Living Environment August 2007 Questions Answer Keys
The University of the State of New York
Regents High School Examination
Thursday, August 16, 2007 — 12:30 to 3:30 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. Which condition would most likely upset the stability of an ecosystem?
- (1) a cycling of elements between organisms and the environment
- (2) energy constantly entering the environment
- (3) green plants incorporating sunlight into organic compounds
- (4) a greater mass of animals than plants
2. In 1910, Thomas Morgan discovered a certain pattern of inheritance in fruit flies known as sex linkage. This discovery extended the ideas of inheritance that Gregor Mendel had discovered while working with garden peas in 1865. Which principle of scientific inquiry does this illustrate?
- (1) A control group must be part of a valid experiment.
- (2) Scientific explanations can be modified as new evidence is found.
- (3) The same experiment must be repeated many times to validate the results.
- (4) Values can be used to make ethical decisions about scientific discovery.
3. As a human red blood cell matures, it loses its nucleus. As a result of this loss, a mature red blood cell lacks the ability to
- (1) take in material from the blood
- (2) release hormones to the blood
- (3) pass through artery walls
- (4) carry out cell division
4. Enzyme molecules normally interact with substrate molecules. Some medicines work by blocking enzyme activity in pathogens. These medicines are effective because they
- (1) are the same size as the enzyme
- (2) are the same size as the substrate molecules
- (3) have a shape that fits into the enzyme
- (4) have a shape that fits into all cell receptors
5. The diagram below represents three human body systems.
Which row in the chart below correctly shows what systems A, B, and C provide for the human body?
6. Which statement describes one function of the placenta in mammals?
- (1) It allows blood of the mother to mix with the blood of the fetus.
- (2) It contains fluid that protects the embryo from harm.
- (3) It removes waste products that are produced in the cells of the fetus.
- (4) It synthesizes food for the embryo.
7. The arrows in the diagram below indicate the movement of materials into and out of a singlecelled organism.
The movements indicated by all the arrows are directly involved in
- (1) the maintenance of homeostasis
- (2) respiration, only
- (3) excretion, only
- (4) the digestion of proteins
8. The brown summer feathers of ptarmigans, small Arctic birds, are replaced by white feathers after winter arrives. Which statement best explains this observation?
- (1) The expression of genes can be modified by the environment.
- (2) Holes in the ozone layer vary in size depending on the season.
- (3) Acids in rain bleach the brown feathers of the birds.
- (4) Mutations occur only during certain seasons.
9. A child has brown hair and brown eyes. His father has brown hair and blue eyes. His mother has red hair and brown eyes. The best explanation for the child having brown hair and brown eyes is that
- (1) a gene mutation occurred that resulted in brown hair and brown eyes
- (2) gene expression must change in each generation so evolution can occur
- (3) the child received genetic information from each parent
- (4) cells from his mother’s eyes were present in the fertilized egg
10. The diagram below represents a portion of a type of organic molecule present in the cells of organisms.
What will most likely happen if there is a change in the base sequence of this molecule?
- (1) The molecule will be converted into an inorganic compound.
- (2) The amino acid sequence may be altered during protein synthesis.
- (3) The chromosome number will decrease in future generations.
- (4) The chromosome number may increase within the organisms.
11. All cells in an embryo have the same DNA. However, the embryonic cells form organs, such as the brain and the kidneys, which have very different structures and functions. These differences are the result of
- (1) having two types of cells, one type from each parent
- (2) rapid mitosis causing mutations in embryo cells
- (3) new combinations of cells resulting from meiosis
- (4) certain genes being expressed in some cells and not in others
12. Viruses frequently infect bacteria and insert new genes into the genetic material of the bacteria. When these infected bacteria reproduce asexually, which genes would most likely be passed on?
