93' SBIOA Exam

PART A:  MULTIPLE CHOICE.  THERE IS AN ANSWER PAGE FOR THESE QUESTIONS.  USE IT.

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22 .   The cell structure where most of the protein sysnthesis  takes place is the

       a .    cell wall.

       b .         nucleolous.

       c .         nucleus.

       d .         nuclear membrane.

       e .         r*correct*ibosome.

23 .   The precise sequence of amino acids in a protein is determined by

       a .    *correct*a nucleotide sequence.

       b .    the location of disulphide bridges.

       c .     its tertiary structure.

       d .         another protein.

       e .    the hydrogen bonds.

24 .   A repressor protein

       a .         prevents the action of a regulatory gene.

       b .         *correct*blocks the gene transcription.

       c .         suppresses the action of antibodies.

       d .         prevents any interference with the binding of RNA polymerase to DNA.    

       e .         reduces the rate of secretion of antibodies.

25 .        Radiation causes a gene mutation in a diploid somatic cell undergoing mitosis. What would be the result of this event?

       a .    The mutation will become part of the gene pool of  successive generations.

       b .    The entire species will be affected.

       c .         *correct*Future generations will not be affected.

       d .    The gametes will also be affected.

       e .    In time, all neighbouring cells will be affected.

26 .   If all four possible blood types are represented in the offspring of the same parents, the phenotypes of the parents must be

       a .    both type AB

       b .    both type O

       c .     type AB and type O

       d .    *correct* type A and type B

       e .    type B and type O

27 .   If a couple have had 2 boys and a girl, what are the chances that their next child will be a girl?

       a .    25%

       b .    33%

       c .     *correct*50%

       d .    66%

       e .    100%

28 .   The most effective portion of the spectrum for photosynthesis is the

       a .         wavelengths shorter than the visible spectrum.

       b .         yellow portion of the spectrum.

       c .         wavelengths longer than the visible spectrum.

       d .    *ans*red portion of the spectrum.

       e .         green portion of the spectrum.

29 .   During photosynthesis, the free oxygen produced comes from

       a .         *ans*water.

       b .         glucose or starch.

       c .         carbon dioxide.

       d .    a five-carbon compound.

       e .         chlorophyll.

30 .   The light-dependent reaction of photosynthesis is marked by the

       a .         production of ATP, carbon dioxide and reducing power.

       b .         *ans*production of NADPH+H⁺ and ATP.

       c .         reduction of oxygen and the production of NADPH₊H⁺

       d .         reduction of carbon dioxide and the release of oxygen.

       e .    the fixation of carbon dioxide with the energy of ATP.

31 .   The role of water in photosynthesis is to

       a .         provide energy.

       b .         activate chlorophyll.

       c .         refract intense sunlight.

       d .         supply oxygen.

       e .         *ans*supply free electrons.

32 .   During photosynthesis, the electrons released as a result of photolysis

       a .         *ans*reduce chlorophyll molecules in photosystem II.

       b .         oxidize a molecule of NADP⁺.

       c .     are directly involved in the fixation of carbon during  the Calvin cycle.

       d .         combine with hydrogen ions and oxygen to form water.

       e .         reduce the chlorophyll molecules in photosystem I.

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