CH 33

tapeworms

most live in vertebrates' intestines

Diploblastic and triploblastic animals

diploblastic have two germ layers (endoderm and ectoderm) and triploblastic have three germ layers (endoderm, mesoderm, and ectoderm)

True or false: Nematocysts are the most complex structures secreted by single animal cells. A) true B) false

A) true

protostomes

undergo spiral cleavage; animals in which the mouth develops from the blastopore and the anus develops from the second opening

sponge (Porifera)

water enters through the ostia into the spongocoel and exits via the osculum; fertilization occurs in mesohyl Consider: Porifera and Cnidaria have similar body plans that include spongocoel:gastrovascular cavity; mesohyl:mesoglea; osculum:mouth/anus; epithelial cells:epidermis.

animals

while eukaryotic cells appeared ~2.5 billion years ago, bilateral invertebrates didn't appear until ~590 million years ago; suggested ancestor was choanoflagellates; are monophyletic; their cells lack rigid cell walls and are flexible; they can move more rapidly and in more complex ways than members in other eukaryotic kingdoms; they develop from a zygote in a characteristic embryonic development; and their millions of species show great diversity in size, form, structure, and habitat.

indeterminate cleavage

allows development of a complete embryo from each of the cells harvested from an 8 cell embryo Consider: Indeterminate cleavage is seen in deuterstomes while protostomes have determinate cleavage.

Chordate

animal with notochord , dorsal hollow nerve cord, pharyngeal slits, post anal tail (these traits occur at some point during development)

invertebrates

animals that lack a vertebral column

phylum Platyhelminthes

are acoelomate; are tripoblastic; have an imcomplete digestive system, and respire by diffusion of gases through the body wall Consider: Some of these are parasites.

rotifers

are bilaterally symmetrical, have a corona as food gathering organ, have a complete gut with mouth and anus, undergo parthenogenesis, and most occur in fresh water

annelid body

contains separate segments with septa partitions; muscles to swim, crawl, and burrow, ganglia to respond to light and respond to other environmental cues, circulatory, excretory, and neural elements in each segment, and setae (chitin bristles) in each segment.

flukes

parasitic worms with larval stage living in snails

Cephalization is

the concentration of sense organs, nervous control, etc., at the anterior end of the body,

Bilateria are characterized by

A plane of symmetry that forms mirror images around a vertical plane in the midline.

Compare pseudocoelom and coelom

A pseudoceolom has outer layer of mesoderm and inner layer of endoderm, A coelom is completely enclosed by mesoderm

What has recent molecular data revealed about the phylum Porifera? A) It is monophyletic. B) It is comprised of 2 or 3 distantly related groups. C) It is not an animal phylum. D) Molecular data supported what had been the minority view that the phylum Porifera is monophyletic. E) None of the choices are correct.

A) It is monophyletic.

Which of these is NOT a feature common to all animals? A) locomotion B) multicellularity C) heterotrophic D) lack of a cell wall E) specialized tissues

A) locomotion

With which of the following are arthropods now grouped? A) protostomes that molt their cuticles at least once during their life B) annelids C) sponges D) cnidarians E) ctenoophores

A) protostomes that molt their cuticles at least once during their life

Which of the following is characteristic of sponges? A) symmetry B) sexual reproduction C) tissues D) organs E) adult mobility

A) symmetry

Recent molecular data has led to a revision of the traditional classification of animal phyla. The annelids and arthropods are now moved into different clades, and the arthropods are now assigned to ________, animals that molt. A) Ctenophora B) Ecdysozoa C) Chaetognatha D) Nematoda E) Echinoderms

B) Ecdysozoa

Match the type of heterotroph with food source. A) Detritivores consume autotrophs. B) Herbivores consume autotrophs. C) Carnivores consume autotrophs. D) None of the choices are correct.

B) Herbivores consume autotrophs.

