BIOL 225 Lecture Notes - Lecture 1: Symmetry In Biology, Extracellular Fluid, Body Plan
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I need help on this microbiology question:
Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.
Part A - Comparable Earth Environments to Be Found on Another Planet
You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.
Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)
| Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in. |
| Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme. |
| Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes. |
| Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity. |
The Cambrian explosion is a prime example of ________________.
| mass extinction | ||
| evolutionary stasis | ||
| a large meteor impact | ||
| adaptive radiation |
1 points
QUESTION 2
Most animals are viviparous.
True
False
1 points
QUESTION 3
The first phylum with ganglia in their nervous system are the ________________________.
| Mollusca | ||
| Nematoda | ||
| Bivalvia | ||
| Platyhelminthes |
1 points
QUESTION 4
The last common ancestor of all animals was probably a _____________________.
| a unicellular worm | ||
| multicellular algae | ||
| flagellated protist | ||
| multicellular fungus |
1 points
QUESTION 5
You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile by use of many short extensions of the cytoplasm. It has well-developed organelles and two nuclei, one large, one small. The organism is most likely to be a ______________.
| foraminifera | ||
| radiolarian | ||
| ciliate | ||
| flagellate |
1 points
QUESTION 6
Which of the following organisms would you expect to have the largest surface-area-to-volume ratio? Assume that all of the following are the same total length.
| A mollusc | ||
| A nematode | ||
| A platyhelminth | ||
| Not enough information to determine. |
1 points
QUESTION 7
If the animal is a hermaphrodite, it is said to be _______________.
| dioecious | ||
| eutelic | ||
| monoecious | ||
| trioecious |
1 points
QUESTION 8
A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, system of tubes for gas exchange and segmentation. A knowledgeable zoologist should predict that the adults of this species would also feature ____________.
| eight legs | ||
| two pairs of antennae | ||
| a sessile lifecycle | ||
| an open circulatory system |
1 points
QUESTION 9
The Phylum Echinodermata exhibits metamerism.
True
False
1 points
QUESTION 10
The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that _____.
| a larger volume-to-surface area ratio is adaptive in many mammals | ||
| evolution generally progresses toward some goal | ||
| evolution tends toward increased complexity or increased size | ||
| in particular environments, similar adaptations can be beneficial to more than one species |
1 points
QUESTION 11
Suppose you are a researcher fro a pest-control company and you develop a chemical that inhibits the develpment of an embryonic mosquito's endodermal cells. Which of the following would cause the pesticide to work?
| The mosquito would develop a weak exoskeleton, making it easy prey. | ||
| The mosquito's gut would not function properly and it would starve. | ||
| The mosquito would not have a properly functioning muscular system. | ||
| Nothing would happen and your experiment would be a failure. |
1 points
QUESTION 12
Holometabolis refers to complete metamorphosis.
True
False
1 points
QUESTION 13
Which of these conditions are always true of populations evolving due to natural selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
| Condition 1 only | ||
| Condition 2 only | ||
| Conditions 1 and 2 | ||
| Conditions 2 and 3 |
1 points
QUESTION 14
Scientific theories _____. 22.3
| are nearly the same things as hypotheses | ||
| are supported by, and make sense of, many observations | ||
| cannot be tested because the described events occurred only once | ||
| are predictions of future events |
1 points
QUESTION 15
The evolution of animal species and their diversity is a result of the evolution of new and different ways to _______________.
| reproduce | ||
| arrange their cells into tissues | ||
| become symmetrical | ||
| form an embyro and establish a basic body plan |
QUESTION 19
Among all protostomes, which morphological trait is most varied?
| type of symmetry | ||
| type of body cavity | ||
| number of embryonic tissues | ||
| type of development |
1 points
QUESTION 20
Nematodes are acoelomate animals.
True
False
1 points
QUESTION 21
The first genetic material on Earth was probably __________.
| DNA produced by reverse transcription | ||
| DNA molecules whose information was transcribed to RNA | ||
| protobionts | ||
| self-replicating RNA molecules |
1 points
QUESTION 22
Free point. Mark "true"
True
False
1 points
QUESTION 23
Which of the following is a characteristic of a flagellate?
| The use of pseudopods as feeding structures. | ||
| They are often multinucleate. | ||
| They can exchange genetic material with other ciliates by the process of mitosis. | ||
| Most live as solitary autotrophs in fresh water. |
1 points
QUESTION 24
The chelicerates have 2 pair of antennae.
True
False
1 points
QUESTION 25
Nematoes and arthropods both _________________.
| develop an anis from the blastopore formed during gastrulation | ||
| are suspension feeders | ||
| grow by shedding their exoskeleton | ||
| have ciliated larva |
1 points
QUESTION 26
If a lung were to be found in a mollusc, where would it be located?
| incurrent siphon | ||
| mantle cavity | ||
| visceral mass | ||
| excurrent siphon |
1 points
QUESTION 27
True segmentation (metamerism) evolved 3 seperate times.
True
False
1 points
QUESTION 28
The first coelomate animals are the _______________________________.
| Nematoda | ||
| Platyhelminthes | ||
| Mollusca | ||
| Arthropoda |
1 points
QUESTION 29
Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?
| How can amino acids, simple sugars, and nucleotides be synthesized abiotically? | ||
| How did RNA sequences come to carry the code for amino acid sequences? | ||
| How could polymers involving lipids and/or proteins form membranes in aqueous environments? | ||
| How can RNA molecules act as templates for the synthesis of complementary RNA molecules? |
1 points
QUESTION 30
The greatest number of endemic species is expected in environments that are _____.
| easily reached and ecologically diverse | ||
| isolated and show little ecological diversity | ||
| isolated and ecologically diverse | ||
| easily reached and show little ecological diversity |
1 points
QUESTION 31
A population of organisms will not evolve if _____.
| all individual variation is due only to environmental factors | ||
| the environment is changing at a relatively slow rate | ||
| the population size is large | ||
| the population lives in a habitat without competing species present |