Question

The European honey bee, Apis mellifera, is the most common species of honey bee in the world, and colonies were first introduced into the United States by early European settlers in the 17th century. In the centuries since then, honey bees have become enormously valuable for their ecological and commercial contributions. Many crops rely on honey bee pollination, particularly almond orchards, which use more than one million of the 2.4 million managed honey bee colonies in the U.S. Though most people are fearful of honey bees and their stings, a honey bee will only sting if it is near the hive and perceives a threat. A honey bee sting secretes venom, comprised mostly of the biologically active molecule melittin. Melittin is a small peptide and acts as a cell membrane lytic factor, inhibiting the sodium (Na+)/potassium (K+) transport pump and ATP synthase.

Part 1. Which of the following process(es) would be disabled in cells exposed to melittin?
A. The release of neurotransmitters from the presynaptic membrane of neurons and failure to stimulate an action potential in the postsynaptic neuron membrane.
B. The movement of Na+ ions into the neuron and K+ ions out of the neuron during an action potential.
C. The electron transport chain in aerobic respiration and the light-dependent reactions of photosynthesis.
D. The Krebs cycle in aerobic respiration and the Calvin cycle in photosynthesis.

Answer 1

Cells exposed to melittin would have disrupted processes involving the sodium-potassium pump and ATP synthase, leading to the disabling of the electron transport chain in aerobic respiration and the light-dependent reactions of photosynthesis.

Step-by-step explanation:

The question asks which processes would be disabled in cells exposed to melittin, which is the biologically active molecule found in honey bee venom. Melittin disrupts cell membranes and inhibits the sodium-potassium pump and ATP synthase. The processes affected by this inhibition would be:

• The release of neurotransmitters from the presynaptic membrane of neurons (A), since the sodium-potassium pump is crucial for restoring the ionic conditions after an action potential, which is necessary for neurotransmitter release.
• The movement of Na+ ions into the neuron and K+ ions out of the neuron during an action potential (B), as this directly involves the action of the sodium-potassium pump.
• The electron transport chain in aerobic respiration and the light-dependent reactions of photosynthesis (C), since ATP synthase is part of these processes and its inhibition would hamper the production of ATP.

Therefore, the correct answer is C: The electron transport chain in aerobic respiration and the light-dependent reactions of photosynthesis would be disabled in cells exposed to melittin.