34. When considering the average food chain, which of the following statements is true?
(A) Secondary consumers are the most abundant organisms in an ecosystem.
(B)The longer the food chain, the more stable the ecosystem.
(C) Biomass decreases moving up the food chain.
(D) The trophic level with the highest species abundance is usually the primary producers.

30. A plant has sluggish wound healing abilities as well as an inability to store significant food reserves. If you could enhance the growth of a tissue to improve these properties, which tissue would you enhance? (A) parenchyma of the stem cortex (B)root apical meristem (C) periderm (D) lateral meristem

31. Chemical cues that help guide a developing pollen tube toward an ovule are released by the _____.(A) antipodal cells (B)synergids (C) egg (D) central cell (E)sperm

32. In the logistic growth model of population growth, at what population size - in terms of the carrying capacity (K) - is the population increasing most rapidly? (A) K (B)K/2 (C) K/3 (D) K/4

33. What is the main reason leading to a uniform dispersion pattern among individuals within a population? (A) Competition (B)Mutualism (C) Resource availability (D) Environmental factors

35. Which of the following statements is   not   true? (A) The risk of stroke can be reduced by avoiding the damage to endothelium of vessels. (B)Increased sympathetic activity raises blood pressure by increasing the strength and rate of the heartbeat. (C) The left ventricle pumps the same amount of blood as the right ventricle. (D) If action potential propagation through the bundle of His was blocked, the SA node would no longer set the pace for atrial contraction. (E)The velocity of blood flow in the veins is faster than that in the capillaries.

36. If adenylyl cyclase were inhibited in animal cells, _____.(A) binding of epinephrine to beta receptors would have no effect on cyclic AMP levels. (B)binding of epinephrine to beta receptors would have no effect on G-protein activation. (C) an increase in mRNA for cyclic AMP would occur. (D) epinephrine would not be able to bind to beta receptors.

1. Imagine that a cell had no motor proteins. Which processes would not be able to occur? (A) RNA transcription (B)fertilization of an egg by a sperm cell (C)protein translation (D)maintenance of cell rigidity (E)action potential of a neuron

2. For a neuron with an initial membrane potential at -80 mV, an increase in the extracellular concentration of potassium ions from 5 mM to 35 mM would result in _____.(A) depolarization of the neuron (B)hyperpolarization of the neuron (C)net diffusion of potassium ions into the cell (D)no change in the membrane potential

3. If the afferent nerves from the carotid and aortic bodies are cut in a rat, (A) a decrease in arterial PCO2 will stimulate increased ventilation. (B)an increase of PCO2 in the cerebrospinal fluid will no longer stimulate increased ventilation. (C)an increase in arterial lactic acid (metabolic acid) will no longer stimulate increased ventilation. (D)an increase in arterial PCO2 will no longer stimulate increased ventilation. (E)a decrease in arterial PO2 will stimulate increased ventilation.

1. A boy wants to row across a river in the shortest possible time. He can row at 2 m/s in still water and the river is flowing at 1 m/s. At what angle θ should he point the bow (front) of his boat? (A) 30° (B) 45° (C) 60° (D) 53° (E) 90°.