Bio Exam 2

Nearly all animals reproduce

asexually

All animal cell adults are

diploid

3 Types of Body Symmetry

Cnidaria, Parazora, Bilateria

Cnidaria Symmetry

Radial

Parazoa Symmetry

None

Bilaterial Symmetry

Bilateral

Broad Differences in Animal Phyla

Symmetry, Germ Layers, Features of Embryonic Development

Blastula

Zygote divides by mitosis to form a hollow bal of cells

Endoderm

Forms a lining of the future digestive tract

Ectoderm

Forms an outer layer that will give rise to the skin and nervous system

Mesoderm

Forms a middle layer that will give rise to muscles and most internal organs

Diploblastic

Two Layers

Triploblastic

Three Layers (most animals)

Protosome

Mouth Form First

Dueterostome

Anus forms first

Blastopore

opening formed from the endoderm during gastrulation

Body Cavity

Space that houses internal organs

Coelomates

True body cavity

Pseudocoelomates

Coelom is not completely lined with tissue

Acoelomates

Lack a fluid filled cavity

Coelom

Fluid filled body cavity

Segmentation

body is divided into regions called segements

Reason behind animal diversification

increasing complex predator-prey relationships and/or an increase in atmospheric ozygen

Animal diversified rapidly around

530 millions years ago during the “Cambrian Explosion”

96% of animals are

invertebrates

Spongocoel

Central cavity that water is drawn into

Osculum

Large opening at the top of sponges

Choanocytes

specialized cells in sponges that trap and eat small particulate matter in the spongocoel

Sponges reproduces

both sexually and asexually

Most Cnidarians exists in

sessile polyp or motil medusa

Motile Medusa

Movement

Sessile Polyp

Stationary

Phylum Cnidaria Symmetry

Radial

Cnidocytes

In cnidarians which function in defense or capture of prey

Cnidocytes contain

nematocysts

Nematocysts

powerful capsules with an inverted coil and barned thread

Cnidocil

Hair like structures that detect chemical stimulus and lead to discharge of the nematocyst

Phylum Platyhelminthes Layers

Triploblastic

Phylum Platyhelminthes Features

Lack coelom (acoelomates)

One opening for mouth and anus

Bilaterally symmetrical

asexual or sexual

Coronoa

Cilitated crown found Phylum Rotifera

Phylum Rotifera Features

Separate opening for mouth and anus

Mastax

Pseudocoelomates

Parthenogensis

Mastax

Mouth opens into a circular muscular pharynx

Phylum Mollusca Body Plan

Muscular Foot

Visceral Mass

Mantle

Mantle

Secretes a shell

Visceral Mass

Contains internal organs

Phylum Mollusca Features

Coelomates

Hemolymph

Metanephridia

Radula

Hemolymph

Fluid pumped in from the open circulatory system

Metanephridia

Excretory organ that removes nitrogenous and other waste

Radula

Tongue-like organ that is used for eating plants or boring into shells of other species

Phylum Annelida

Consist of segmented worms

Phylum Annelida Advantages

If components of one segments fails, others still function n

Muscle contractions are minimized in segmented animals allowing for effective locomotion over solids

Some segemnts have specialized function

Phylum Annelida Features

Setae

Advanced Nervous System

Closed Circulatory System

Respiration → skins surface (moist environments)

Digestive system has specialized regions

Setae

Chitinous bristles

Parapodia

May be found in setae that are fleshy, footlike, and help with movement

Phylum Nematoda

Roundworms

Phylum Nematoda Features

All habitats, some parasitic

Cuticle made of collagen

Psuedocoelomates

Complete digestive system

Sexual repro, fertilization internally

Phylum Arthopoda Features

Most diverse

Exoskeleton, segmentation, jointed appendages

Hard cuticle

Phylum Arthropoda exoskeleton composition

chitin and protein

Jointed appendages permit

complex movements and functions

Phylum Arthopoda Body Plan

Head → Thorax → Abdomen

Ommatidia

Open circulatory system, hemolymph

Feathery Gills (aquatic_

Tracheal System (Terrestrial arthropods)

Complex digestive system

Ommatidia

Compound eyes composed of independent visual units

Phylum Echinodermata Symmetry

Radial (only in adults) + Bilateral (free swimming larvae)

Phylum Echinodermata Features

No brain, simple nervous system

Coelomates, portion adpated into water vascular system

Tiny Tube Feet

Tiny Tube Feet Function

movement, gas exchange, feeding excretion

Phylum Chordata Critical Innovations

Notochord

Dorsal Hollow Nerve Cord

Pharyngeal Slits

Postanal Tail

Notochord

single flexible rod that lies between the digestive tract and nerve cord

provides skeletal support

Dorsal Hollow Nerve Cord

Sold tube ventral to alimentary canal

In vertebrates develops into brain and spinal cord

Pharyngeal Slits

Close to the mouth where water enters and exits through slits

Filter-feeding device and may develop gills for gas exchange

Postanal Tail

Used for locomotion

Vertebrates Additional Traits

Vertebral Column (instead of notochord), Cranium, Endoskeleton

Cyclostomes

“Circle mouths” no jaws

Hagfish

Marine cylostomes that lack eyes, jaws, fins, and even vertebrae

Lampreys

lack hinged jaw and true appendages

Gnathostomes

Jawed vertebrates

Hinged jaw evolution

gill arches, cartilaginous or bony rods

Chondricthyans

Cartilaginous FIsh

Osteoichthyans

Bony Fish (actinopterygii and sarcopterygii)

Tikataalik Rosae

Intermediate state between an ancestral form (tetrapods) and descendants (fish)

Amphibians Characteristics

Buccal pumping

Skin can absorb O₂

3 Chamber Heart

Amphibians Problem

Descciation (skin drying out)

Amniotic Egg 4 separate extraembyronic membranes

Amnion

Yolk Sac

Allantois

Chorion

Amnio

protects embryo

Allantois

Disposal sac for waste

Chorion

Gas exchange between embryo and air

Additional Adaptations for Amniotes

Desiccation-resistant skin

Thoracic Breathing

Water conserving kidneys

Internal fert

Ectothermic

absorbing external heat (reptile)

Birds major adaption

feathers for flying

Adaptation for Birds

Feathers

Air sacs

Reduction of organs

lightweight bones

Mammals Distinct Characteristics

Mammary glands

Hair

Specialized Teeth

Enlarged Skull

Monotremes

egg laying mammals

Eutherians

mammals that bear fully developed live young

Tissue

Association of many cells that have a similar structure and function

Tissue Types

Muscle

Nervous

Epithelial

Connective

Muscle Tissue

cells specialized to absorbed, or contract, generating mechanical forces

Epithelial Tissue

sheets of densely packed cells that cover the body or individual organs and line the interior of various cavities

Connectie Tissue

surround, anchor, connect, and support

Organ

two or more kinds of tissue arranged in various proportion

Surface Area/Volume Ratio

Relationship between structures surface and volume

Ideal SA/V ratio

High for exchange of heat