CHAPTER 2 Test Your Knowledge
Driving Question 1
How is matter organized into molecules of living organisms?
By answering the questions below and studying Infographics 2.3, 2.4, and 2.8 and Up Close: Molecules of Life, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
How is matter organized into molecules of living organisms?
By answering the questions below and studying Infographics 2.3, 2.4, and 2.8 and Up Close: Molecules of Life, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
What subatomic particles are located in the nucleus of an atom?
a. protons
b. neutrons
c. electrons
d. protons, neutrons, and electrons
e. protons and neutrons
When an atom loses an electron, what happens?
a. It becomes positively charged.
b. It becomes negatively charged.
c. It becomes neutral.
d. Nothing happens.
e. Atoms cannot lose an electron because atoms have a defined number of electrons.
Glucose (a monosaccharide) has the molecular formula C6H12O6. How many carbon atoms are in each glucose molecule?
USE IT
Consider the types of lipid.
a. How does a sterol, such as cholesterol, differ from a triglyceride?
b. Structurally, what do triglycerides and phospholipids have in common?
A cell is unable to take up or make sugars. Which molecule(s) will it be unable to make?
a. carbohydrates
b. proteins
c. lipids
d. nucleic acids
e. all of the above
f. a and d
Driving Question 2
What is the definition of life, and how could Martian life be recognized?
By answering the questions below and studying Infographics 2.1 and 2.10, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Which of the following is not a generally recognized characteristic of most (if not all) living organisms?
a. the ability to reproduce
b. the ability to maintain homeostasis
c. the ability to obtain energy directly from sunlight
d. the ability to sense and respond to the environment
e. the ability to grow
What is homeostasis? Why it is important to living organisms?
What does it mean to say a macromolecule is a polymer? Give an example.
A collection of amino acids could be used to build a
a. protein.
b. complex carbohydrate.
c. triglyceride.
d. nucleic acid.
e. cell.
USE IT
How would you assess whether or not a possibly living organism from another planet were truly alive?
Which of the characteristics of living organisms (if any) allow you to distinguish between living and formerly living (that is, dead) organisms? Explain your answer.
If, in a mound of dirt, you had evidence that carbon dioxide was being consumed and converted to glucose, what could you conclude about the presence of a living organism? Explain your answer.
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Driving Question 3
What is the basic structural unit of life?
By answering the questions below and studying Infographics 2.5 and 2.10, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
The basic building blocks of life are
a. DNA molecules.
b. cells.
c. proteins.
d. phospholipids.
e. inorganic molecules.
The cell membrane is made of
a. water.
b. proteins.
c. phospholipids.
d. nucelotides.
e. b and c.
USE IT
What are the arguments for and against considering viruses living organisms?
Why do phospholipids form a bilayer in water-based solutions?
Driving Question 4
Why is water so important for life and living organisms?
By answering the questions below and studying Infographics 2.5, 2.6, 2.7, 28, and 2.9, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Is olive oil hydrophobic or hydrophilic? What about salt? Explain your answer.
The “stickiness” of water results from the ______________bonding of water molecules.
a. hydrogen
b. ionic
c. covalent
d. acidic
e. hydrophobic
Coffee or tea with sugar dissolved in it is an example of a water-based solution.
a. What is the solvent in such a beverage?
b. What is the solute in such a beverage?
c. Given that the sugar has dissolved in the beverage, are sugar molecules hydrophobic or hydrophilic?
As an acidic compound dissolves in water, the pH of the water
a. increases.
b. remains neutral.
c. decreases.
d. doesn’t change.
e. becomes basic.
The bond between the oxygen atom and a hydrogen atom in a water molecule is a(n) ___________bond.
a. covalent
b. hydrogen
c. ionic
d. hydrophobic
e. noncovalent
How do ionic bonds compare to hydrogen bonds? What are the similarities and differences?
USE IT
Why do olive oil and vinegar (a water-based solution) tend to separate in salad dressing? Will added salt dissolve in the oil or in the vinegar? Explain your answer.
Which of the following are most likely to dissolve in olive oil?
a. a polar molecule
b. a nonpolar molecule
c. a hydrophilic molecule
d. a and c
e. b and c
INTERPRETING DATA
Look at Infographic 2.9 and classify each of the following as an acid or a base and state the hydrogen ion concentration relative to a solution with a neutral pH: drain cleaner; coffee; soda.
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MINI CASE
One approach to finding out if there is life on Mars is to bring Martian dirt samples to Earth for analysis. What are possible considerations for science and society if a Martian life form is released on Earth? Given that Curiosity has landed on Mars, what are the possible consequences if an Earth life form is released on Mars? What steps can mission control take to minimize these risks?
BRING IT HOME
Your tax dollars are being invested in projects such as the Curiosity rover project. Investigate the NASA website to learn more about NASA’s rationalization for the investment in this mission. Now draft a letter to your congressional representative that expresses your opinion about this expenditure of taxpayer dollars. If you agree, state specific reasons why you think this a good investment of your money. If you disagree, state your reasons, and describe at least two other programs that you would prefer to see funded.