Select the correct set of attributes for deuterostomes. A) indeterminate development; humans; blastopore becomes anus B) determinate development; echinoderms; blastopore become anus C) radial cleavage; echinoderms; blastopore becomes mouth D) spiral cleavage; humans; blastopore becomes mouth

B) determinate development; echinoderms; blastopore become anus

What do deuterostomes NOT include? A) chordates B) ecdysozoans C) echinoderms D) sea stars E) sea urchins

B) ecdysozoans

What is thought to have been the key innovation that fostered diversification in animals? A) cephalization B) specialized tissues C) coeloms D) closed circulatory systems. E) bilateral symmetry

B) specialized tissues

Select the correct array of defining features for protostomes. A) radial cleavage/ indeterminate development/blastopore forms anus/coelom from invagination of archenteron B) spiral cleavage/determinate development/blastopore forms mouth/coelom from mesodermal split C) radial cleavage/determinate development/blastopore forms mouth/coelom from mesodermal split D) spiral cleavage/determinate development/blastopore forms anus/coelom from mesodermal split E) spiral cleavage/indeterminate development/blastopore forms anus/coelom from mesodermal split

B) spiral cleavage/determinate development/blastopore forms mouth/coelom from mesodermal split

Bilateria and Radiata

Bilateria are characterized by a plane of symmetry that forms mirror images around a vertical plane in the midline; Radiata are characterized with radial symmetry

The innovation of segmentation allowed for redundant systems and what other important improvement? A) hydration B) meiosis C) locomotion D) reproductive success E) vision

C) locomotion

Sponge cells are able to dedifferentiate and then redifferentiate. All other animals differentiate irreversibly. What does this suggest? A) sponge cells behave like plant cells B) sponge cells behave like fungi cells C) the evolution of specialized tissues may be a key innovation D) evolution failed to develop a powerful innovation

C) the evolution of specialized tissues may be a key innovation

The putative ancestor of animals was

Choanoflagellates

What innovation made possible the development of advanced organ systems? A) open circulatory system B) closed circulatory system C) digestive cavity D) body cavity isolated from the exterior of the animal E) germ layers

D) body cavity isolated from the exterior of the animal

Which of these is NOT a protostome? A) spiralians B) ecdysozoans C) lophotrochozoa D) echinodermata E) platyzoa

D) echinodermata

Select the correct statement concerning embryonic development. A) Zygotes are formed from the fusion of haploid gametes. B) Zygotes undergo mitotic divisions called cleavage. C) Cleavage produces a ball of cells called a blastula. D) The blastula folds inward to form a hollow sac with an opening called a blastopore, a developmental stage called a gastrula. E) All choices are correct.

E) All choices are correct.

Select the correct statement concerning segmentation. A) mediated at the molecular level by Hox genes B) allowed for redundant systems C) allowed for improved locomotion. D) allows that damage to any one segment need not be fatal because other segments duplicate the damaged segment's functions. E) All choices are correct.

E) All choices are correct.

Which of the following is a defining characteristic of an animal? A) multicellularity B) heterotrophic C) no cell walls D) sexual reproduction E) All choices are defining characteristics.

E) All choices are defining characteristics.

Which of the following is NOT a key innovation in animal evolution? A) evolution of symmetry B) evolution of tissues, allowing specialized structures and functions C) evolution of a body cavity D) evolution of various patterns of embryonic development E) All choices are key innovations in animal evolution.

E) All choices are key innovations in animal evolution.

A(n) _____ is an example of a specialized organ system that assists with distribution of nutrients and removal of wastes. A) flagella B) excretory system C) coelom D) pseudocoelom E) circulatory system

E) circulatory system

On the state of what did morphology-based phylogeny focus? A) germ layers B) segmentation C) molting D) coelom E) symmetry

E) symmetry

Tripoblastic are animals that

Have three germ layers (Ectoderm, mesoderm, endoderm)

dominant animal phyla on land

Mollusca, Arthropoda (phyla with the greatest number of species), Chordata

Parazoa and Eumetazoa

Parazoa lack symmetry, have no specialized tissues or organs; Eumetazoa have symmetry and more than one type of tissue and organs

Ectoderm

The ectoderm will form the nervous system, the epithelial cells of mammary glands, the lens of the eyes, hair, pigment cells and the epidermis of the skin.

