Living Environment January 2006 Questions Answer Keys
The University of the State of New York
Regents High School Examination
Friday, January 27, 2006 — 9:15 a.m. to 12:15 p.m., only
Student Name _____________________________________________________________
School Name ______________________________________________________________
Directions (1–30): For each statement or question, write on your separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question.
1. In the diagram below, what does X most likely represent?
- (1) autotrophs
- (2) herbivores
- (3) decomposers
- (4) carnivores
2. Two closely related species of birds live in the same tree. Species A feeds on ants and termites, while species B feeds on caterpillars. The two species coexist successfully because
- (1) each occupies a different niche
- (2) they interbreed
- (3) they use different methods of reproduction
- (4) birds compete for food
3. After a hormone enters the bloodstream, it is transported throughout the body, but the hormone affects only certain cells. The reason only certain cells are affected is that the membranes of these cells have specific
- (1) receptors
- (2) tissues
- (3) antibodies
- (4) carbohydrates
4. A characteristic of a DNA molecule that is not characteristic of a protein molecule is that the DNA molecule
- (1) can replicate itself
- (2) can be very large
- (3) is found in nuclei
- (4) is composed of subunits
5. The graph below illustrates the relative amounts of product formed by the action of an enzyme in a solution with a pH of 6 at seven different temperatures.
Which statement best expresses the amount of product that will be formed at each temperature if the experiment is repeated at a pH of 4?
- (1) The amount of product formed will be equal to that produced at pH 6.
- (2) The amount of product formed will be greater than that produced at pH 6.
- (3) The amount of product formed will be less than that produced at pH 6.
- (4) The amount of product formed can not be accurately predicted.
6. Which statement best explains the fact that some identical twins appear different from one another?
- (1) Their DNA is essentially the same and the environment plays little or no role in the expression of their genes.
- (2) Their DNA is very different and the environment plays a significant role in the expression of their genes.
- (3) Their DNA is very different and the environment plays little or no role in the expression of their genes.
- (4) Their DNA is essentially the same and the environment plays a significant role in the expression of their genes.
7. Which statement best expresses the relationship between the three structures represented below?
- (1) DNA is produced from protein absorbed by the cell.
- (2) Protein is composed of DNA that is produced in the cell.
- (3) DNA controls the production of protein in the cell.
- (4) Cells make DNA by digesting protein.
8. The diagram below represents a common laboratory technique in molecular genetics.
One common use of this technology is the
- (1) production of a human embryo to aid women who are unable to have children
- (2) change of single-celled organisms to multicellular organisms
- (3) introduction of a toxic substance to kill bacterial cells
- (4) production of hormones or enzymes to replace missing human body chemicals
9. Which statement provides accurate information about the technique illustrated below?
- (1) This technique results in offspring that are genetically identical to the parents.
- (2) New varieties of organisms can be developed by this technique known as selective breeding.
- (3) This technique is used by farmers to eliminate mutations in future members of the species.
- (4) Since the development of cloning, this technique is no longer used in agriculture.
10. Thousands of years ago, giraffes with short necks were common within giraffe populations. Nearly all giraffe populations today have long necks. This difference could be due to
- (1) giraffes stretching their necks to keep their heads out of reach of predators
- (2) giraffes stretching their necks so they could reach food higher in the trees
- (3) a mutation in genetic material controlling neck size occurring in some skin cells of a giraffe
- (4) a mutation in genetic material controlling neck size occurring in the reproductive cells of a giraffe
11. Estrogen has a direct effect on the
- (1) formation of a zygote
- (2) changes within the uterus
- (3) movement of an egg toward the sperm
- (4) development of a placenta within the ovary
12. A new chemical was discovered and introduced into a culture containing one species of bacteria. Within a day, most of the bacteria were dead, but a few remained alive. Which statement best explains why some of the bacteria survived?
- (1) They had a genetic variation that gave them resistance to the chemical.
- (2) They were exposed to the chemical long enough to develop a resistance to it.
- (3) They mutated and became a different species after exposure to the chemical.
- (4) They absorbed the chemical and broke it down in their digestive systems.
13. A current proposal in the field of classification divides life into three broad categories called domains. This idea is illustrated below.
Which concept is best supported by this diagram?
- (1) Evolutionary pathways proceed only in one set direction over a short period of time.
- (2) All evolutionary pathways will eventually lead to present-day organisms.
- (3) All evolutionary pathways are the same length and they all lead to present-day organisms.
- (4) Evolutionary pathways can proceed in several directions with only some pathways leading to present-day organisms.
