#Question id: 10334

#Unit 6. System Physiology – Plant

N2 combines with hydrogen to form ammonia under elevated temperature (about 200°C) and high pressure (about 200 atmospheres) and in the presence of a metal catalyst (usually iron). The extreme conditions are required to overcome the high activation energy of the reaction. This nitrogen fixation reaction, called

#Question id: 4930

#Unit 11. Evolution and Behavior

Which of the following is the correct sequence of events in the origin of life?

I. Formation of protocells

II. Synthesis of organic monomers

III. Synthesis of organic polymers

IV. Formation of DNA-based genetic systems

#Question id: 3011

#Unit 2. Cellular Organization

Bacteria that may form endospores include

#Question id: 11211

#Unit 7. System Physiology – Animal

The following steps refer to various stages in transmission at a chemical synapse.

1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.

2. Calcium ions rush into neuron's cytoplasm.

3. An action potential depolarizes the membrane of the presynaptic axon terminal.

4. The ligand-gated ion channels open.

5. The synaptic vesicles release neurotransmitter into the synaptic cleft.

Which sequence of events is correct?

#Question id: 21283

#Unit 12. Applied Biology