Question

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.

Answer 1

Q 1. Metazoans. From phyligenetic ananlysis it was observed that during the Cambrian explosion, metazoans (multi-celled animals) evolved monophyletically from a single common ancestor, flagellated protists.

Q 2. Organs. Sponges lack organs and also tissue, and all the cells exhibit considerable independence. The sponge is made up of two single-cell-deep layers and an intermediate mesohyl (mobile cells plus extracellular matrix). The outer (sac) layer consists of flattened polygonal cells called pinacocytes. The middle (mesohyl) layer consists of gelatinous protein/carbohydrate material, and a skeleton of calcareous or siliceous spicules, or of elastic proteinaceous fibers called spongin fibers. The inner layer consists of flagelled cells called collar cells, or choanocytes.

Q 3. Brachiopoda has no terrestrial species, As Arthropoda, Nematoda and Mollusca 80 % of the species are terrestrial species.

Q4. Arthropoda. Among invertebrates, arthropods (insects, crustaceans, spiders and relatives) are by far the most diverse group with more than 1.2 million living species.

Q5. Annelida. Body elongate and composed of many segments, each segment with fine bristle like setae for locomotion

Q6. A coelom is a fluid-filled body cavity that is completely lined by tissue created from the mesoderm, the middle layer of the primary cells found in an embryo. It is typically found in multicellular organisms, which are living things that have more than one cell.

Q7. 3.8Ga

Q8. Mesoderm

Q10. A can do attitude

Q11. Cestoda

Q12. Fungi and Plantae

Q15. Archea and Bacteria

Q17 A feeding structure found in brachiopods and bryozoans