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Digestive organs, circulatory system, and nerve cords are completely absent in

Ectoprocta

Platyhelminthes

Porifera

Mollusca

Annelida

Due in great part to its characteristic of having a fixed number of cells in the adult, Caenorhabditis elegans has become an important model research organism in developmental biology. To which phylum does C. elegans belong?

Annelida

Nematoda

Platyhelminthes

Arthropoda

Nemertea

A lophophore is a structure used by lophophorates for

sensory reception

respiration

feeding

locomotion

structural support

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Deanna Hettinger
Deanna HettingerLv2
28 Sep 2019
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Related questions

QUESTION 1

The “Cambrian Explosion” describes the relatively sudden appearance of __________ in the fossil record in the Cambrian.

Metazoans

Eukaryotes

Algae

Cephalopods

Chocolate

0.5 points

QUESTION 2

Poriferans lack:

Extracellular matrix

Organs

Choanocytes

Nuclei

0.5 points

QUESTION 3

Which of the following has no terrestrial species?

Brachiopoda

Nematoda

Mollusca

Arthropoda

0.5 points

QUESTION 4

The metazoan phylum with the greatest diversity (i.e., number of species) today is:

Arthropoda.

Annelida.

Cnidaria.

Mollusca.

0.5 points

QUESTION 5

Segmentation is a feature of:

Cnidarians

Platyhelminthes

Nematodes

Annelids

0.5 points

QUESTION 6

A coelom is:

Fun for the whole family.

A fluid-filled body cavity forming within the mesoderm.

A stinging cell found in cnidarians.

A characteristic of flatworms.

A fluid-filled body cavity between the mesoderm and endoderm.

0.5 points

QUESTION 7

How old is the earliest fossil evidence of life?

3.8 Ma

3.8 Ga

1.8 Ga

543 Ma

0.5 points

QUESTION 8

Which of the following is found only in bilaterians?

Mesoderm

Choanocytes

Radial symmetry

Gastrulation

Nougat

0.5 points

QUESTION 9

Which of the following is not an explanation put forward for the Cambrian Explosion?

Oxygen increase

Revolution in substrate use

Predation

Global warming

0.5 points

QUESTION 10

Cnidarians are distinct from other animals in having:

A can-do attitude

Nematocysts

Chitin

Collagen

Bilateral symmetry

0.5 points

QUESTION 11

Which of the following is a group within Platyhelminthes?

Insecta

Velveeta

Bivalvia

Cestoda

Hydrozoa

0.5 points

QUESTION 12

Of Fungi, Metazoa, and Plantae, which two are thought to be more closely related to each other than they are to the third?

Metazoa and Plantae

Fungi and Plantae

Fungi and Metazoa

0.5 points

QUESTION 13

The Cryogenian is a period of the Proterozoic characterized by:

Low self esteem

Earliest fossils of life

Cooling and glaciation

Sudden appearance of fossils with hard parts

Increase in oxygen

0.5 points

QUESTION 14

Which of the following is thought not to have been abundant in the environment of the early Earth when life originated?

Oxygen

Nitrogen

Methane

Water

0.5 points

QUESTION 15

Of Archaea, Bacteria, and Eukarya, which two are thought to be more closely related to each other than they are to the third?

Bacteria and Eukarya

Archaea and Bacteria

Archaea and Eukarya

0.5 points

QUESTION 16

The increase in oxygen that occurred around 2.3 Ga is referred to as:

The Snowball Earth

The Permian Extinction

The Cambrian Explosion

The Great Oxidation Event

Friday

0.5 points

QUESTION 17

A lophophore is:

A feeding structure found in brachiopods and bryozoans.

A reproductive structure found in annelids and molluscs.

A photoautotroph.

Available at Target™.

Absent in all lophotrochozoans.

0.5 points

QUESTION 18

One of the main divisions of protostomes is:

Electronica

Cnidaria

Eukarya

Lophotrochozoa

Deuterostomia

0.5 points

QUESTION 19

If, as some studies have suggested, Ctenophora is the sister-taxon to other metazoans, this would imply that:

Poriferans are not animals.

Cnidarians are not monophyletic.

We are all hosed.

Nervous systems evolved more than once, or were lost by Porifera.

Ctenophorans are cnidarians.

0.5 points

QUESTION 20

The chambered shells of fossil cephalopods contribute to:

Feeding.

The Red Cross.

Respiration.

Control of buoyancy.

Propulsion.

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