- (1) only the new genes
- (2) only the original genes
- (3) both the original and the new genes
- (4) neither the original nor the new genes
13. A mutation changes a gene in a cell in the stomach of an organism. This mutation could cause a change in
- (1) both the organism and its offspring
- (2) the organism, but not its offspring
- (3) its offspring, but not the organism itself
- (4) neither the organism nor its offspring
14. A certain protein is found in mitochondria, chloroplasts, and bacteria. This provides evidence that plants and bacteria
- (1) have some similar DNA base sequences
- (2) can use carbon dioxide to make proteins
- (3) digest proteins into simple sugars
- (4) contain certain pathogenic microbes
15. Extinction of a species could result from
- (1) evolution of a type of behavior that produces greater reproductive success
- (2) synthesis of a hormone that controls cellular communication
- (3) limited genetic variability in the species
- (4) fewer unfavorable mutations in the species
16. The rate at which all organisms obtain, transform, and transport materials depends on an immediate supply of
- (1) ATP and enzymes
- (2) solar energy and carbon dioxide
- (3) carbon dioxide and enzymes
- (4) ATP and solar energy
17. As women age, their reproductive cycles stop due to decreased
- (1) digestive enzyme production
- (2) production of ATP
- (3) levels of specific hormones
- (4) heart rate
18. The evolutionary pathways of five species are represented in the diagram below.
Which statement is supported by the diagram?
- (1) Species C is the ancestor of species B.
- (2) Species D and E evolved from species B.
- (3) Species X evolved later than species D but before species B.
- (4) Both species C and species D are related to species X.
19. Which cell is normally produced as a direct result of meiosis?
- (1) a uterine cell having half the normal species number of chromosomes
- (2) an egg having the full species number of chromosomes
- (3) a zygote having the full species number of chromosomes
- (4) a sperm having half the normal species number of chromosomes
20. The diagram and chart below represent some of the changes a zygote undergoes during its development.
The processes that are most directly responsible for these changes are
- (1) sorting and recombination of genetic information
- (2) mitosis and differentiation
- (3) meiosis and adaptation
- (4) fertilization and cycling of materials
21. The diagram below shows the growth pattern of some skin cells in the human body after they have been exposed to ultraviolet radiation.
The cells in area X are most likely
- (1) red blood cells
- (2) cancer cells
- (3) white blood cells
- (4) sex cells
22. The diagram below represents a cross section of part of a leaf.
Which life functions are directly regulated through feedback mechanisms associated with the actions of the structures labeled X?
- (1) excretion and immunity
- (2) digestion and coordination
- (3) circulation and reproduction
- (4) respiration and photosynthesis
23. One irreversible effect of both deforestation and water pollution on the environment is the
- (1) extinction of species
- (2) thinning of the ozone shield
- (3) depletion of atmospheric carbon dioxide levels
- (4) increase in renewable resources
24. An energy pyramid containing autotrophs and other organisms from a food chain is represented below.
Carnivores would most likely be located in
- (1) level I, only
- (2) level I and level II
- (3) level III, only
- (4) level II and level III
25. Which statement describes a situation that leads to stability within an ecosystem?
- (1) Carbon dioxide and water are released only by abiotic sources in the ecosystem.
- (2) Interactions between biotic and abiotic components regulate carbon dioxide and water levels.
- (3) Animals provide the oxygen used by plants, and plants provide the nitrogen needed by animals.
- (4) Organisms provide all the necessary energy for the maintenance of this ecosystem.
26. Worms that had been invaded by bacteria were eaten by a species of bird. Many of these birds died as a result. The most likely explanation for this is that the
- (1) bacteria interfered with normal life functions of the birds
- (2) disease that killed the birds was inherited
- (3) gene alterations in the bacterial cells killed the birds
- (4) birds produced antigens in response to the bacteria
27. Which action illustrates an increased understanding and concern by humans for ecological interrelationships?
- (1) importing organisms in order to stabilize existing ecosystems
- (2) eliminating pollution standards for industries that promote technology
- (3) removing natural resources at a rate equal to the needs of the population
- (4) implementing laws to regulate the number of animals hunted and killed each year
28. The graph below represents the growth of a population of flies in a jar.
Which letter indicates the part of the graph that represents the carrying capacity of the environment in the jar?
- (1) A
- (2) B
- (3) C
- (4) D
29. One likely reason some experimental automobiles have been developed to use electricity rather than gasoline is that
- (1) gasoline is made from petroleum, a nonrenewable resource
- (2) Earth has an unlimited supply of fossil fuels
- (3) the use of electricity will eliminate the need for all antipollution laws
- (4) the use of electricity will increase the manufacture of antipollution devices for cars
30. Ecosystems will have a greater chance of maintaining equilibrium over a long period of time if they have
- (1) organisms imported by humans from other environments
- (2) a sudden change in climate
- (3) a diversity of organisms
- (4) predators eliminated from the food chains
Living Environment August 2007 Questions Answers Keys
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