Instructions: Please choose the best answer to each question, but do not guess. Each correct answer is worth 5 points. 1.25 points will be deducted for each wrong answer. You have 40 minutes to complete the test. Note: All necessary formulas are included with the individual questions.
 

    1. The Geiger-Marsden experiment showed that:

1. The "plum pudding" model of the atom was correct.
2. The diameter of the atom was about 10^-10 m.
3. The atom was composed of electrons, neutrons and protons.
4. The atom included a very small, massive nucleus.
2. Balmer’s formula, , gives the frequencies of the spectral lines emitted by the hydrogen atom. This implies that the electron in the hydrogen atom:
 
1. Must have discrete energy levels.
2. Must be in a circular orbit.
3. Must always be radiating electromagnetic energy.
4. Must be inside the nucleus of the atom.


3.Which of the following statements about the photoelectric effect is not correct?
 

1. The photoelectric effect is consistent with the idea that a "bundle" of light with frequency n has energy hn
2. The energy of electrons emitted from a metal surface by a beam of light depends on the intensity of the light.
3. The energy of electrons emitted from a metal surface by a beam of light depends on the frequency of the light.
4. The energy of the light "bundles" or photons must be greater than the work function W of the surface for them to cause electrons to be emitted from the metal surface.


4. Which of the following statements about the Bohr model of the hydrogen atom is not correct?
 

1. The size of the atom is related to .
2. The electron circles the nucleus in a stable orbit with a discrete energy.
3. Photons ("bundles" of light) with any frequency can be emitted from the hydrogen atom according to the Bohr model.
4. The frequency of photons emitted from the hydrogen atom is related to the differences in energy between levels.


5. According to the Bohr model, the energy of the n’th state of the hydrogen atom is given by . How much energy is required to raise an electron in hydrogen from the second level to the third level?
 

1. 13.6 eV
2. 1.9 eV ...(-13.6/9 -(-13.6/4))= -1.5 + 3/4 eV
3. 1.5 eV
4. 3.4 eV
5. –3.4 eV


6. According to Darwin, evolution is caused by "natural selection". Natural selection requires:
 

1. Relatively little variation in the characteristics of a species.
2. Random genetic mutations.
3. The inheritance of species characteristics from one generation to the next.
4. Wide variations in characteristics among members of a species, and the inheritance of characteristics from one generation to the next. (We had this question on a previous quiz!)


7. Which of the following statements about human immunodeficiency viruses is not true.
 

1. These viruses transmit their genetic information through RNA rather than DNA.
2. HIV-1 and HIV-2 are different varieties of the same virus. (They are separate species.)
3. HIV-1 and HIV-2 both evolved from a common ancestor.
4. HIV-1 and HIV-2 can be present in the same person.


8. By examining the mitochondrial DNA of dogs we can determine that:
 

1. They were first domesticated in two different places.
2. They evolved from coyotes
3. They evolved from foxes.
4. The different breeds of dogs can be traced to a variety of ancestors.


9. Farmers have emulated the processes of evolution to produce crops with outstanding commercial qualities. However, this has led to a reduction in the variety of many food crops. What is the greatest drawback to this practice?
 

1. Loss of nutritional value.
2. Lack of taste.
3. Crops may not adapt well to various soil conditions.
4. This increases the likelihood of crop failure from disease. (A single pest could wipe out an entire crop.)


10. Which of the following statements best characterizes a unique species of animal?
 

1. There is essentially no difference in the DNA of all the members of a unique species.
2. They all look alike.
3. They do not mate with any other species.
4. The members of a unique species can mate with each other to produce fertile offspring.


11. Which of the following statements best describes the Malthusian’ theory of population growth.
 

1. The human population grows approximately linearly.
2. The human population grows approximately exponentially, while food supplies grow linearly.
3. Famine and disease limit the growth of human population.
4. The human populations doubles every 40 years.


12. The struggle for existence can turn on factors that may seem insignificant at first glance. For example, some parts of the Pacific Ocean are almost devoid of life because the water has too little:
 

1. Phosphorous
2. Nitrogen
3. Sunlight
4. Iron


13. What is the length of the typical "food chain" in nature?
 

1. Four or five species.
2. One or two species.
3. A dozen or more species.
4. A hundred or more species.


14. Natural selection works to ensure the survival of:
 

1. All members of a species.
2. Only the biggest and strongest members of a species.
3. Those members of a species best adapted to their environment.
4. The fittest.


15. The male peacock’s brilliant tail feathers are an example of:
 

1. Sexual selection.
2. Natural selection.
3. Adaptation to the environment.
4. A feature with little apparent utility.


16. Which of the following circumstances are favorable to natural selection?
 

1. A large amount of inheritable and diversified variability.
2. A large number of individuals.
3. A large continental area.
4. All of the above.


17. Mendel’s work on genetics showed that:
 

1. All characteristics of a species are inherited.
2. No acquired characteristics can be passed on from one generation to the next.
3. The genetic information transmitted from on generation to the next is in the form of particles.
4. The ratio of dominant to recessive characteristics can never shift.


18. The effects of a new genetic mutation in a male is more likely to have a greater impact on his daughters than his sons because:
 

1. The sons receive both an X and Y chromosome from the father.
2. The sons receive only an X chromosome from the father.
3. The sons receive only a Y chromosome from the father.
4. None of the above.


19. Males are more likely to be color blind because:
 

1. Men have both an X and a Y chromosome.
2. Color blindness is due to a recessive gene.
3. The gene for color blindness is on the X chromosome.
4. All of the above.


20. The human eye is an example of a highly specialized organism. However, it is not a perfect organ of vision. Which of the following characteristics points to that imperfection.
 

1. The optic nerve is attached to the front of the retina.
2. Some eyes are nearsighted.
3. Some eyes are colorblind.
4. Some eyes are farsighted.