Bio Exam 3

What are animals?

What are animals?

motile, multicellular, heterotrophic eukaryotes that feed by ingesting their food

Negative feedback is a method of homeostatic control that

ensures conditions in an organism do not vary too much above or below their set points

What is homeostasis?

The body's automatic tendency to maintain a constant and optimal internal environment

Are most animals diploid or haploid?

diploid and their gametes are produced directly by meiosis

What do animals use for support?

an extracellular matrix because they lack cell walls

Viviparous

a type of embryonic development where the embryo nourished inside a parent and birthed live off spring (eg. humans)

Oviparous

a type of embryonic development where parents lay eggs and offspring is nourished by yolk (ex. chickens)

What is a proteosome?

an organism whose blastospore develops into a mouth

What is a deuterostome?

an organism whose blastospore develops into a anus

What does cleavage mean ?

rapid mitotic cell divisions in the zygote

What phyla’s display protostome development traits?

molluscs, annelids, and arthropods

What phyla’s display deuterostome development traits?

enchinoderms and chordates

What type of cleavage is common in protosomes?

Spiral and Determinate cleavage

What type of cleavage is common in deuterostomes?

radial and indeterminate cleavage

What is a diploblast?

two primary germ layers of blastula (endoderm and ectoderm)

What is a triploblast?

three primary germ layers of blastula (endoderm, mesoderm, and ectoderm)

What is an endoderm?

Intermost cells that form epithelial lining of digestive tract, liver, etc

What is a ectoderm?

cells that remain outside and form nerves, skin, brain, etc

What is a mesoderm?

interna cells that give rise to organs, soft tissues, etc.

What is a coelom?

a body cavity surrounded by the digestive tract that is made up of the mesoderm

Animals with a coelom can only come from

triploblastic organism

What is a pseudocoelom?

a body cavity surrounded by the digestive tract that is made up of the mesoderm AND endoderm

Tripoblasts that have a true coelom are called

coelomates

Tripoblasts that have a pseudocoelom are called

pseudocoelomates

Tripoblasts that lack a coelom are called

acoelomates

Are Basal Eumetazoans diploblastic or triploblastic?

diploblastic

Are Bilateria diploblastic or triploblastic?

tripoblastic

Eumetazoans have

true tissues, nervous and muscle tissue, and radial symmetry

Bilaterians have

bilateral symmetry, complete digestive tract and are triploblastic

What is the significance of a coelom?

1. Fluid cushions the suspended organs

2. Fluid acts like a skeleton against which muscles can work

3. The cavity enables internal organs to grow and move independently of the outer body wall

How many species does phylum Porifera have (sponges)?

5500

What are Poriferans (Overview)?

1. Metazoans (no true tissues) at cellular grade of complexity

2. Asymmetrical

3. Aquatic Marine animals

4. Diploblastic

5. Sessile suspension feeders

6. Has water move through spongocoel to Osculum

7. Has spicules (skeletal elements) in gel like Mesohyl

8. Have 2 cell types: amoebocytes (digestion, distribution of nutrients, construction and reproduction) and choanocytes (power water-vascular system, capture food)

9. Has intracellular digestion

10. sessile

11. Hermaphroditic reproduction (produce with male and female genitalia)

What is an example of a poriferan?

sponge

What type of reproductive systems do poriferans have?

hermaphroditic

Why type of digestion is ONLY seen in poriferans?

intracellular digestion

Are poriferans motile or sessile?

sessile

What do poriferans use to feed on suspended food particles?

choanocytes (flagellated cells that line spongocoel)

What are poriferans feeding mode?

sessile suspension feeders

What tupe of symmetry to poriferans have?

asymmetry

Where do poriferans mainly live?

marine environments

What are Cnidarians (Overview)?

