Deck 41: Echinoderms and Chordates

Question 1

Echinoderms and chordates are significantly different to all other animal phyla because

A) of their very unusual skin covering.
B) they evolved much later than the others.
C) of their pattern of embryonic development.
D) they have an internal skeleton and notochord.
E) they contain species that are much larger.

Answer 1

of their pattern of embryonic development.

Question 2

Embryonic development in echinoderms and chordates is characterised by the

A) blastopore developing as an anus.
B) blastopore developing as a mouth.
C) development of a single layered blastula.
D) presence of extra embryonic membranes.
E) formation of a trochophore larva.

Answer 2

blastopore developing as an anus.

Question 3

Which of these statements about echinoderms is CORRECT?

A) The skeleton of echinoderms is ectodermal in origin.
B) Feather stars belong to the class Echinoidea.
C) Echinoderms are unsegmented.
D) Echinoderm embryos develop into a trochophore larvae.
E) Some echinoderms are colonial.

Answer 3

Echinoderms are unsegmented.

Question 4

Although echinoderms appear to have radial symmetry, their bilateral origins are revealed by

A) the shape of their water vascular system.
B) the symmetry of their larvae.
C) the development of an oral/aboral surface.
D) their baso-lateral anatomy.
E) their five-rayed symmetry.

Question 5

When the spicules of an echinoderm are sutured together to form a rigid skeleton, the resulting structure is known as

A) a test.
B) an ossicle.
C) a madreporite.
D) a pedicellariae.
E) a spine.

Question 6

The water vascular system is

A) coelomic in origin.
B) unique to echinoderms.
C) lined with cilia.
D) required for locomotion.
E) All of the answers are correct.

Question 7

The tube feet in echinoderms are extended by forcing water into them from the

A) madreporite.
B) ring canal.
C) radial canal.
D) ampullae.
E) mouth.

Question 8

Excretion of nitrogenous wastes in Echinoderms is via

A) tube feet.
B) nephridia.
C) the madreporite.
D) tube feet and nephridia.
E) tube feet and the madreporite.

Question 9

The earliest larval stage of echinoderms

A) is called the dipleurula larva in approximately half of all living species.
B) is called a trochophore larva.
C) is radially symmetrical.
D) develops projecting arms.
E) does not have a through gut, with a mouth and anus.

Question 10

Chordates are so named because of their

A) dorsal notochord.
B) ventral nerve cord.
C) hollow dorsal nerve cord.
D) dorsal notochord and ventral nerve cord.
E) dorsal notochord and hollow dorsal nerve cord.

Question 11

At some stage of development, chordates possess

A) pharyngeal slits.
B) a hollow dorsal nerve cord.
C) a notochord.
D) pharyngeal slits and a hollow dorsal nerve cord.
E) All of the answers are correct.

Question 12

A structure found in lancelets (cephalochordates) but not in tunicates (urochordates) is

A) a vertebral column.
B) a notochord.
C) a hollow dorsal nerve cord.
D) the vascular system.
E) blocks of muscle for movement.

Question 13

All craniates have

A) a distinct head with a cranium.
B) a backbone composed of vertebrae.
C) dermal bones.
D) a bony head.
E) All of the answers are correct.

Question 14

Vertebrae

A) are characteristic of all chordates.
B) are the segmental divisions of the notochord.
C) surround and replace the notochord during embryonic development.
D) do not occur in gnathostomes.
E) have ventral projections that surround and protect the nerve cord.

Question 15

Jawed vertebrates have jaws derived from

A) dermal bones.
B) unfused cranial bones.
C) anterior branchial arches of the gill.
D) bones of the inner ear.
E) the notochord during embryonic development.

Question 16

Many features unique to vertebrates develop from an embryonic tissue called the

A) dorsal lip of the blastopore.
B) neural crest.
C) endoderm.
D) ectoderm.
E) blastocoel.

Question 17

Fishes are divided into two classes, Chondrichthyes and Osteichthyes, on the basis of

A) the chemical composition of the skeleton.
B) the structure of the jaw.
C) the structure and function of their fins.
D) their mode of reproduction.
E) the structure of the teeth.

