BSC 2011L – Principles of Biology 2 Lab
Lab Topic 19 – Animal Diversity II:
Nematoda, Arthropoda, Echinodermata, and Chordata
Lab Topic 19: Animal Diversity II
• This lab topic is a continuation of observations of
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organisms in the animal kingdom (clade Metazoa)
as discussed in lab topic 18.
In this lab we will look at examples of nematodes
and arthropods (clade Ecdysozoa) and two
deuterostome phyla (Echinodermata and Chordata)
1. What clues do similarities and differences among
organisms provide about phylogenetic
relationships?
2. How is body form related to function?
3. How is body form related to environment and
lifestyle?
4. What characteristics can be the criteria for major
branching points in producing a phylogenetic tree?
Exercise 19.1 – Nematoda
• Roundworms (Ascaris)
• Materials
• Introduction
• Procedure
• Results
– 1. Sketch the cross-section of a female Ascaris
– 2. List some features of Ascaris that are possible
adaptations to parasitic life.
– 3. Complete Table 19.1 for roundworm
characteristics
• Discussion
– 1. Discuss the significance of the an animal’s
having two separate openings to the digestive
tract.
– 2. What are the advantages of a body cavity being
present in an animal?
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Exercise 19.2 – Phylum Arthropoda
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Lab Study A. Crayfish (Cambarus)
Materials
Introduction
Procedure
Results
– 1. Complete Tables 19.1 and 19.2 for crayfish
characteristics
• Discussion
– How does the pattern of segmentation differ
in the crayfish and the earthworm studied in
lab topic 18?
Exercise 19.2 – Phylum Arthropoda
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Lab Study B. Grasshoppers (Romalea)
Materials
Introduction
Procedure
Results
– 1. Complete Tables 19.1 and 19.2 for
grasshopper characteristics
• Discussion
– How does the pattern of segmentation differ
in the crayfish and the earthworm studied in
lab topic 18?
Anatomy of a Grasshopper
Anatomy of a grasshopper, an insect
Abdomen Thorax Head
Compound eye
Antennae
Heart
Cerebral ganglion
Dorsal
artery Crop
Anus
Vagina
Malpighian
tubules
Ovary
Tracheal tubes
Mouthparts
Nerve cords
Exercise 19.3 – Phylum Echinodermata
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Sea Star
Materials
Introduction
Procedure
Results
– 1. Complete Table 19.1 for the sea star
characteristics and complete Table 19.2 in the
Applying Your Knowledge section
• Discussion
– Answer the four discussion questions at the
end of this exercise
Anus
Stomach
Spine
Gills
Central disk
Digestive glands
Madreporite
Radial
nerve
Ring
canal
Gonads
Ampulla
Podium
Radial canal
Tube
feet
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(a) A sea star (class Asteroidea)
(b) A brittle star (class Ophiuroidea)
(c) A sea urchin (class Echinoidea)
(d) A feather star (class Crinoidea)
(e) A sea cucumber (class Holothuroidea)
(f) A sea daisy (class Concentricycloidea)
Exercise 19.4 – Phylum Chordata
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Lab Study A. Lancelets (Branchiostoma)
Materials
Introduction
Procedure
Results
– 1. Complete the diagram of a lancelet cross
section in Figure 19.10. Label all of the structures
listed in step 4 of the Procedure section.
– 2. Complete Table 19.1 and Table 19.2 in the
Applying Your Knowledge section
• Discussion
– Describe the uniquely chordate features that you
have detected in the lancelet that were not
present in the animals previously studied.
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Chordate characteristics
Dorsal,
hollow
nerve cord
Muscle
segments
Notochord
Mouth
Anus
Muscular,
post-anal tail
Pharyngeal
slits or clefts
The lancelet, a cephalochordate
Cirri
2 cm
Mouth
Pharyngeal slits
Atrium
Notochord
Digestive tract
Atriopore
Dorsal, hollow
nerve cord
Segmental
muscles
Anus
Tail
Cross-section of Branchiostoma
Exercise 19.4 – Phylum Chordata
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Lab Study B. Fetal pigs (Sus scrofa)
Materials
Introduction
Procedure
Results
– Complete Table 19.1 for the pig characteristics.
– Use this information to complete Table 19.2 and
answer questions in the Applying Your
Knowledge section that follows.
• Questions for Review
– Complete questions 1-2
• Applying Your Knowledge
– Complete questions 1-8