#Question id: 10330

#Unit 9. Diversity of Life Forms

If the eukaryotic condition arose, independently, several different times during evolutionary history, and if ancestors of these different lineages are extant and are classified in the domain Eukarya, then the domain Eukarya would be

#Question id: 10331

#Unit 9. Diversity of Life Forms

When using a cladistic approach to systematics, which of the following is considered most important for classification?

#Question id: 10332

#Unit 9. Diversity of Life Forms

The four-chambered hearts of birds and the four-chambered hearts of mammals evolved independently of each other. If one were unaware of this independence, then one might logically conclude that

#Question id: 10333

#Unit 6. System Physiology – Plant

Four elements, oxygen, carbon, and hydrogen and nitrogen are the major components of most organic compounds, which of the following elements are more abundant in plants ?

#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: 10335

#Unit 6. System Physiology – Plant

plants can store high levels of nitrate, and they can translocate it from tissue to tissue without deleterious effect. Yet if livestock or humans consume plant material that is high in nitrate, they may suffer with,