Question 18

The bony fishes (Osteichthyes) are divided into two subclasses, Actinopterygii and Sarcopterygii, on the basis of

A) the chemical composition of the skeleton.
B) the structure of the jaw.
C) the structure and function of their fins.
D) the presence of a swim bladder.
E) their mode of reproduction.

Question 19

The limbs of tetrapods (amphibians, birds, reptiles and mammals) are

A) similar to the fins of sharks and rays.
B) similar to the fins of ray-finned fish.
C) similar to the fins of lobe-finned fish.
D) similar to the fins of cartilaginous fish.
E) not similar to any of these.

Question 20

Lungfishes and amphibians are similar in that

A) they are totally aquatic.
B) gastrulation produces a yolk plug.
C) they both have the ability to burrow.
D) they both have lungs which are their only means of gas exchange.
E) None of the answers are correct.

Question 21

Most amphibians return to water to lay their eggs because

A) the egg lacks an amniotic membrane.
B) water is isotonic with their egg fluids.
C) amphibians need water to mate.
D) embryos rapidly dry out as they do not have a covering.
E) fertilisation is external.

Question 22

Amphibians are not amniotes because

A) the whole zygote contributes to the structures of the embryo.
B) the zygote does not produce numerous extra-embryonic membranes.
C) fertilisation in amphibians is internal.
D) the whole zygote contributes to the structures of the embryo and the zygote does not produce numerous extra-embryonic membranes.
E) the whole zygote contributes to the structures of the embryo and fertilisation in amphibians is internal.

Question 23

In amniote tetrapods

A) metamorphosis is absent.
B) cleavage is meroblastic.
C) there is only one sacral vertebra.
D) metamorphosis is absent and cleavage is meroblastic.
E) metamorphosis is absent and there is only one sacral vertebra.

Question 24

Reptiles are not considered a monophyletic group. This means that

A) not all reptiles have an amnion.
B) reptiles have different evolutionary origins.
C) reptiles live in diverse environments.
D) reptiles are very diverse in structure.
E) birds as well as reptiles should be classified together.

Question 25

Mammals are the only animals that

A) always bear their young alive.
B) have a four-chambered heart.
C) feed their young with body secretions from a mammary gland.
D) have bicuspid teeth.
E) have two condyles on the skull to articulate with the vertebral column.

Question 26

The marsupials and eutherians are separated according to

A) length of gestation.
B) relative length of lactation.
C) presence or absence of a placenta.
D) birth of live young.
E) method of fertilisation.

Question 27

Primates can be classified into two groups based on

A) nasal construction.
B) number of teeth cusps.
C) the presence of a prehensile tail.
D) size of the head.
E) degree of maternal care.

Question 28

Which of the following is NOT a primate characteristic?

A) A well-developed clavicle
B) Prehensile digits
C) Monocular vision
D) Relatively large brain
E) Plantigrade limbs

Question 29

Currently, the oldest genus to be classed as 'hominid' is

A) Paranthropus.
B) Australopithecus.
C) Homo.
D) Proteopithecus.
E) Sahelanthropus.

Question 30

An exact relationship between the many hominid fossil finds is still unclear and is subject to disputed interpretation. However, it is widely accepted that

A) Homo sapiens is the only hominid species to have evolved.
B) there have been several other species in the genus Homo.
C) language clearly separates humans from the other hominids.
D) Homo sapiens most likely evolved from Homo neanderthalensis.
E) only one hominid species lived at any one time.

Question 31

The pharyngeal slits of early chordates were modified through evolution to provide a range of functions including

A) gills.
B) gas exchange.
C) vocalisation.
D) hearing.
E) All of the answers are correct.

Question 32

Echinodems

A) have larvae that are radially symmetrical and free-swimming.
B) are marine animals that have a five-rayed symmetry and no head.
C) have a water vascular system of radial muscles that pump water through the animal.
D) have dipleurula larva derived from a double-layered balstula.
E) have an external skeleton composed of spicules which give it its 'spiny skin'.

