18.1 Finding Order in Diversity
|1. What is the problem with using common names to describe and categories organisms?||There can be many of them, and they might refer to different species.|
|2. What is binomial nomenclature? Which two parts of an organismâ€™s classification are used? Google your favorite plant or animal and report its binomial (scientific) name.||A two word naming system where each species has its own specific name.
|3. The scientific name for some species of llama is â€œLlama glamaâ€. Did that fun fact make you smile?||Oui.|
|4. Put the following terms in the correct order from most general to most specific (Containing the largest number of organisms to containing the smallest number of organisms):
order, phylum, genus, kingdom, species, family, class
|Kingdom, phylum, class, order, family, genus, species. Â
(King phillip came over from germany saturday.)
|5. Linnaeusâ€™s strategy of classification focused mostly on physical similarities and differences. Is there a problem with that? What characteristics might scientists use today to classify organisms more accurately?||There is a problem because scientists wonâ€™t know which traits to categorize by. Â Today scientists might use DNA testing for more accurate results.|
18.2 Modern Evolutionary Classification
|1. What is phylogeny?||The evolutionary history of lineages.|
|2. The terms â€œcladeâ€ and â€œmonophyletic groupâ€ can both be used for the same thing. What specific groups of organisms are these terms referring to?||Ones that have a common ancestor.|
|3. i. What is the function of a cladogram?
ii.How is speciation represented in a cladogram?
|4. According to the cladogram on page 517, which species is more closely related to crocodiles: birds, or lizards?||birds|
|5i. Â What is a derived character?
ii. Give an example of a derived character
iii. Give an example of a trait that would NOT be considered a derived character, and explain why
|6. Look at the cladogram on page 519.
Briefly explain what information a cladogram can tell you, and at least one piece of information that a cladogram cannot tell you.
|It can tell us what points species evolved from, but it can not tell us why they evolved the way they did.|
|7. Our classification system still has its weaknesses, but sometimes we must classify organisms in ways that do not align with cladistics.
Explain why the class reptilia is not considered a clade.
|Reptilia is not a clade because there is another class with birds in it. Â Reptilia would only be a clade if birds were included in the class.|
|8. A scientist may use a cladogram as a tool to hypothesize evolutionary relationships. How might a scientist test to see if his or her cladogram is correct? (Hint: page 521)||A scientist would take DNA samples of all the species on the cladogram and compare the changes to see if they were correct.|
18.3 Building the Tree of Life
|1. The late 1800s was when scientists began to realize that there is more to life than plants and animals, and another key kingdom – the protists – was created. What major piece of technology to you think led to this new way of looking at life?||Modern microscopes?|
|2. Explain the change from the single kingdom â€œMoneraâ€ to â€œEubacteriaâ€ and â€œArchaebacteriaâ€.||Scientists looked at the genetics and realized that there were some differences|
|3. We (lovingly) refer to the protists as the random group of organisms that donâ€™t really fit anywhere else. Use the term â€œmonophyletic groupsâ€ to explain this in a more scientifically accurate way.
Hint: Donâ€™t know what a monophyletic group is? Â Revisit section 18.2
|Protists are their oun monophyletic group because they have a different common ancestor than the other kingdoms.|
|4. Briefly describe the main characteristics of the three domains.||Bacteria; unicellular and prokaryotic, have peptidoglycan in their cell walls.
Archaebacteria: unicellular and prokaryotic. Â Â Lack peptidoglycan and have unusual lipids.
Eukarya; Â Have a nucleus. Â
|5. It seems strange that the Bacteria and Archaea domains each only have one kingdom. Why canâ€™t scientists put bacteria and archaea into one domain, branching away from eukarya at one point and then separating from each other later?
In other words, why would this be wrong:
Hint: Think about how we read cladograms
|They evolved to have a nucleus, that would imply that the bacterias evolved to not have one. Â
THey cannot be their own kingdom because there are too many differences between them.
|6. Name and briefly describe the four kingdoms within the domain Eukarya.||Fungi Â heterotrophs with cell walls containing chitin. Â Feed on dead matter by secreting enzymes. Mostly multicellular.
Plantae Â Autotrophs with cell walls containing cellulose. Â Nonmotile and use photosynthesis to create food.
Protista Â Mostly unicellular, some are synesthetic while others are heterotrophic. Â Many look like other kingdoms.
Animalia Â Multicellular and heterotrophs. Â No cell walls and can move around. Â