
Concept explainers
Test Your Understanding
1. Which of the following is not a shared derived character of echinoderms? (a) water vascular system (b) notochord (c) tube feet (d) pentaradial symmetry in adult (e) endoskeleton of calcium carbonate plates and spines

Introduction: Animal phylogeny is the rapidly changing field for biologists. Even if the members of the animal kingdom are incredibly diverse, there are various animals sharing certain features that differentiate them from other organisms of the kingdom. The most highly derived body plan among all animals of the animal kingdom is echinoderm. Echinoderms are the animals that have no terrestrial or freshwater representatives and these animals belong to marine habitat.
Answer to Problem 1TYU
Correct answer: The presence of notochord is not a shared derived character of echinoderms. Hence, the correct answer is option (b).
Explanation of Solution
Reason for the correct answer:
The shared derived characters of echinoderms are as follows:
- Presence of water vascular system.
- Presence of numerous tiny tube feet.
- Presence of endoskeleton, ciliated epidermis, and thin covering.
- The adults of echinoderms exhibit pentaradial symmetry.
The presence of notochord is one of the characters of chordates. Some of the chordates have notochord during some time of their developmental cycle, whereas some chordates have notochord during their whole life time like vertebrates. It is not the shared derived character of echinoderms.
Option (b) is given as “notochord”.
The presence of notochord is not a shared derived character of echinoderms. Hence, the correct answer is option (b).
Reasons for the incorrect answers:
Option (a) is given as “water vascular system”.
The unique structural derived character of echinoderms is the presence of a network of fluid-filled canals and chambers called water vascular system. Hence, option (a) is incorrect.
Option (c) is given as “tube feet”.
The presence of numerous tiny tube feet is one the structural unique character of echinoderms. Hence, option (c) is incorrect.
Option (d) is given as “pentaradial symmetry in adult”.
The echinoderm adult exhibits pentaradial symmetry and the larval form exhibits bilateral symmetry. Hence, option (d) is incorrect.
Option (e) is given as “endoskeleton of calcium carbonate plates and spines”.
The presence of endoskeleton, ciliated epidermis, and thin covering is the unique feature of echinoderm. The endoskeleton of echinoderms consists of calcium carbonate (CaCO3) spines and plates. Hence, option (e) is incorrect.
Hence, options (a), (c), (d), and (e) are incorrect.
The presence of notochord is not a shared derived character of echinoderms.
Want to see more full solutions like this?
Chapter 32 Solutions
Biology (MindTap Course List)
- Using quail and chicken embryos, what kind of experiment would you conduct to test if rib forming somites have their axial identity specified before segmentation? How do we know this phenotype is due to axial identity being specified before segmentation and not due to our experimental method?arrow_forward8. Aerobic respiration of a 5 mM solution of tripeptide that is composed of the following three amino acids; alanine, leucine and isoleucine. Alanine breaks down to pyruvate, leucine breaks down to Acetyl-CoA and isoleucine breaks down to succinyl-CoA. Alanine NADH FADH2 OP ATP SLP ATP Total ATP Leucine Isoleucine Totals Show your work using dimensional analysis here: 4arrow_forward9. Aerobic respiration of one lipid molecule. The lipid is composed of one glycerol molecule connected to two fatty acid tails. One fatty acid is 12 carbons long and the other fatty acid is 18 carbons long in the figure below. Use the information below to determine how much ATP will be produced from the glycerol part of the lipid. Then, in part B, determine how much ATP is produced from the 2 fatty acids of the lipid. Finally put the NADH and ATP yields together from the glycerol and fatty acids (part A and B) to determine your total number of ATP produced per lipid. Assume no other carbon source is available. fatty acids glycerol 18 carbons 12 carbons 0=arrow_forward
- If using animals in medical experiments could save human lives, is it ethical to do so? In your answer, apply at least one ethical theory in support of your position.arrow_forwardYou aim to test the hypothesis that the Tbx4 and Tbx5 genes inhibit each other's expression during limb development. With access to chicken embryos and viruses capable of overexpressing Tbx4 and Tbx5, describe an experiment to investigate whether these genes suppress each other's expression in the limb buds. What results would you expect if they do repress each other? What results would you expect if they do not repress each other?arrow_forwardYou decide to delete Fgf4 and Fgf8 specifically in the limb bud. Explain why you would not knock out these genes in the entire embryo instead.arrow_forward
- You implant an FGF10-coated bead into the anterior flank of a chicken embryo, directly below the level of the wing bud. What is the phenotype of the resulting ectopic limb? Briefly describe the expected expression domains of 1) Shh, 2) Tbx4, and 3) Tbx5 in the resulting ectopic limb bud.arrow_forwardDesign a grafting experiment to determine if limb mesoderm determines forelimb / hindlimb identity. Include the experiment, a control, and an interpretation in your answer.arrow_forwardThe Snapdragon is a popular garden flower that comes in a variety of colours, including red, yellow, and orange. The genotypes and associated phenotypes for some of these flowers are as follows: aabb: yellow AABB, AABb, AaBb, and AaBB: red AAbb and Aabb: orange aaBB: yellow aaBb: ? Based on this information, what would the phenotype of a Snapdragon with the genotype aaBb be and why? Question 21 options: orange because A is epistatic to B yellow because A is epistatic to B red because B is epistatic to A orange because B is epistatic to A red because A is epistatic to B yellow because B is epistatic to Aarrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
- Biology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781337408332Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781305073951Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage Learning