The fate of the embryonic germ layers is

The endoderm forms the gut, the ectoderm forms the epidermis and part of the nervous system, and the mesoderm forms muscles and most internal organs

Mesoderm

The mesoderm will form skeletal muscle, smooth muscle, the heart, blood vessels, blood cells, kidney, spleen, fat cells, the skeleton, most connective tissues and most of the urogenital system.

open circulatory system vs/ closed circulatory system

The open circulatory system has a combination of blood vessels and large thin-walled sinuses whereas a closed circulatory system has only vessels

arthropods

are coelomates; insects are most successful class with greatest number of species; undergo metamorphosis as they develop through stages from egg to adult; ecdysis is the process of molting; move through muscles working against exoskeleton (protection against predators, impedes water loss, and acts as muscle attachment points), trachea for oxygen diffusion into tissues Consider: Jointed appendages is the evolutionary innovation that first appeared in arthropods.

complete metamorphosis

change of a larval form of insect to a different adult form

Compound eyes

composed of independent visual units called ommatidia

cephalization

concentration of sensory organs on the anterior end of the body

germ layers

embryonic layers that have different developmental potentials Consider: The endoderm forms the gut, the ectoderm forms part of the nervous system and the epidermis, and the mesoderm forms muscles and most internal organs.

deuterostome

evolved from protostomes; triploblastic; dividing cells on a radius from the polar axis; are bilateral symmetrical; blastopore becomes anus and mouth develops later; indeterminate development meaning any cell from embryo (up to 8 cell embryo) can develop into a complete organism; are coelomates with coelom produced by invagination of archenteron

Cnidaria

first marine animal phylum to evolve symmetrical body plans; widespread in shallow warm temperature waters, gelatinous Consider: Bilateral symmetry in animals included anterior and posterior body areas, greater efficiency in movement, two mirror images in body plan, greater efficiency in seeking food and mates. Acoelomates have no body cavity.; Coelomates have a fluid filled cavity that develops entirely within the mesoderm.in composition, exist as polyps or medusae, contain cnidocytes containing nematocysts

typical animal embryonic development

follows path of zygote --> morula --> blastula --> gastrula

segmentation

found in Arthropoda, Annelida, Chordata

hermaphrodite

individual animal that can produce both sperm and eggs

Endoderm

innermost germ layer; develops into the linings of the digestive tract and much of the respiratory system. The endoderm will form the entire epithelial lining of the gastrointestinal tract, as well as the liver, pancreas, gall bladder, thyroid, the epithelial lining of the trachea and the respiratory surface of the lungs.

coelom evolution

led to hydrostatic skeleton development; that led to circulatory system solving problem of barrier to diffusion created by gut Consider: Coelomates are animals with a true coelom. A true coelom is completely enclosed by mesoderm whereas a pseudocoelom has an outer layer of mesoderm and an inner one of endoderm. An acoelomate is an animal with neither a coelom nor a pseudocoelom.surrounded by tissue

mollusca

phylum that includes snails (land dwelling), clams, oysters, and octopuses; the mantle are the folds of tissue that arise from the dorsal body wall and enclose a cavity surrounding the visceral mass (modified mantle allows squids and octopuses to move); the lophophore functions as a surface for gas exchange, location of the radula, a rasping, food-collecting organ, a means of attachment to the substrate, and location for the tentacles and the anus. Consider: An animal that is attached to the substrate and cannot move is said to sessile.

animal evolutionary transitions

radial to bilateral symmetry; no body cavity to body cavity; unsegmented to segmented bodies, and protostome to deuterostome development

parthenogenesis

reproduction by way of diploid females laying diploid eggs that hatch into diploid females

cephalopods

some are intelligent, some have shells, some are very large, and all are predatory and have a closed circulatory system

choanocytes

specialized flagellated cells in sponges whose beating drives water through body and whose collar extracts food from the water (characteristics seen previously in choanoflagellates) Consider: Sponges have free-swimming larvae; sessile adults, lack of specialized tissues and organs, and a lack of symmetry (may be radial in small species).

nephridia

structure that removes nitrogenous wastes in mollusks