1. Radial Symmetry

2. Diploblastic

3. Eumetazoans with mesoglea (structure that acts as hydrostatic skeleton)

4. Persistent gastrula body plan

5. has a polyp or medusa body form

6. has gastrovascular cavity that utilizes extracellular digestion

7. Capture food containing Cnidocytes containing Nematocysts

8. has a simple radial nerve net that aids in the contraction of the body

9. has asexual and sexual reproduction

10. Critical components on coral reefs (CaCO3)

examples: hydras, jellyfish, etc

What is a cnidarians feeding mode?

they use nematocysts to kill and capture prey

What environments do cnidarians live in?

aquatic

What type of body plan do cnidarians have?

persistent gastrula

What type of reproduction do Cnidarians have?

asexual and sexual

How many species do Cnidarians have?

11,000

What type of symmetry do cnidarians have?

radial

What are Platyhelminthes (Overview)?

1. Bilateral symmetry

2. triploblastic

3. acoelomates

4. unsegmented worms

5. has a gastrovascular cavity shaped in a complex branching pattern

6. Pharynx (opening that acts as mouth an anus)

7. live in terrestrial environments

8. parasites

9. hermaphrodites

examples: flatworms, flukes, tapeworms

What feeding mode do Platyhelminthes have?

pharynx

Why is the gastrovascular cavity of Platyhelminthes important?

increased surface area

What type of body plan do Platyhelminthes have?

dorsoventrally-flattened

What type of symmetry do Platyhelminthes have?

bilateral

What type of coelom do Platyhelminthes have?

acoelom

How many species do Platyhelminthes have?

20,000

What are Arthropods (Overview)?

1. Bilateral symmetry

2. Triploblastic'

3. coelomates

4. open circulatory system

5. have jointed appendages

6. Metamerism - an evolutionary process where segments are duplicated and repurposed

7. has a chitinous exoskeleton (ecdysis aka molting)

8. has a head, thorax, abdomen, hemolymph, Malpighian tubules, compound eyes, and tracheal tubes

9. can sexually reproduce and undergo metamorphosis

What type of symmetry do arthropods have?

bilateral

Where do arthropods live?

everywhere; they can be found in freshwater, marine, and terrestrial habitats, and can even be found living in the air, on the leaves of plants, or in the soil

What are arthropods feeding mode?

they have every feeding mode; carnivores, herbivores, detritus feeders, filter feeders, and parasites; complete digestive tract

How many species do Arthropods have?

1 Million+

What are Chordates (Overview)?

1. have notochord, dorsal, hollow nerve cord (derived from ectoderm) , post anal tail, and pharyngeal slits

2. live in marine environments

3. bilateral symmetry

4. coelomates

5. deuterostomes

What is the function of a post anal tail in Chordates?

tail that is used for movement that extends past the anus

What is the function of a notochord in Chordates?

flexible rod formed from mesoderm that allows for muscle attachment and body movement

What is the function of a dorsal nerve cord in Chordates?

a hollow tube that is formed from the ectoderm

What environment do chordates live in?

marine environment

What are the functions of pharyngeal structures in Chordates?

1. Suspension-feeding early

2. Gas exchange in jawless vertebrates

3. Gills and jaws in gnathostomes

4. Develop into parts of the ear, head, and neck in tetrapods

How many species do chordates have?

60,000

How many species do Cephalochordates have?

23

What type of feeding mode do Cephalochordates have?

via pharngeal slits

An example of a Cephalochordate is a

lancelet

What is the function of a cirri in Cephalochordates?

used to as an entrance for food and to filter larger food particles

What is the function of an atriopore in Cephalochordates?

where water exits the body

What is the function of myomeres in Cephalochordates?

blocks of skeletal muscle tissue; w or V shaped muscle fibers

How many species do urochordates have?

2,000

What type of feeders are urochordates?

suspension feeders

Where do urochordates live?

marine environments

What is an example of urochordates?

sea squirts

What tissues come from the ectoderm and endoderm?

epithelial tissues

What does homeotherms mean?

organisms that maintain constant body temp regardless of environmental conditions

What does poikilotherms mean?

an organisms varied body temp based on environments

What causes an organism to lose heat?

convection and evaporation

What causes an organism to gain heat?

radiation and conduction

Phylogeny Tree

What are ecdysozoans?

animals that shed a cuticle (a tough external coat) as they grow