How does one define an animal?

What nutritional adaptation do animals use?

- We need characteristics that describe the vast majority of animals and sufficiently defines the group. 

- All animals are heterotrophs. Must consume other organisms to gain energy. Can't make their own food. 

CELL STRUCTURE AND SPECIALIZATION

Animals are __ __. 

Their cells lack __ __. The __ __ comes from something else. 

Their bodies are held together by __. What is this?

All cells have __ functions.

multicellular eukaryotes

cell walls, support structure

collagen, which is a type of protein.

specialized functions

REPRODUCTION AND DEVELOPMENT

How do most animals reproduce? 

__ stage usually dominating the life cycle.

sexually

diploid

What are Hox genes? 

__ of these genes can create a __ __, or development.

Hox genes are genes in which only animals have. They regulate the development of body form.

can produce a wide diversity of animal morphology.

Manipulation, diverse morphology.

GEOLOGICHISTORY

How old are animals? 

What is the common ancestor of living animals?

There is no exact answer to how old animals are but as of now, the oldest animal is marked to be 625 million years old. 

common ancestor - choanoflagellates - was probably itself a colonial, flagellated protist.

Paleozoic Era (542-251 MYA)

What do the animals look like? 

- The __ explosion: marks the __ __ of many major groups of living animals.

What are 3 of the several current hypotheses concerning the fast evolution of animals? 

They look foreign. Not like modern animals.

Cambrian, earliest appearance. 

1. predator-prey interactions - increasing competition is causing evolution to speed up.

2. atmospheric oxygen - O2 itself will change DNA of animals because it is a mutagen. 

3. Hox genes - causes rapid development of animals which causes rapid evolution

Mesozoic Era (251 - 65.5 MYA)

What do the animals look like? 

__ of lineages

__ life dominated by several forms of __. 

animals look more normal. Jurassic era also part of this era. 

diversification 

terrestrial, vertebrates

Cenozoic Era (65.5 MYA to present)

This is the __ era. 

Terrestrial dominated by __ and __.

Change in dominance often precipitated by __ __.

modern

birds, mammals

mass extinctions

In order to classify animals we need to develop __ that all animals have and we can __. 

The more __ that organisms share the more __ they are.

What two types of characteristics can we use?

characteristics, compare.

charaters, related.

morphological and molecular/genetic (DNA, RNA, etc.)

domain

kingdom

phylum

class

order

family

genus

species

the second way we present evolutionary relationships is with __ __. 

The distance determines the __ between organisms.

phylogenetic trees.

relativity

CLASSIFICATION OF BODY PLAN

What is a way that zoologists categorize the diversity of animals? 

"these" charaters include what four characteristics?

body plan - grade. 

1. symmetry

2. tissue

3. body cavity

4. development 

SYMMETRY 

What are the two types of symmetry in Animalia?

Describe what these are.

Radial symmetry - The organism can be cut in half multiple times. 

Bilateral symmetry - organism can be only cut in half once. 

SYMMETRY continued

What are the parts of the animal's bilateral symmetry called? 

What is cephalization? 

dorsal (top), ventral (bottom)

right and left side 

anterior (head), posterior (tail)

Cephalization is the development of a head.

TISSUES

What are tissues?

Animal embryos form __ layers, __ tissues including __, __, and __. 

What is it called to have 2 germ layers? 3 germ layers? 

tissues are collections of specialized celles isolated from other tissues by membranous layers. 

germ, embryonic, ectoderm, endoderm, and mesoderm. 

Diploblastic, triploblastic.

BODY CAVITY 

The presence and complexity of a __ __ can also be used to organize animals into __. This means it can determine who is related to who.

What is it called to have a body cavity? 

What are organisms without body cavities called?

body cavity, grades.

coelom

acoelomates

PSEUDOCOELOMATES

what is this? 

COELOMATES

what are these? 

have a true body cavity. these are the most common. 

is called a coelom and is derived from mesoderm. 

DEVELOPMENT

We classify animals by __ in development. 

what are the two development modes? 

patterns.

protostome and deuterostome

CLEAVAGE

In protostome development cleavage is __ and __.

In deuterostome development cleavage is __ and __. 

spiral, determinate

radial, indeterminate

COELOM FORMATION

what is protosome development? 

what is deuterostome development? 

protosome - the splitting of initially solid masses of mesoderm to form the coelomic cavity is called schizocoelous development 

deuterostome - formation of the body cavity is described as enterocoelous development

FATE OF THE BLASTOPORE

in protostome development - the blastopore becomes the __. 

in deuterostome development - the blastopore becomes the __. 

Zoologists currently recognize about __ animal phyla. 

there is __ on the relationships among phyla

there is two __ hypotheses.

what are these two hypotheses?

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disagreement. phylogenetic.

a morphology hypothesis: based on morphological and developmental comparisons.

molecular hypothesis: based on molecular data

POINTS OF AGREEMENT

all animals share a common ancestor: __. 

sponges are __. 

__ is a clade of animals with __ tissues.

most animal phyla belong to the clade __. 

vertebrates and some other phyla belong to the clade __. 

monophyletic

basal

eumetazoa, true.

bilateria, deuterostomia.

DISAGREEMENT OVER THE BILATERIANS

The morphology-based tree: divides the bilaterians into what two clades? 

in contrast, serveral recent molecular studies.. generally assign two siter taxa to the protostomes rather than one:the __ and __.

the two clades are deuterostomes and protostomes.

exdysozoans, lophotrochozoans.