IB Biology Exam Prep - Question List

Select how would you like to study

111.
Which of the following best describes the mechanism by which hemoglobin loads and unloads oxygen?
  1. Production of CO2 during cellular respiration lowers blood pH, which decreases the affinity of hemoglobin for oxygen and facilitates the unloading of oxygen to cells.
  2. Oxygen molecules binding to one subunit of a hemoglobin molecule change its shape, and the other three subunits also change shape and accept oxygen more readily.
  3. Blood arriving at the lungs has a lower PO2 pressure than the air inside the lungs, which favors the diffusion of oxygen into the blood from the lungs.
  4. Carbon dioxide in the blood as a result of increased cellular respiration causes the heart's pacemaker to speed up and increase the transport of oxygen to cells.
112.
The sensation of thirst is produced by the brain primarily in response to signals from the body indicating:
  1. Decreased heart rate and blood pressure.
  2. Increased internal temperatures.
  3. Decreased urinary output by the kidneys.
  4. Increased osmolarity of the blood.
113.
Which of the following best describes a difference between the peripheral nervous system and the central nervous system?
  1. Axons within the peripheral nervous system are longer since they must stretch from cell bodies in the ganglia located along the spine to their destinations in the tissues.
  2. Nerve cells that are located within the peripheral nervous system have many more dendrites than those that are located within the central nervous system.
  3. Synapses within the peripheral nervous system are electrical rather than chemical and so do not require the use of neurotransmitters to transmit information.
  4. Impulses in the peripheral nervous system carry information from the body to the brain, while those in the central nervous system carry it from the brain to the body.
114.
In invertebrates, the speed at which an action potential travels along an axon is directly proportional to the axon's diameter. However, vertebrate axons have narrow diameters, but can still conduct action potentials at very high speeds. This is true because vertebrate axons:
  1. Contain higher concentrations of water that increase the conductivity.
  2. Possess a lipid-rich myelin sheath that functions as electrical insulation.
  3. Operate at higher body temperatures that reduce electrical resistance.
  4. Generate action potentials that use sodium rather than calcium to generate electrical impulses.
115.
Which of the following best describes the role played by the hormone oxytocin in human reproduction?
  1. Inducing and regulating uterine contractions during the various stages of labor.
  2. Stimulating the growth of follicles in the ovary and maturation of the oocytes.
  3. Inducing and regulating the disintegration of the uterine lining during menstruation.
  4. Stimulating the development of the endometrium in preparation for pregnancy.

Select how would you like to study