14. After the union of sperm and egg, the singlecelled zygote develops into a multicellular organism with specialized cells by the processes of
- (1) meiosis and replication
- (2) mitosis and differentiation
- (3) cloning and growth
- (4) fertilization and gamete production
15. A certain plant species, found only in one particular stream valley in the world, has a very shallow root system. An earthquake causes the stream to change its course so that the valley in which the plant species lives becomes very dry. As a result, the species dies out completely. The effect of this change on this plant species is known as
- (1) evolution
- (2) extinction
- (3) mutation
- (4) succession
16. When a planarian (a type of worm) is cut in half, each half usually grows back into a complete worm over time. This situation most closely resembles
- (1) asexual reproduction in which a mutation has occurred
- (2) sexual reproduction in which each half represents one parent
- (3) asexual reproduction of a single-celled organism
- (4) sexual reproduction of a single-celled organism
17. Which statement describes the reproductive system of a human male?
- (1) It releases sperm that can be used only in external fertilization.
- (2) It synthesizes progesterone that regulates sperm formation.
- (3) It produces gametes that transport food for embryo formation.
- (4) It shares some structures with the excretory system.
18. The immune system of humans may respond to chemicals on the surface of an invading organism by
- (1) releasing hormones that break down these chemicals
- (2) synthesizing antibodies that mark these organisms to be destroyed
- (3) secreting antibiotics that attach to these organisms
- (4) altering a DNA sequence in these organisms
19. Which statement about the gametes represented in the diagram below is correct?
- (1) They are produced by females.
- (2) They are fertilized in an ovary.
- (3) They transport genetic material.
- (4) They are produced by mitosis.
20. The dissolved carbon dioxide in a lake is used directly by
- (1) autotrophs
- (2) parasites
- (3) fungi
- (4) decomposers
21. Which transplant method would prevent the rejection of tissue after an organ transplant?
- (1) using organs cloned from the cells of the patient
- (2) using organs produced by genetic engineering to get rid of all proteins in the donated organs
- (3) using organs only from pigs or monkeys
- (4) using an organ donated by a close relative because the proteins will always be identical to those of the recipient
22. Ten breeding pairs of rabbits are introduced onto an island with no natural predators and a good supply of water and food. What will most likely happen to the rabbit population?
- (1) It will remain relatively constant due to equal birth and death rates.
- (2) It will die out due to an increase in the mutation rate.
- (3) It will increase until it exceeds carrying capacity.
- (4) It will decrease and then increase indefinitely.
23. Vaccinations help prepare the body to fight invasions of a specific pathogen by
- (1) inhibiting antigen production
- (2) stimulating antibody production
- (3) inhibiting white blood cell production
- (4) stimulating red blood cell production
24. All cells of an organism are engaged in many different chemical reactions. This fact is best supported by the presence in each cell of thousands of different kinds of
- (1) enzymes
- (2) nuclei
- (3) chloroplasts
- (4) organelles
25. Nutritional relationships between organisms are shown in the diagram below.
The mouse population would most likely decrease if there were
- (1) an increase in the frog and tree populations
- (2) a decrease in the snake and hawk populations
- (3) an increase in the number of decomposers in the area
- (4) a decrease in the amount of available sunlight
26. Even before a flower bud opens, certain plant chemicals have colored the flower in patterns particularly attractive to specific insects. At the same time, these chemicals protect the plant’s reproductive structures by killing or inhibiting pathogens and insects that may feed on the plant. Which statement about the plant and the other organisms mentioned is correct?
- (1) Chemicals affect plants but not animals.
- (2) Organisms of every niche may be preyed on by herbivores.
- (3) Any chemical produced in a plant can protect against insects.
- (4) Organisms may interact with other organisms in both positive and negative ways.
27. A fire burns an oak forest down to bare ground. Over the next 150 years, if the climate remains constant, this area will most likely
- (1) remain bare ground
- (2) return to an oak forest
- (3) become a rain forest
- (4) become a wetland
28. Continued depletion of the ozone layer will most likely result in
- (1) an increase in skin cancer among humans
- (2) a decrease in atmospheric pollutants
- (3) an increase in marine ecosystem stability
- (4) a decrease in climatic changes
29. A change in the acidity of mountain lakes would most likely be a result of
- (1) ecological succession of the area at the top of the mountain
- (2) the introduction of new species into the lakes
- (3) air pollution from smoke stacks miles away
- (4) planting grasses and shrubs around the lakes
30. A forest is cut down and is replaced by a cornfield. A negative consequence of this practice is
- (1) an increase in the carbon dioxide released into the atmosphere
- (2) an increase in the size of predators
- (3) a decrease in biodiversity
- (4) a decrease in the amount of soil that is washed away during rainstorms
Living Environment January 2006 Questions Answers Keys
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