetic tree that all organisms on the tree share.
43
What is a Shared Derived Character?
Describes a characteristic/trait on a phylogenetic tree that only a certain clade of organisms share.
44
What does it mean that a taxonomy is subjective discipline?
Many organisms have more than one connection to each other, so each taxonomist will decide the order of connections.
45
What is Maximum Parsimony?
Applying the simplest, most obvious way with the least number of steps. Scientists use this to aid in the tremendous task of describing phylogenies accurately.
46
What is the Horizontal Gene Transfer (HGT)?
A.K.A. the Lateral gene transfer, transfer of genes b/w unrelated species
47
Where are HGT mechanisms most commonly found?
Bacteria & Archaea Domains
48
What does the Endosymbiont Theory purport?
That the eukaryotes' mitochondria & the green plants' chloroplasts & flagellates originated as free-living prokaryotes that invaded primitive eukaryotic cells & become established as permanent symbionts in the cytoplasm.
49
What are the 3 gene transfers that bacteria uses?
1. Transformation: bacteria takes up naked DNA 2. Transduction: a virus transfers the genes 3. Conjugation: a hollow tube, or pilus transfers genes b/w organisms.
50
What are Gene Transfer Agents (GTAs)?
Bacteriophage-like particle that transfers random genomic segments from one species of prokaryote to another.
51
What is Genome Fusion?
Fusion of two prokaryotic genomes, presumably by endosymbiosis. Occurs when one species is taken inside another species' cytoplasm, which results in a genome consisting of genes from both the Endosymbiont & the host.
52
What is Genome Fusion an aspect of?
The Endosymbiont Theory
53
How are gram-negative bacteria unique within their domain?
They contain 2 lipid bilayer membranes that resulted from an endosymbiotic fusion of archaea & bacterial species.
54
What is the Nucleus-first hypothesis?
Proposal that prokaryotes acquired a nucleus first, & then the mitochondrion.
55
What is the Mitochondria-first hypothesis?
Proposal that prokaryotes acquired a mitochondrion first, followed by nuclear development.
56
What is the Eukaryote-first hypothesis?
Proposal that prokaryotes evolved from eukaryotes'.
57
What is the "Web of life" Model?
Phylogenetic model that attempts to incorporate the effects of horizontal gene transfer on evolution. Resembles a web or network more than a tree. Hypothesizes that eukaryotes evolved from a pool of many species that were sharing genes by HGT mechanisms.
58
What is the "Ring of life" Model?
Phylogenetic model where all 3 domains of life evolved from a pool of primitive prokaryotes. A ring-like model.

Biology II (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions