Animal Phylogeny

Question 0

What organism do we believe that animals originate from?

Answer 0

Choanoflagellates

Question 1

What makes an Animal? 7 key traits

Answer 1

Multicellular eukaryotes
Heterotroph
Most have tissues
Locomotion at some point in life
React to stimuli
Capable if sexual reproduction
Have a blastula at some point during life cycle

Question 2

What types of symmetry are organisms classified by?

Answer 2

Asymmetrical
Radial
Bilateral

Question 3

What are the three types of Bilateral Symmetry?

Answer 3

Fluctuating asymmetry
Directional asymmetry
Antisymmetry

Question 4

What is meant by fluctuating asymmetry?

Answer 4

When they are not entirely symmetrical across their sagittal section, this is us.

Question 5

What us meant by directional asymmetry?

Answer 5

Weighted to one side

Question 6

What are the advantages of cephalization?

Answer 6

Increases effectiveness of a bilateral animal to find food and detect enemies

Question 7

What are the key characteristics of protostomes?

Answer 7

Spiral cleavage
Blastopore becomes mouth
Schizocoelous

Question 8

What are the characteristics of deuterostomes?

Answer 8

Radial cleavage
Blastopore to anus
Enterocoelous

Question 9

What is an acoelomate?

Answer 9

No coelom

Question 10

What is a pseudocoelomate?

Answer 10

Have a fake coelom, not completely surrounded by mesoderm

Question 11

What are coelomates?

Answer 11

Animals with a body cavity surrounded by mesoderm

Question 12

What does the ectoderm become?

Answer 12

Body covering and the nervous system

Question 13

What does the endoderm become?

Answer 13

Gut lining and digestive organs

Question 14

What does the mesoderm become?

Answer 14

The muscle

Question 15

What are the categories in animal phylogeny, in descending order?

Answer 15

Domains
Kingdoms
Phyla
Class
Order
Family
Genus
Species

Question 16

What are the 6 kingdoms?

Answer 16

Archaebacteria
Eubacteria
Protista
Plantae
Fungi
Animalia

Question 17

What are the 3 domains?

Answer 17

Archae
Eubacteria
Eukarya

Question 18

What is a monophyletic taxon?

Answer 18

All the descendants of the most common ancestor are included

Question 19

What is a paraphyletic taxon?

Answer 19

A group with a common ancestor however not all common ancestors are included

Question 20

What is a polyphyletic taxon?

Answer 20

These do not share a common ancestor, but share homoplastic features

Question 21

What is a molecular clock?

Answer 21

A method of measuring the time since the divergence from a common ancestor by the number of differences in nucleotides or protein sequences.

Question 22

What is the main problem with the molecular clock?

Answer 22

It relies upon the rate of change being constant

Question 23

What is a phyla?

Answer 23

A phyla is a largest generally accepted group of animals which share fundamental aspects of their Biology

Question 24

What is outgroup analysis?

Answer 24

Seperate ancestral and derived characeristics

Question 25

What does cladistics do?

Answer 25

Emphasises common ancestry over phenotypic similarity

Question 26

What is the cambrian explosion?

Answer 26

A time period over 500 mya when all the major phyla orginated

Question 27

What is molecular systematics?

Answer 27

Determining evolutionary relationships by comparing macromolecules

Question 28

What is a homoplasy?

Answer 28

superficially homologous characteristics, which are actually independently acquired

Question 29

What is a homology?

Answer 29

A structure derived from a recent common ancestor

Question 30

What is a plesiomorphic characteristic?

Answer 30

A shared ancestral characteristic from a distant common ancestor

Question 31

What is a synapamorphic characteristic?

Answer 31

A shared derived characteristic from a more recent common ancestor