test your knowledge - exam 2
Place the following evolutionary milestones in order from earliest (1) to the most recent (7). _____ The First multicellular eukaryotes _____ The First prokaryotes _____ The Permian extinction _____ The Cambrian explosion _____ The first animals _____ The extinction of dinosaurs _____ An increase in oxygen in the atomsphere
1 - the first prokaryotes 2 - an increase in oxygen in the atmosphere 3 - the first multicellular 4 - the cambrian explosion 5 - the first animals 6 - the permian extinction 7 - the extinction of dinosaurs
Put the following terms in order from most inclusive (1) to least inclusive (5): _______ domain _______ species _______ kingdom _______ genus _______ phylum
1- domain 2- kingdom 3- phylum 4- genus 5- species
The term prokaryotic refers to:
A type of cell structure
Which of the following is NOT a domain of life? A. animalia B. Eukarya C. Bacteria D. Archaea E. Plantae F. Neither a nor e is a domain of life
Animalia and plantar are not domains of life
Organisms are placed into one or another of the three domains of life on the basis of:
Evolutionary history as assessed by genetic relatedness
The absence of membrane-bound organelles in a cell tells you that the cell must be:
From a member of the domain Bacteria or From a member of the domain Archaea
List the features that make Lost City a particularly harsh environment For each feautre, give a brief explanation of why that environment is inhospitable for many organisms.
High temperatures: most organisms are not adapted to high temperatures, and if they encounter temperatures higher than their optimum temperatures, their proteins will denature and their membranes will destabilize. High pressure: most organisms do not have adaptations that allow them to survive at high pressure and would be crushed by the pressure at Lost City High pH: the high pH at Lost City is outside the pH optimum of most organisms, and would lead to their death.
If you were a prokaryotic organism and wanted to be successful at Lost City, what energy source must you be able to use?
Hydrogen gas
If two organisms strongly resemble each other in their physical traits, can you necessarily conclude that they are closely related? Explain your answer.
No. While they may be closely related, they may also represent convergent evolution, in which unrelated groups of organisms share common characteristics because of independent natural selection in similar environments.
If you are unable to culture archaea from an environmental sample, is it safe to conclude that there are no archaea present? Why or why not?
No. You cannot conclude that there are no archaea present in that environment or sample. Many archaea are very difficult to grow (that is, culture) in the lab. This is likely because we don't understand enough about their growth requirements to be able to provide the appropriate conditions to culture them successfully in the lab. They may be present in the environmental sample, and we may just be unable to culture them.
If you were looking for a bacterium, where would you expect to find one?
On your skin, in soil, in the ocean, associated with plants
If phosphorus is important for bones and teeth, why do plants need phosphorus?
Plants absorb this and use to synthesize organic compounds
What is the role of endosperm in a seed?
The endosperm provides nutrients to the developing embryo.
Describe the major difference(s) between prokaryotic and and eukaryotic organisms.
The key difference is that prokaryotic cells do not contain membrane-enclosed organelles, particularly a nucleus. Eukaryotic cells are defined by the presence of membrane-enclosed organelles, in particular the nucleus.
What do all members of the informal group known as protists have in common?
They are all eukaryotic.
What do mosquitos, snails, and earthworms have in common?
They are all invertebrates
What do uranium-238, carbon-14, and potassium-40 have in common?
They are all radioactive isotopes that decay into other elements at constant rates.
To date, what you suspect to be the very earliest life on Earth, what isotope would you use: uranium-238, carbon-14, or potassium-40? Explain your answer.
You would use uranium-238, which has the longest half-life of the three (4.5 billion years). Isotopes with shorter half-lives may no longer be present in very ancient samples, having completely decayed.
A phylogenetic tree represents
a grouping of organisms on the basis of their evolutionary history
What are the defining features of eukaryotes, members of the domain Eukarya?
an organism whosecells contain a nucleus, numerous membrane-bound organelles, and an extensive cytoskeleton. May beunicellular or multicellular.
Which of the following is not a reservoir of phosphorus?
atmospheric gasses
Which form of nitrogen is abundant in the atmosphere?
dinitrogen
Which of the following defense/predator avoidance features or strategies can be found in arthropods?
exoskeleton
Which group of plants was the first to live on land? Why do we find these plants only in particular environments (after all, if they were the first, shouldn't they have spread everywhere by now)?
moss, they are non vascular and do not have deep roots
Which form of nitrogen can be easily taken up and used by plants?
nitrate
Which of the following is not a feature of all animals?
not all animals have tissues, organs, and organ systems.
When examining archaea, which of the following is not a trait that you could expect to find?
nucleus
The ________ is the female gamete. In angiosperms, it is found in an ________, which in turn is found in the _________.
ovule, ovary, egg
Which of the following is not a characteristic found in at least some organisms in the domain Eukarya?
photosynthesis
A sand dollar gets its name from its body shape—it resembles a large coin. What type of body symmetry does a sand dollar have?
radial
A major difference between a fern and a moss is
the presence of a vascular system, ferns are vascular, but moss is not
Which of the following is consistent with organic farming practices?
using Bt toxin proteins as an insecticide