Question 1

Which of the following factors, when used to label the horizontal axis of the accompanying graph, would account most directly for the shape of the plot?

Accepted Answer

A)  spongin concentration (gm/unit volume) 
B)  rate of cribrostatin synthesis (molecules/unit time) 
C)  number of pores per sponge 
D)  number of spicules per sponge 
E)  number of choanocytes per sponge 
A)  spongin concentration (gm/unit volume) 
B)  rate of cribrostatin synthesis (molecules/unit time) 
C)  number of pores per sponge 
D)  number of spicules per sponge 
E)  number of choanocytes per sponge

Question 2

Most cnidarians are known to produce toxins. In fact, it has been claimed that one particular species produces the most deadly of all toxins on the planet. What feature of this group most likely evolved simultaneously with the evolution of these toxins?

Accepted Answer

A)  the medusa body form 
B)  asexual reproduction 
C)  a slow-moving or sessile lifestyle in the adult 
D)  diploblastic design 
E)  bilateral symmetry in the mobile larval forms 
A)  the medusa body form 
B)  asexual reproduction 
C)  a slow-moving or sessile lifestyle in the adult 
D)  diploblastic design 
E)  bilateral symmetry in the mobile larval forms

Question 3

Use the following information to answer the question below.
Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and consist of a total of about 2000 cells, which are diploid (2n = 12). There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. They move using cilia, and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage.
Tp's body symmetry seems to be most like that of ________.

Accepted Answer

A)  most sponges 
B)  cnidarians 
C)  worms 
D)  tetrapods 
A)  most sponges 
B)  cnidarians 
C)  worms 
D)  tetrapods

Question 4

The digestive system of most animals is lined with cells through which nutrients are absorbed. What is the embryonic origin of these cells?

Accepted Answer

A)  endoderm 
B)  ectoderm 
C)  mesoderm 
A)  endoderm 
B)  ectoderm 
C)  mesoderm

Question 5

The last common ancestor of all animals was probably a ________.

Accepted Answer

A)  unicellular chytrid 
B)  unicellular yeast 
C)  multicellular algae 
D)  multicellular fungus 
E)  flagellated protist 
A)  unicellular chytrid 
B)  unicellular yeast 
C)  multicellular algae 
D)  multicellular fungus 
E)  flagellated protist

Question 6

The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following is most directly involved in the evolution of these variations in metamorphosis?

Accepted Answer

A)  artificial selection of sexually immature forms of insects 
B)  changes in the homeobox genes governing early development 
C)  the evolution of meiosis 
D)  the development of an oxidizing atmosphere on Earth 
E)  the origin of a brain 
A)  artificial selection of sexually immature forms of insects 
B)  changes in the homeobox genes governing early development 
C)  the evolution of meiosis 
D)  the development of an oxidizing atmosphere on Earth 
E)  the origin of a brain

Question 7

-In the experiment outlined in the accompanying table, what would you expect to happen if researchers supplied an enzyme that blocked the expression of the Dll gene?

Accepted Answer

A)  The embryo would have appendages in abnormal locations. 
B)  The origins of the embryo's appendages would fluoresce. 
C)  The developing embryo would have no appendages. 
D)  The embryo's appendages would be shorter than usual. 
A)  The embryo would have appendages in abnormal locations. 
B)  The origins of the embryo's appendages would fluoresce. 
C)  The developing embryo would have no appendages. 
D)  The embryo's appendages would be shorter than usual.

Question 8

If you think of the earthworm body plan as a drinking straw within a pipe, where would you expect to find most of the tissues that developed from endoderm?

Accepted Answer

A)  lining the straw 
B)  lining the space between the pipe and the straw 
C)  forming the outside of the pipe 
D)  forming the outside of the straw 
A)  lining the straw 
B)  lining the space between the pipe and the straw 
C)  forming the outside of the pipe 
D)  forming the outside of the straw

Exam 30: An Introduction to Animals

Which of the following factors, when used to label the horizontal axis of the accompanying graph, would account most directly for the shape of the plot?

Most cnidarians are known to produce toxins. In fact, it has been claimed that one particular species produces the most deadly of all toxins on the planet. What feature of this group most likely evolved simultaneously with the evolution of these toxins?

The digestive system of most animals is lined with cells through which nutrients are absorbed. What is the embryonic origin of these cells?

The last common ancestor of all animals was probably a ________.

-In the experiment outlined in the accompanying table, what would you expect to happen if researchers supplied an enzyme that blocked the expression of the Dll gene?

If you think of the earthworm body plan as a drinking straw within a pipe, where would you expect to find most of the tissues that developed from endoderm?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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