Bio-106-Ex1
The temperature at which an alligator's egg is incubated will determine the sex of the offspring. The dependent and the independent variables in this experiment are ________.
sex of the baby alligator and temperature respectively
An atom has four electrons in its valence shell. What types of covalent bonds is it capable of forming?
single, double, or triple
An ion with six protons, seven neutrons, and a charge of 2+ has an atomic number of ________.
six
To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first?
specific heat
What is the hydrogen ion (H+) concentration of a solution of pH 8?
10-8M
A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7?
100 times
Refer to the following figure to answer the questions below. How many electrons are present in a Phosphorus 3+ atom?
12
What is the maximum number of covalent bonds that an oxygen atom with atomic number 8 can make with hydrogen?
2
How many electrons are involved in a triple covalent bond?
6
Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?
Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.
if the pH of a solution is decreased from 9 to 8, it means that the concentration of _____.
H+ has increased tenfold (10X) compared to what it was at pH 9
Which of the following are compounds?
H2O and CH4, but not O2
Which of the following are qualities of any good scientific hypothesis? I. It is testable.•II. It is falsifiable.•III. It produces quantitative data.•IV. It produces results that can be replicated.
I and II
If an atom has a charge of +1, which of the following must be true?
It has one more proton than it does electrons.
A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?
It is a strong acid that dissociates completely in water.
Which of the following best describes a model organism?
It is well studied, it is easy to grow, and results are widely applicable.
In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there were a total of eight treatment groups (4 environments × 2 diets).Recall that in the experiment, caterpillars born in the spring looked like flowers, and caterpillars born in the summer looked like twigs. What is the most likely selective advantage for this difference in body shape?
Looking like their food source lets the caterpillars blend into their surroundings, reducing predation.
Use the following information when answering the following question.In 1668, Francesco Redi performed a series of experiments on spontaneous generation. He began by putting similar pieces of meat into eight identical jars. Four jars were left open to the air, and four were sealed. He then did the same experiment with one variation: Instead of sealing four of the jars completely, he covered them with gauze (the gauze excluded the flies while allowing the meat to be exposed to air). In both experiments, he monitored the jars and recorded whether or not maggots (young flies) appeared in the meat.What hypothesis was being tested in the initial experiment with open versus sealed jars?
Maggots do not arise spontaneously, but from eggs laid by adult flies.
Agrobacteriuminfects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to these bacteria to become infected. Which of the following experiments will provide the best data to address that question?
Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time.
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?
MgCl2
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. Which of the following can be true?
Molybdenum atoms can have between 50 and 58 neutrons.
Following a scientific method, which of the following is the correct order of steps?
Observation → Hypothesis → Experiment → Analysis → Conclusion → Communicate results
In presenting data that result from an experiment, a group of students show that most of their measurements fall on a straight diagonal line on their graph. However, two of their data points are "outliers" and fall far to one side of the expected relationship. What should they do?
Show all results obtained and then try to explore the reason(s) for these outliers
Which of the following is the best description of a control for an experiment?
The control group is matched with the experimental group except for one experimental variable.
Which of the following is an example of qualitative data?
The fish swam in a zigzag motion.
Agrobacterium infects plants and causes them to form tumors. You determine that tumor formation requires a large amount of the plant's energy for tissue formation. How might this change the number of offspring a plant produces, and what is the most likely explanation for this change?
The number of offspring should decrease because the plant will divert energy from reproduction to tumor formation.
The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why?
The ocean near Portland moderates the temperature.
How does a scientific theory differ from a scientific hypothesis?
Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues.
The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both ___adhesion,____ to the conducting walls and wood fibers of the plant and ___cohesion,____ of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a ___ nonpolar solution____ with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment?
Transpiration rates will fall to zero as nonpolar compounds do not have the properties necessary for adhesion and cohesion.
How many electron pairs are shared between carbon atoms in a molecule that has the formula C2H4?
Two
Can the atomic mass of an element vary?
Yes. Adding or losing neutrons will change the atomic mass without forming a different element.
If the pH of blood increases, one would expect _____.
a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-
In the process of science, which of these is tested?
a hypothesis
Atoms have no electric charge because they have ________.
an equal number of protons and electrons
About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?
carbon, hydrogen, nitrogen, oxygen
Which bond or interaction would be difficult to disrupt when compounds are put into water?
covalent bonds between carbon atoms
Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should _____.
determine if hair length is heritable
A strong acid like HCl _____.
dissociates completely in an aqueous solution
strong acid like HCl _____.
dissociates completely in an aqueous solution
A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge.
electron; neutron
A scientist, who wants to study the effects of nitrogen on wheat plants, sets up an experiment with 4 groups of wheat plants: group A gets 20 pounds per acre, group B gets 40 pounds per acre, group C gets 60 pounds per acre, and group D gets 0 pounds per acre. Which of the following is the control group?
group D
Which type of bond must be broken for water to vaporize?
hydrogen bonds
The best experimental design _____.
includes a large sample size and a control, and alters only one condition between the controls and the experimental condition
The best experimental design ________.
includes a large sample size and a control, and alters only one condition between the controls and the experimental condition
A controlled experiment _____.
includes at least two groups, one of which does not receive the experimental treatment
In a chemical reaction, the element 13Al will most preferably ________.
lose three electrons and become positively charged
Bonds between two atoms that are equally electronegative are ________.
nonpolar covalent bonds
Hydrophobic substances such as vegetable oil are _____.
nonpolar substances that repel water molecules
Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H2S will _____.
not form hydrogen bonds with each other
Carbon-14 has the same ________.
number of protons but more neutrons than carbon-12
What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-12 M?
pH 2
What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-12M?
pH 2
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____.
polar covalent bonds
A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead. If so, then jump-starting the car from a good battery will solve the problem. In doing so, you are
stating a hypothesis and using that hypothesis to make a testable prediction
salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a ________.
surface of hydrocarbons
When are atoms most stable?
when all of the electron orbitals in the valence shell are filled