Explore BrainMass

Explore BrainMass

    characters of echinoderms

    Not what you're looking for? Search our solutions OR ask your own Custom question.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Please help. This is NOT for an assignment. It is to study for an exam. Want to make sure I am on the right track. Thank you.

    (2 marks) 6. List two characters of echinoderms that they do not share with other animal phyla.
    (6 marks) 7. Explain the multiregional hypothesis for the origin of humans, and list two lines of evidence to support it.
    (3 marks) 8. What are the differences between the gastrointestinal systems of a flatworm and an earthworm?
    (6 marks) 9. Using a Canadian example of an endangered or threatened organism, describe the problem the species faces, discuss whether any conservation efforts were made, and describe how successful they were.

    © BrainMass Inc. brainmass.com September 27, 2022, 9:37 am ad1c9bdddf
    https://brainmass.com/biology/animal-biology/characters-echinoderms-616714

    SOLUTION This solution is FREE courtesy of BrainMass!

    Hello,
    Please find below the last installment of the solution to Biology review questions for your ease of reference.

    Thank You for using BrainMass

    Biology Revision questions Solution 3

    1. List two characters of echinoderms that they do not share with other animal phyla.
    1.1. One unique feature is their (usually five-point) radial symmetry comprising several arms (5 or more, mostly grouped 2 left - 1 middle - 2 right), he body actually consists of five equal segments, each containing a duplicate set of various internal organs.
    1.2. The other distinct trait amongst most echinoderms is their remarkable powers of regeneration of tissue, organs, limbs, and of asexual reproduction, and in some cases, complete regeneration from a single limb.(Wikipedia 2016)
    1.3.

    2. Explain the multiregional hypothesis for the origin of humans, and list two lines of evidence to support it.
    2.1.1. The multi-regional hypothesis proposes that our early hominid ancestors, including Homo ergaster and Homo heidelbergensis, migrated out of Africa and thus the evolution of modern humans took place in different parts of the world . (Pettitt, P 2009a: 125-173). This means that the species then eventually experienced variations as it migrated to different regions.
    2.1.2. The two lines of evidence are:
    2.1.2.1. The observation of similarities between the archaic Peking man fossils and modern humans from China in 1940 by Franz Weidenreich Wikipedia 2011 )
    2.1.2.2. A suggestion by Milford Wolpoff and Alan Thorne) that individuality was influenced by gene flow between populations in different regions (Wolpoff, M and Thorne, A 1992)
    3. What are the differences between the gastrointestinal systems of a flatworm and an earthworm?- Platyhelminthes are worms with flat bodies (flatworms), whereas nematodes are worms with cylindrical but not segmented bodies (roundworms). Annelids are cylindrical worms with segmented bodies (they are metameric).

    3.1. Flatworms (Phylum Platyhelminthes) have incomplete digestive systems.
    3.2. That means that their digestive system has only one opening that functions as both mouth and anus.
    3.3. Flatworms possess a branched gastrovascular cavity(http://www.biology-questions-and-answers.com/annelids.html)

    4. Using a Canadian example of an endangered or threatened organism, describe the problem the species faces, discuss whether any conservation efforts were made, and describe how successful they were.
    4.1. the polar bear is an endangered species in Canada
    4.2. Polar bears are found throughout northern Canada from Yukon to Labrador and from northern Ellesmere Island south to James Bay
    4.3. In Canada, polar bears are harvested by Inuit, Indians, and non-native sport-hunters guided by Aboriginal people
    4.4. They are also challenged by availability of food, climatic changes, and increasing development in the north.
    4.5. Conservation efforts made(https://www.registrelep-sararegistry.gc.ca/default.asp?lang=En&n=6DB1BAF3-1&printfullpage=true)
    4.5.1. The Polar Bear was classified by COSEWIC(Committee on the status of Endangered Wildlife in Canada) as vulnerable (A species of special concern because of characteristics that make it particularly sensitive to human activities or natural events)during the last revision of the status of the polar bear in Canada was completed in 1987 .
    4.5.2. The boundaries for the different populations of polar bears in Canada (Fig. 1) have been determined by satellite tracking of female polar bears, mark-recapture studies and return of tags from polar bears of both sexes taken by Inuit hunters (Taylor and Lee 1995; Bethke et al. 1996)
    4.5.3. In Canada, the PBTC conducts an annual review of the status of each population of polar bears and its sustainable harvest, and monitors the annual kill.
    4.6. Whether these efforts are bearing fruit? Read the cited references further

    References:
    1. Wolpoff, M and Thorne, A (1992). 'The Multi-Regional Evolution of Humans' Scientific American, 28-33
    2. Pettitt, P 2009g: 133(Pettitt, P (2009 a-i). The rise of modern humans. In: Scaare, C. The Human Past. 2nd ed. London: Thames and Hudson 124-173)
    3. http://www.cciw.ca/eman/intro.html ; WWF Canada Endangered Spaces Report ; http://parkscanada.pch.gc.ca/np/np_e.htm
    4. Taylor, M.K., and Lee, L.J. 1995. Distibution and abundance of Canadian polar bear populations: A management perspective. Arctic, 48:147-154.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com September 27, 2022, 9:37 am ad1c9bdddf>
    https://brainmass.com/biology/animal-biology/characters-echinoderms-616714

    ADVERTISEMENT