Question 33

A madreporite is

A) the swim bladder of ray-finned fishes.
B) the pectoral appendages of lungfish.
C) a sac at the base of the tube foot of echinoderms which regulate water flow.
D) a porous, sieve-like plate on the body surface of an echinoderm.
E) blocks of muscle on each side of the tunicate body.

Question 34

Mammals

A) have a four-chambered heart and double circulation.
B) are amniotes in which epidermal hair is present at some stage of development.
C) have mammary glands which provide food for the young.
D) are endothermic.
E) All of the answers are correct.

Question 35

Eutherians include a diversity of forms which are believed to have originated from a common ancestor which was

A) a monotreme.
B) a small insectivorous mammal.
C) paleognathae.
D) Homo erectus.
E) an amphibian.

Question 36

Characteristics of gnathostomes include

A) wings and feathers.
B) a mouth like a suction cup.
C) and open vascular system.
D) a backbone composed of vertebrae.
E) a body cavity that develops from the blastocoel.

Question 37

In the embryos of the Pharyngotremata the pharyngeal slits are also known as

A) pharyngeal incisions.
B) pharyngeal cleft.
C) pharyngeal sacs.
D) pharyngeal cleavage.
E) pharyngeal pouches.

Question 38

In pterobranchs, what is the function of the two tentacles on the collar?

A) Gas exchange
B) Waste excretion
C) Thermal regulation
D) Feeding
E) Current sensory

Question 39

A marine biologist is asked to identify an echinoderm and is given a living sample of larvae to use to achieve this goal. Can the scientist identify the class of echinoderm from this sample, and if so what would be the simplest process the scientist could use?

A) No, the echinoderm cannot be identified.
B) Yes, by observing the positions of pharyngeal slits.
C) Yes, the echinoderm can be identified from the larvae by identifying unique molecular markers for each different class and then analysing the DNA of the sample against them.
D) Yes, the echinoderm can be identified from the larvae by performing a micro-dissection performed by an experienced scientist that is intimately familiar with echinoderms.
E) Yes, the echinoderm can be identified from the larvae by simply allowing it to develop projecting arms and observing their arrangement which will be diagnostic of the class.

Question 40

Which of the following is NOT a unique feature of monotremes?

A) A spur on the hind feet that is venomous in males
B) Adults lose their teeth, which are replaced by horny plates
C) A bifurcate penis
D) Females produce an egg with a hard shell
E) Mammary glands lack nipples

Question 41

A zookeeper is responsible for a wallaby enclosure in a zoo. A new, young female has recently joined the enclosure and is soon mated with a virile male. Soon after, blood tests show that the female is pregnant but after a month the female still fails to show any signs of pregnancy. Why could this be so?

A) The female still has a very young offspring in her pouch which is halting the development of the new foetus.
B) Like all marsupials, wallabies have a long gestation period. There will be no indications of pregnancy for several more months.
C) The blood test is faulty.
D) The foetus has a developmental retardation mutation.
E) Young females can exhibit 'phantom' pregnancies that mimic real pregnancy at the biochemical level as a means of placating aggressive males on heat.

Question 42

A monkey hanging from its tail must originate from

A) Sub-saharan Africa.
B) South-East Asia.
C) North Asia.
D) Rift Valley area.
E) tropical America.

Question 43

With the exception of humans, what regions do primates inhabit?

A) Arid
B) Temperate
C) Tundra
D) Intertropical
E) Taiga

Question 44

A natural history museum curator has been tasked with finding fossil specimens of an early human ancestor, specifically Homo ergaster. Where could the curator begin his search to find such a fossil, and how far back in the fossil record would he need to examine?

A) Southern Eurasia, ~175 million years
B) South-East Asia, ~150 million years
C) Europe, ~125 million years
D) Americas, ~100 million years
E) Rift Valley, Africa, ~50 million years

Question 45

From earliest to latest, what is the accepted order of fossil specimens of human ancestors?

A) H. heidelbergensis, H. habilis, H. erectus, H. ergaster
B) H. ergaster, H. habilis, H. heidelbergensis, H. erectus
C) H. habilis, H. heidelbergensis, H. ergaster, H. erectus
D) H. habilis, H. ergaster, H. erectus, H. heidelbergensis
E) All of the answers are incorrect